阅读说明：本技术 将艳灰色印刷于塑料卡上的方法和系统 (Method and system for printing brilliant gray on plastic cards ) 是由 M·阿亚拉 H·马士贝克 R·K·朱丽亚兹甘 J·克纳克 W·克拉托普 于 2019-05-31 设计创作，主要内容包括：本发明公开了用于将艳灰色印刷于塑料卡上的方法和系统。可单独地或以其任何组合使用的下述特征可实施以实现所述艳灰色：1)CMYK颜料油墨的使用以实现CMYK印刷；2)像素提取过程和/或印刷陷印过程；3)两个独立印刷命令,包括CMY(或CMYK)+混合印刷命令以及K+混合印刷命令；和4)适当的卡设置。(Methods and systems for printing a bright gray color on a plastic card are disclosed. The following features, which may be used alone or in any combination thereof, may be implemented to achieve the bright gray color: 1) use of CMYK pigment inks to achieve CMYK printing; 2) a pixel extraction process and/or a print trapping process; 3) two independent print commands, including a CMY (or CMYK) + blend print command and a K + blend print command; and 4) appropriate card settings.)

1. A method of printing on a surface of a plastic card in a plastic card printing mechanism, the method comprising:

a) obtaining a source digital image;

b) scanning each pixel of the source digital image to identify each pixel as color or monochrome;

c) generating a color digital image from the identified color pixels and a monochrome digital image from the identified monochrome pixels;

d) wherein, c) comprises: for the color digital image, replacing each pixel at the coordinates corresponding to the monochrome pixel with a white pixel; and

e) wherein, c) also includes: for the monochrome digital image, replacing each pixel at the coordinates for the color pixels with a white pixel; and

f) sending the color digital image and the monochrome digital image to the plastic card printing mechanism and printing the color digital image on a surface of the plastic card using cyan, magenta, and yellow pigment inks and printing the monochrome digital image on a surface of the plastic card using black pigment ink to produce a combined image on the surface.

2. The method of claim 1 wherein f) comprises printing the color digital image and the monochrome digital image on a transferable print-receptive layer of retransfer material to produce the combined image, and thereafter transferring the transferable print-receptive layer comprising the combined image to a surface of the plastic card.

3. The method of claim 1, wherein the source digital image includes two or more of a background image, a card issuer name, a card issuer identification, a personal account number, a cardholder name, an expiration date, a payment network name, and a payment network identification.

4. The method of claim 1, wherein the plastic card comprises a financial card having at least one of a magnetic stripe and an integrated circuit chip.

5. The method of claim 1, wherein c) further comprises:

1) for the color digital image, determining whether red, green, blue (RGB) values of each pixel of the source digital image are substantially equal, and for each pixel of the source digital image in which the RGB values are substantially equal, replacing each pixel having equal RGB values with a white pixel; and

2) for the monochrome digital image, each pixel at the coordinates corresponding to the pixel replaced in 1) is replaced with a gray pixel.

6. The method of claim 1 wherein c) further comprises applying a print trap when generating the color digital image and applying a print trap when generating the monochrome digital image.

7. The method of claim 6, wherein applying a print trap when generating the color digital image comprises:

scanning each pixel in the source digital image to detect a monochrome pixel;

for each detected monochrome pixel, determining whether there is an adjacent color pixel;

i) adding the detected monochrome pixels to the color digital image if there are neighboring color pixels; and

ii) if there is no neighboring color pixel, changing the detected monochrome pixel to a white pixel.

8. The method of claim 6, wherein applying a print trap when generating the monochrome digital image comprises:

scanning each pixel in the source digital image to detect color pixels;

for each detected color pixel, determining whether there is an adjacent monochrome pixel;

if there is a neighboring monochrome pixel, the detected color pixel is changed to a monochrome pixel and added to the monochrome digital image.

9. The method of claim 6, wherein the source digital image includes two or more of a background image, a card issuer name, a card issuer identification, a personal account number, a cardholder name, an expiration date, a payment network name, and a payment network identification.

10. The method of claim 6, wherein the plastic card comprises a financial card having at least one of a magnetic stripe and an integrated circuit chip.

11. A method of printing on a surface of a plastic card in a plastic card printing mechanism, the method comprising:

a) obtaining a source digital image;

b) scanning each pixel of the source digital image to identify each pixel as color or monochrome;

c) generating a color digital image from the identified color pixels and a monochrome digital image from the identified monochrome pixels;

d) wherein, c) comprises: for the color digital image, determining whether red, green, blue (RGB) values of each pixel of the source digital image are substantially equal, and for each pixel of the source digital image in which the RGB values are substantially equal, replacing each pixel having equal RGB values with a white pixel;

e) wherein, c) also includes: for the monochromatic digital image, replacing each pixel at the coordinates corresponding to the pixel replaced in d) with a gray pixel; and

f) sending the color digital image and the monochrome digital image to the plastic card printing mechanism and printing the color digital image on a surface of the plastic card using cyan, magenta, and yellow pigment inks and printing the monochrome digital image on a surface of the plastic card using black pigment ink to produce a combined image on the surface.

12. The method of claim 11 wherein f) comprises printing the color digital image and the monochrome digital image on a transferable print-receptive layer of retransfer material to produce the combined image, and thereafter transferring the transferable print-receptive layer comprising the combined image to a surface of the plastic card.

13. The method of claim 11, wherein the source digital image includes two or more of a background image, a card issuer name, a card issuer identification, a personal account number, a cardholder name, an expiration date, a payment network name, and a payment network identification.

14. The method of claim 11, wherein the plastic card comprises a financial card having at least one of a magnetic stripe and an integrated circuit chip.

15. The method of claim 11 wherein c) further comprises pixel extraction for the color digital image and pixel extraction for the monochrome digital image.

16. The method of claim 11, wherein c) further comprises applying a print trap when generating the color digital image and applying a print trap when generating the monochrome digital image.

17. The method of claim 16, wherein applying a print trap when generating the color digital image comprises:

scanning each pixel in the source digital image to detect a monochrome pixel;

for each detected monochrome pixel, determining whether there is an adjacent color pixel;

1) adding the detected monochrome pixels to the color digital image if there are neighboring color pixels; and

2) if there is no neighboring color pixel, the detected monochrome pixel is changed to a white pixel.

18. The method of claim 16, wherein applying a print trap when generating the monochrome digital image comprises:

scanning each pixel in the source digital image to detect color pixels;

for each detected color pixel, determining whether there is an adjacent monochrome pixel;

if there is a neighboring monochrome pixel, the detected color pixel is changed to a monochrome pixel and added to the monochrome digital image.

19. The method of claim 16, wherein the source digital image includes two or more of a background image, a card issuer name, a card issuer identification, a personal account number, a cardholder name, an expiration date, a payment network name, and a payment network identification.

20. The method of claim 16, wherein the plastic card comprises a financial card having at least one of a magnetic stripe and an integrated circuit chip.

Technical Field

The present disclosure relates generally to printing on plastic cards including, but not limited to, financial (e.g., credit, debit, etc.) cards, driver's licenses, national identification cards, commercial identification cards, gift cards, and other plastic cards.

Background

Plastic cards are typically printed using a suitable printing mechanism in the card processing system. One known plastic card printing mechanism is a retransfer printing machine. Retransfer printing is a known printing process in which an image is printed on an intermediate retransfer material by a printing mechanism. After image printing, the intermediate retransfer material is transferred by lamination to the surface of the plastic card that bears the printed image. Additional information regarding retransfer printing can be found, for example, in U.S. patent 6894710, which is incorporated herein by reference in its entirety. Another known plastic card printing mechanism is a direct-to-card printing mechanism, in which print is applied directly to the surface of a plastic card from a print ribbon.

Most plastic card printing utilizes CMY printing, rather than CMYK. Printing black text and bar codes using black dye printing lacks sufficient density (i.e., darkness), so gray printing is instead performed using cyan (C), magenta (M), and yellow (Y) mixed together. These composite gray colors tend to have cyan, magenta, or yellow hues due to the limitation that C, M and Y cannot be continuously balanced to produce a neutral gray color.

Disclosure of Invention

Methods and systems for printing gray (vibrant grey) and/or special colorant materials (e.g., gold, silver) on plastic cards, such as financial (e.g., credit, debit, etc.) cards, drivers' licenses, national identification cards, commercial identification cards, gift cards, and other plastic or composite cards, that carry personalization data unique to the cardholder or specifically assigned to the cardholder and/or carry other card information. As used herein, the term "plastic card" is intended to encompass cards that are completely or substantially plastic, and cards that have non-plastic or composite components, as well as cards that have other formulations that function as the type of card indicated above. The cards covered by the term "plastic cards" typically carry printed personalization data unique to or specifically assigned to the cardholder, such as the cardholder's name, account, facial image of the cardholder, and the like. In some embodiments, the card may include a magnetic stripe and/or an integrated circuit chip that holds/stores personalization data unique to the cardholder or specifically assigned to the cardholder.

The four features described herein, which can be used alone or in any combination thereof, can be used to achieve a bright gray color printed on a plastic card. The four features include: 1) use of CMYK pigment inks to achieve CMYK printing; 2) a pixel extraction process and/or a printing trapping (trapping) process; 3) two independent print commands, including CMY (or CMYK) + print trap/mix print command and K (black) + print trap/mix print command; and 4) appropriate card settings.

Cards printed in bright gray as described herein are also referred to as bright gray cards. A gray card is a plastic card in which any portion of the surface of the plastic card is printed in one or more gray colors. In some embodiments, the bright gray color may form a background image that is printed on the front or back of the plastic card. In other embodiments, the bright gray color may form text that is printed on the front or back of the plastic card. The bright gray color described herein can form any print on any surface (i.e., the front and/or back) of the plastic card.

The term color as used herein can refer to colors other than those (e.g., gray, black, white, gold, and/or silver, etc.) presented by a monochromatic band (e.g., black, gold, silver, etc.), such as red, green, blue, yellow, etc. The surface of the gray card described herein can be completely printed gray in one or more shades of gray. The surface may also include a printed black and/or white color formed by a plastic card substrate or by printing ink to achieve a white color. The surface may also include printed colors such as CMY, red, green, blue, colors derived from a combination of CMY, and the like.

Printing on the surface of the plastic card as described herein includes retransfer printing, direct-to-card printing, and any other printing technique that employs CMYK printing that results in a gray color printed on the surface of the plastic card.

In one embodiment, a method of printing on a surface of a plastic card in a plastic card printing mechanism can include obtaining a source digital image. Each pixel of the source digital image is then scanned to identify each pixel as being color or monochrome. A color digital image is generated from the identified color pixels and a monochrome digital image is generated from the identified monochrome pixels. To generate a color digital image, it is determined whether red, green, blue (RGB) values of each pixel of the source digital image are substantially equal, and for each pixel of the source digital image in which the RGB values are substantially equal, each pixel having substantially equal RGB values is replaced with a white pixel. Further, to generate a monochrome digital image, each pixel at coordinates corresponding to a replacement pixel in a color digital image is replaced with a gray pixel. The color digital image and the monochrome digital image are then sent to a plastic card printing mechanism, and the color digital image is printed on the surface of the plastic card with cyan, magenta, and yellow pigment inks, and the monochrome digital image is printed on the surface of the plastic card with black pigment ink to produce a combined image on the surface.

In one embodiment, when printing on the surface of a plastic card, two images are generated: one image (color image) for CMY color stripes and another image (monochrome image) for single color stripes (e.g., black, gold, silver, etc.). In some embodiments, the single color band may be a color band. It should be appreciated that there may be several ways to achieve this goal. In one embodiment, the source image may be used as a template for producing color images and monochrome images. In such embodiments, the color image and the monochrome image have the same dimensions (e.g., width and height) as the source image. Initially, when color and monochrome images are produced, the color and monochrome images may be all white, black, or other colors undefined in the pixel composition. After color image and monochrome image creation, the source image can be scanned (e.g., pixel-by-pixel). The methods and systems described herein may determine an image (color or monochrome) that replicates (or delineates) pixels at x and y coordinates corresponding to the original locations of the pixels on a source image. In another embodiment, the source image may be used as a color image, and a monochrome image (equal size of the source image) may be produced by: the method includes scanning a source image, checking for pixels of the source image that should be copied (painted) onto a monochromatic image (via the methods and systems described herein), and, after copying the pixels of the source image to the monochromatic image, replacing the pixels on the color image with white pixels (indicating that the pixels are not rendered by, for example, CMY color bands). In yet another embodiment, the source image may be used as a monochromatic image, and a color image (equal size of the source image) may be produced by: the method comprises scanning the source image, checking the pixels of the source image that should be copied (painted) onto the color image (via the method and system described herein), and, after copying the pixels of the source image onto the color image, replacing the pixels on the monochrome image with white pixels (a concept known as punch-out).

In another embodiment, a method of printing on a surface of a plastic card in a plastic card printing mechanism can include obtaining a source digital image. Each pixel of the source digital image is then scanned to identify each pixel as either color or monochrome, and a color digital image is generated from the identified color pixels and a monochrome digital image is generated from the identified monochrome pixels. Applying a print trap when generating a color digital image; and when generating a monochrome digital image, also applying a print trap. The color digital image and the monochrome digital image are then sent to a plastic card printing mechanism, and the color digital image is printed on the surface of the plastic card with cyan, magenta, and yellow pigment inks, and the monochrome digital image is printed on the surface of the plastic card with black pigment ink to produce a combined image on the surface.

In yet another embodiment, a method of printing on a surface of a plastic card in a plastic card printing mechanism can include obtaining a source digital image. Each pixel of the source digital image is then scanned to identify each pixel as being color or monochrome. A color digital image is generated from the identified color pixels and a monochrome digital image is generated from the identified monochrome pixels. To generate a color digital image, it is determined whether red, green, blue (RGB) values of each pixel of the source digital image are substantially equal, and for each pixel of the source digital image in which the RGB values are substantially equal, each pixel having substantially equal RGB values is replaced with a white pixel. Further, when a color digital image is generated, a printing trap is applied. Further, to generate a monochrome digital image, each pixel at coordinates corresponding to a replacement pixel in a color digital image is replaced with a gray pixel. Further, when a monochrome digital image is generated, print trapping is also applied. The color digital image and the monochrome digital image are then sent to a plastic card printing mechanism, and the color digital image is printed on the surface of the plastic card with cyan, magenta, and yellow pigment inks, and the monochrome digital image is printed on the surface of the plastic card with black pigment ink to produce a combined image on the surface.

In yet another embodiment, a plastic card printing mechanism for printing on a surface of a plastic card is disclosed. The plastic card printing mechanism may include a print head. The plastic card printing mechanism may also include a print ribbon having cyan, magenta, yellow, and black pigmented ink ribbon plates. The plastic card printing mechanism may also include a controller. The controller may be configured to scan each pixel of the source digital image to identify each pixel as being color or monochrome. The controller may be further configured to generate a color digital image from the identified color pixels and a monochrome digital image from the identified monochrome pixels. The controller may also be configured to perform at least one of: a) for a color digital image, replacing each pixel at the coordinates corresponding to a monochrome pixel with a white pixel, and for a monochrome digital image, replacing each pixel at the coordinates corresponding to a color pixel with a white pixel; b) applying a print trap when generating a color digital image, and applying a print trap when generating a monochrome digital image; c) a) and b); d) 1) for a color digital image, determining whether red, green, blue (RGB) values of each pixel of the source digital image are substantially equal, and for each pixel of the source digital image in which the RGB values are substantially equal, replacing each pixel having equal RGB values with a white pixel, and 2) for a monochrome digital image, replacing each pixel at coordinates corresponding to the replaced pixel in 1) with a gray pixel; or e), b) and d). Additionally, the controller may be configured to send the color digital image and the monochrome digital image to a plastic card printing mechanism. The plastic card printing mechanism may be configured to print a color digital image on a surface of a plastic card using cyan, magenta, and yellow pigmented ink ribbon plates and to print a monochrome digital image on the surface of the plastic card using black pigmented ink ribbon plates to create a combined image on the surface. In addition, the plastic card printing mechanism can be configured to print the color digital image and the monochrome digital image on the transferable print-receptive layer of the retransfer material to produce a combined image, and thereafter transfer the transferable print-receptive layer containing the combined image to the surface of the plastic card. Further, the source digital image may include two or more of a background image, a card issuer name, a card issuer identification, a personal account number, a cardholder name, an expiration date, a payment network name, and a payment network identification. Further, the plastic card may include a financial card having at least one of a magnetic stripe and an integrated circuit chip. Further, the controller may be configured to scan each pixel in the source digital image to detect a monochrome pixel. For each detected monochrome pixel, the controller may be configured to determine whether there is a neighboring color pixel. If there are neighboring color pixels, the controller may be configured to add the detected monochrome pixels to the color digital image. If there are no neighboring color pixels, the controller may be configured to change the detected monochrome pixel to a white pixel. Further, the controller may be configured to scan each pixel in the source digital image to detect color pixels. For each detected color pixel, the controller may be configured to determine whether there is a neighboring monochrome pixel. If there is a neighboring monochrome pixel, the controller may be configured to change the detected color pixel to a monochrome pixel and add the monochrome pixel to the monochrome digital image.

In yet another embodiment, a plastic card handling mechanism is disclosed. The plastic card handling mechanism may include the plastic card printing mechanism of the above-described embodiment. The plastic card handling mechanism may further comprise at least one of the following: a lamination mechanism, an integrated circuit chip programming mechanism, a magnetic stripe read/write mechanism, an embossing mechanism, an indent printing mechanism, a card cleaning mechanism, a laser mechanism, or a card ejection mechanism.

The techniques described herein may be implemented in any type of plastic card printing mechanism that utilizes CMYK printing. The plastic card printing mechanism may be used in a desktop plastic card printer that has a small footprint intended to allow the desktop plastic card printer to reside on a desktop, and is designed to personalize plastic cards in small quantities (e.g., hundreds or thousands per hour). An example of a desktop plastic card printer is a CD800 card printer available from Entrust Datacard corporation of sekko lute, minnesota. Additional examples of desktop printers are disclosed in U.S. Pat. Nos. 7,434,728 and 7,398,972, each of which is incorporated herein by reference in its entirety. The plastic card printing mechanism may also be part of a high volume plastic card production machine (typically configured with multiple processing stations or modules, often referred to as a central issuing system) that processes multiple plastic cards simultaneously and is designed to personalize the plastic cards in large quantities (e.g., thousands of cards per hour). Examples of central distribution systems are the MX or MPR series of central distribution systems available from Entrust Datacard company of sekko lute, minnesota. Additional examples of centrally issued systems are disclosed in U.S. patents 4,825,054, 5,266,781, 6,783,067, and 6,902,107, all of which are incorporated herein by reference in their entirety. In some embodiments, the card printer (desktop or central issuing) may include a mechanism to read and/or write data to a magnetic stripe and/or to program an integrated circuit chip on the card.

Drawings

FIG. 1A represents a source digital image containing gray and color pixels represented by cells as described herein;

FIG. 1B shows a source digital image containing gray and color regions as described herein;

FIG. 1C shows the generated color digital image from FIG. 1A, wherein all gray pixels of the source digital image of FIG. 1A are extracted using the pixel extraction process described herein;

FIG. 1D shows the generated color digital image from FIG. 1B, wherein all gray pixels of the source digital image of FIG. 1B are extracted using the pixel extraction process described herein;

FIG. 1E shows the generated monochromatic digital image from FIG. 1A, in which all of the color pixels of the source digital image of FIG. 1A are extracted using the pixel extraction process described herein;

FIG. 1F shows the generated monochromatic digital image from FIG. 1B, in which all of the color pixels of the source digital image of FIG. 1B have been extracted using the pixel extraction process described herein;

FIG. 2A shows a source digital image with registration deviation to demonstrate the need for print trapping;

FIG. 2B is an enlarged view of a portion of FIG. 2A to better illustrate registration deviation;

FIG. 2C illustrates the generation of a color image (represented by cells) with a print trap applied as described herein;

FIG. 2D illustrates the generation of a color digital image (based on the source digital image of FIG. 2A) with a print trap applied as described herein;

FIG. 2E shows a final printed image based on the generated color digital image of FIG. 2D and the generated monochrome digital image based on the source digital image of FIG. 2A, with a print trap applied as described herein;

FIG. 2F is an enlarged view of a portion of FIG. 2E;

FIG. 2G illustrates the generation of a monochrome digital image (represented by cells) with a print trap applied as described herein;

FIG. 3A illustrates the concept of pixel expansion for use in printing trapping as described herein;

FIG. 3B illustrates an example of a possible pixel evaluation order in a print trap as described herein;

FIG. 3C shows an example of the possible sequential pixel evaluation order of FIG. 3B;

FIG. 3D shows yet another example of the possible sequential pixel evaluation order of FIG. 3C;

FIG. 4A illustrates a printed color image with no print trapping applied as described herein;

FIG. 4B shows a printed color image similar to FIG. 4A, but wherein the print trapping application described herein;

FIG. 4C shows a printed color image similar to FIG. 4A, but wherein the printing trapping and linear hybrid application described herein;

FIG. 5 shows a flow chart depicting the steps of generating a color digital image from a source digital image;

FIG. 6 shows a flow chart depicting the steps of generating a monochrome digital image from a source digital image;

FIG. 7 illustrates a portion of a plastic card printing mechanism for use in a plastic card handling mechanism.

Like reference numerals refer to like parts throughout.

Detailed Description

The following describes techniques for printing, for example, a bright gray color on plastic cards, such as financial (e.g., credit, debit, etc.) cards, drivers' licenses, national identification cards, commercial identification cards, gift cards, and other plastic or composite cards that carry personalization data unique to or specifically assigned to the cardholder and/or carry other card information. As used herein, the term "plastic card" encompasses cards that are completely or substantially plastic, and cards that have non-plastic or composite components, as well as cards that have other formulations that function as the type of card indicated above. The cards covered by the term "plastic cards" typically carry printed personalization data unique to or specifically assigned to the cardholder, such as the cardholder's name, account, facial image of the cardholder, and the like.

The following features may be implemented to achieve a bright gray color printed on a plastic card. These features may be used individually or in any combination thereof. These features include: 1) use of CMYK pigment inks to achieve CMYK printing; 2) a pixel extraction process and/or a print trapping process; 3) two independent print commands, including a CMY (or CMYK) + blend print command and a K + blend print command; and 4) appropriate card settings.

CMYK printing

Traditionally, there are two main types of inks used for printing on plastic cards:

a. dye ink: the dye ink interacts with the plastic card surface by penetrating into the plastic material and is completely absorbed into the card surface. In plastic card printing, the dye ink is typically not dithered when printed because the print head has fine control over the amount of dye transferred to directly produce tens of different shades.

b. Pigment ink: the pigment ink adheres to the top surface of the card and is located on top of the plastic material. Printing with pigment ink print heads is generally possible to produce only a few different dot sizes on the card surface, which results in very few shades of each color. Thus, in plastic card printing, the use of pigment inks typically requires that the printed image be dithered (e.g., with clustered dot dithering) to obtain an acceptable number of different shades of each color on the card surface.

Dye inks are typically only the three primary print colors (C, M, Y) because K dye inks cannot achieve the required density to produce a good black on plastic card substrates. Therefore, plastic card printing mechanisms that utilize dye inks must utilize pigment inks for their K inks. Color printing on plastic cards with dyes cannot use black for true CMYK printing (where the K pigment ink is used to blend with C, M and the Y pigment ink in the printed image) because the appearance of the dithered pigment K ink on top of the card surface appears very different from the non-dithered pigmented dye CMY ink (which adsorbs into the card surface). Dye inks are limited to CMY printing for the color portion of the card image, and K-pigment ink printing for any black personalization data and black bar codes.

To achieve a bright gray color on a plastic card as described above, CMYK pigment inks are used to create CMYK prints on the plastic card. In one embodiment, the CMYK prints may include CMY + K prints. In such embodiments, the color image is presented in CMY (where K is not mixed), and the monochrome image is presented in K. In another embodiment, the CMYK prints may include CMYK + K prints. In such embodiments, the color image is presented in CMYK (to support, for example, a real CMYK print, where K is mixed), and the monochrome image is presented in another K (e.g., another K color band). All four CMYK pigment inks have similar properties that allow the production of high quality color images on plastic cards. The CMYK pigment inks can be provided on a common ink ribbon with the pigment inks disposed on a carrier, wherein the CMYK pigment inks are arranged in a repeating discrete sequence, thereby alternating the CMYK panel, as is well known in the art. In another embodiment, the CMYK pigmented inks can each be provided on their own ink ribbon (i.e., C, M, Y, and K ribbons), with the plastic card being transported sequentially through each ink ribbon for printing of each CMYK color. In addition, some plates may contain additional or special colorant materials (which are non-CMYK pigmented inks). Examples of additional or special colorant materials include, but are not limited to, silver colorant materials and/or gold colorant materials. Further, in some embodiments, some of the plates may be plates of phosphor material used to print the phosphor material. The fluorescent material (if used) is typically transparent to allow viewing of the print that may ultimately underlie the fluorescent material. Further, the print ribbon may include additional panels, such as panels of overlapping material, in each sequence. It is to be understood that laser and/or inkjet (e.g., drop-on-demand) printing can be used to print the pigment in addition to the ribbon.

Pixel extraction and/or print trapping

Two separate data processing techniques may be performed on the source digital image to improve the resulting printed image on the plastic card. One data processing technique will be referred to herein as pixel extraction. Another data processing technique will be referred to herein as print trapping. In some embodiments, pixel extraction and print trapping may be used together. In other embodiments, only pixel extraction may be used without print trapping. In other embodiments, only print trapping may be used without pixel extraction.

Pixel extraction is the process of scanning a source image for the purpose of generating two different images (a color image to be rendered in CMY or CMYK, for example, and a monochrome image to be rendered in a monochrome band (e.g., black, gold, silver, etc.). All pixels of the source image are scanned (or detected) to determine the pixels that should be copied (rendered) onto the color image and the pixels that should be copied (rendered) onto the monochrome image. The use of a single color band and the pointing to a particular pixel to be rendered by the single color band may provide the ability to apply a spot color (particular pixel) anywhere on the final printed image. In the following description of the method and system, examples of gray pixel extraction and spot colors are used to illustrate the concept. It should be understood that the techniques described herein may be applicable to any other spot color (specific pixel), such as gold and silver.

For gray pixel extraction directed to the black monochromatic color band, two images are generated: color images and monochrome images, the color images containing all colored (i.e., non-gray) pixels of the source image, with gray pixels extracted (e.g., filled with white pixels); the monochrome image contains all gray pixels of the source image, with all color pixels extracted (e.g., filled with white pixels). Pixel extraction may allow for proper control and cost savings of printing gray pixels by controlling the process with black (K) as compared to using a corresponding amount of coloring ink (e.g., CMY or CMYK).

In one embodiment, a source image for printing is scanned pixel-by-pixel. The source image includes a front card image and a back card image for a plastic card printer. The source image may be a composite image that includes all relevant text (e.g., personal account, customer name, etc.), customer photograph, and/or background image. The source image may be a source digital image. Each pixel of the source image may be represented as a 24-bit RGB or 32-bit alpha RGB pixel, and so on. It should be understood that 8-bit and/or 64-bit RGB (or alpha RGB) source images may also be used. A scan source image may be defined as processing digital data of a digital source image pixel by pixel. Color images and monochrome images can be generated by a scanning process. The generated color image may include all colored (i.e., non-gray) pixels of the source image, with all gray pixels of the source image being extracted (i.e., filled with white pixels). The generated color image may be a 24-bit RGB or 32-bit alpha RGB image (same as the source image). The generated monochrome image may contain all gray pixels of the source image, wherein all color pixels of the source image are extracted (i.e., filled with white pixels). The generated monochrome image may be an 8-bit (256 grayscale pixels) monochrome image.

In an embodiment, each of the color image and the monochrome image may start with an image having the same size as the source image, but filling all white pixels. In another embodiment, each of the color image and the monochrome image may start with a null image. During the scanning process, the source image is scanned pixel-by-pixel. Typically, a pixel is defined by its RGB value (or ARGB value for alpha RGB). An embodiment using gray pixel extraction is described here as an example. In such embodiments, if the RGB values of the pixels of the source image are determined to be completely or substantially equal (e.g., R ═ l00, G ═ l00, B ═ l00), then the pixels are determined/defined to be gray (i.e., monochrome) pixels. The gray pixels of the source image are added (or copied) to the monochrome image at equivalent coordinates with respect to the source image. In a color image, the equivalent coordinates for the gray pixels of the source image contain the initially filled white pixels. If the RGB values of the pixels of the source image are determined to be not substantially equal at all (e.g., R-l 0, G-l 00, B-255), then the pixels are determined/defined to be non-gray pixels (i.e., color pixels). According to such a definition, a white pixel (R-255, G-255, B-255) is a gray pixel, a black pixel (R-0, G-0, B-0) is a gray pixel, and any pixel other than the gray pixel is a color pixel. It should be understood that in some embodiments, white pixels are referred to as white pixels (see, e.g., fig. 5 and 6), although they are considered gray pixels by definition. It should also be understood that the definition of gray pixels is used to describe embodiments of gray pixel extraction.

If the pixels of the source image are color pixels, then the color pixels are added (or copied) to the color image at equivalent coordinates with respect to the source image. In a monochrome image, the equivalent coordinates for the color pixels of the source image contain the initially filled white pixels.

The pixel extraction process described above can be a necessary step because it allows the rendering of gray pixels with K pigment and color pixels with CMY pigment, a color image (including all color pixels) can be printed with CMY (or CMYK) pigment, and a monochrome image (including all gray pixels) can be printed with K pigment.

In one embodiment, the above definition of a gray pixel (i.e., if the RGB values of a pixel are determined to be completely or substantially identical (e.g., R ═ l00, G ═ l00, B ═ l00), then the pixel is defined as a gray pixel) may be inadequate because there are many colors that appear gray to the eye, but where the RGB values are not equal. These colors are defined as perceived gray. For example, a pixel having RGB values (R ═ l00, G ═ 99, and B ═ l0 l). Depending on the background image (e.g., a monochrome image) of the plastic card, there may be large areas of perceived gray that ultimately appear on the color image due to the above definition of gray pixels. To compensate for this strict definition, the gray scale change values are used in the definition of gray scale pixels. The gray scale variation values provide a certain tolerance to be considered gray during the pixel scanning process of the source image when generating color and/or monochrome images.

In one embodiment, a formula is used to calculate the gray scale change value. The formula calculates the midpoint between the maximum and minimum of the three RGB values (which is the gray scale variation value). The midpoint is then compared to a threshold configured by the user during print setup. If the midpoint is below or equal to the threshold, the pixel is considered a gray pixel and added to the monochrome image. If the mid-point is above the threshold, the pixel is considered a color pixel and added to the color image. This formula can be expressed in pseudo-code as:

MIN (R, G, B)

MAX (R, G, B)

Midpoint (max-min)/2

IsGrey ═ threshold (midpoint < ═ threshold)

For example, for a pixel having RGB values (R ═ l00, G ═ 99, B ═ l0l) and the threshold is set to 1, the minimum value MIN (R, G, B) ═ MIN (100,99,101) ═ 99, the maximum value MAX (R, G, B) ═ MAC (100,99,101) ═ 101, the midpoint (i.e., gray scale change value) — (MAX-minimum)/2 ═ 101-99)/2 ═ 1, the equation "midpoint (which is 1) < ═ threshold (which is 1 in this example)" is true, and IsGrey is true. Thus, pixels of the source image having RGB values (R ═ l00, G ═ 99, B ═ l0l) are considered gray pixels and added to the monochrome image.

It should be appreciated that the near gray color pixels in the above example (perceptual gray pixels where IsGrey is true) must be converted to gray (i.e., gray pixels where the RGB values are all equal) before they can be added to the monochrome image. There are a number of ways for the conversion and the user is provided with a number of configurable options. In the above example, the RGB values of a near-gray color pixel may be converted to all minimum values (R-99, G-99, B-99), all maximum values (R-l 0l, G-l 0l, B-l 0l), or to intermediate values, such as (R-l 00, G-l 00, B-l 00).

For another example, for a pixel having RGB values (R99, G96, B l00) and the threshold is set to 1, MIN (R, G, B) MIN (99,96,100) 96, MAX (R, G, B) MAX (99,96, l00) 100, midpoint (i.e., gray-level change value) MAX (99,96, l00) 100, 2 (100-96)/2, equation "midpoint (which is 2) <threshold (which is 1 in this example)" is false, and grey is false. Thus, pixels of the source image having RGB values (R99, G96, B l00) are considered as color pixels and added to the color image.

When performing multi-color printing on substrates such as plastic cards, passport pages, and retransfer films, a printhead having a multi-color printing ribbon may be used. The multi-color print ribbon may include a plurality of CMYK panels. A controller is operably coupled to the print head to control operation of the print head. In one embodiment, the scanning process may be performed by a controller. The scanning process can generate a color image equivalent to the source image in which all gray pixels are extracted (e.g., filled with white pixels), and a monochrome image equivalent to the source image in which all color pixels are extracted (e.g., filled with white pixels). In one embodiment, the controller sends the generated color image and the generated monochrome image to the plastic card printer through two separate function calls to specify the ribbon plate (CMY for color images, or K for monochrome images) to be used for image rendering.

Fig. 1A shows a source image containing gray and color pixels represented by cells. As shown in fig. 1A, the source image is represented by 5 × 5 cells. Each cell represents a pixel. Solid shaded cells 700 represent gray pixels. Grid shaded cells 705 represent color pixels. FIG. 1B shows a source image containing gray and color regions. In FIG. 1B, the oval indicia 710 is colored and the other areas (such as the background 715 and the text "Plastic Card" 720) are white, gray, or black.

Fig. 1C shows the generated color image, where all gray pixels of the source image in fig. 1A are extracted. In FIG. 1C, cell 725 is white. Grid shaded cells 730 represent color pixels. FIG. 1D shows a generated color image in which all gray pixels of the source image in FIG. 1B have been extracted. In FIG. 1D, the oval indicia 710 is colored and the text 720 is white.

FIG. 1E shows a generated monochrome image in which all color pixels of the source image of FIG. 1A have been extracted. In fig. 1E, the solid shaded cells 735 represent gray pixels. Cell 740 is white. FIG. 1F shows a generated monochrome image in which all color pixels of the source image in FIG. 1B have been extracted. In fig. 1B, the oval logo is extracted (shown in white as 745) and other areas (such as background 715 and text 720) are white, gray, or black.

Print trapping can be defined as a process that produces a pixel overlap between a color image and a monochrome image that allows some variation in printer registration and avoids gaps between CMY and K regions. When generating color and monochrome images, the pixels of the color and monochrome images are aligned such that each pixel has non-white RGB values in one image or the other, but not both images. In this case, a slight misalignment (misregistration) may result in the generation of a region through which the card substrate appears.

In color printing, registration generally refers to a method of correlating overlapping colors on a single image. When printing images having more than one color, it is necessary to print each color separately and to ensure that each color accurately overlaps the other colors. Otherwise, the finished image will appear distorted, blurred, or "misaligned". To facilitate correct color alignment, a registration system is necessary. There may be different categories and types of registration, and multiple registrations may employ alignment of specific markers. In practice, however, minor registration deviations of the printer ribbon plate may still exist. Figure 2A shows a source image with registration deviation. In fig. 2A, the background 210 is black, the rightmost vertical bar 200 and the bottom horizontal bar 205 are gray, and the remaining vertical and horizontal bars are a different color (shown as black and/or gray) and are misaligned at the edges of the vertical/horizontal bars (see also fig. 2B). Fig. 2B is an enlarged view of a portion of fig. 2A. In fig. 2B, the background 210 is black, the rightmost vertical bar 200 is gray, and the remaining vertical and horizontal bars are a different color (shown as black and/or gray). The edges 202 of the vertical color bars and the edges 204 of the horizontal color bars show that the edges of the vertical/horizontal color bars are blurred (misaligned).

Thus, when printing generated color and monochrome images, there may be constraints due to the requirement for perfect registration of the pixels of the printer ribbon and the application of CMY and K plates. To compensate for minor registration deviations of the printer ribbon plate, the technique of printing trapping can be applied to color and/or monochrome images.

In one embodiment, each of the detected gray pixels of the source image is also evaluated or examined during the scanning of the source image. If there are neighboring color pixels in the source image for a gray pixel, then this gray pixel is added to the color image at equivalent coordinates with respect to the source image. If there are no neighboring color pixels in the source image for the gray pixels, then no action is required (i.e., the gray pixels are extracted from the color image).

Similarly, during scanning of the source image, each of the detected colored (non-gray) pixels of the source image is also evaluated or examined. If there is an adjacent gray pixel to the color pixel in the source image, then the color pixel is replaced with a gray pixel (or converted to a gray pixel) and added to the monochrome image at equivalent coordinates with respect to the source image. If there are no adjacent gray pixels for a color pixel in the source image, then no action need be taken (i.e., extracting the color pixel from the monochrome image).

In such embodiments, the process of inspecting adjacent color/gray pixels and adding gray pixels to the color and/or monochrome image (in the case where adjacent color/gray pixels are found) is defined as print trapping. Print trapping can produce pixel overlap between color and monochrome images that allows some variation in printer registration and avoids gaps between CMY and K regions. The methods and systems described herein scan all pixels in a source color image and detect neighboring pixels to determine if print trapping should occur.

Fig. 2C shows a color image (represented by cells) generated by printing trapping. In fig. 2C, cell 215 is white. Those gray pixels 225 (represented by solid shading) having neighboring color pixels in the source image are added to the color image at equivalent coordinates with respect to the source image. Grid shaded cells 220 represent color pixels. Fig. 2D shows a generated color image (based on the source image of fig. 2A) by printing a trap. All of the vertical bars 230 and horizontal bars 235 in fig. 2D are of different colors (shown as black and/or gray). FIG. 2E shows the final print result of the generated monochrome image based on the generated color image of FIG. 2D and based on the source image of FIG. 2A. In fig. 2E, the background 240 is black, the rightmost vertical bar 245 and the bottom horizontal bar 250 are gray, and the remaining vertical and horizontal bars are a different color (shown as black and/or gray). Fig. 2F is an enlarged view of a portion of fig. 2E. In fig. 2F, the background 240 is black, the rightmost vertical bar 245 and the bottom horizontal bar 250 are gray, and the remaining vertical and horizontal bars are a different color (shown as black and/or gray).

FIG. 2G illustrates a monochrome image (represented by cells) generated by print trapping according to one embodiment. In fig. 2G, cell 270 is white. Cell 260 (with solid shading) is a gray pixel. Those color pixels in the source image that have adjacent gray pixels (at the location of cell 265) are replaced with gray pixels 265 (or converted with gray pixels and a gradient is applied, which is described in the following section) and added to the monochrome image at equivalent coordinates with respect to the source image. The gray pixels with the applied gradient are represented by cells 265 with downward diagonal shading.

With print trapping, color and monochrome images have overlapping pixels. Overlapping pixels may allow for minor registration deviations and avoid areas of the card substrate appearing therethrough.

As shown in fig. 2G, those color pixels in the source image that have adjacent gray pixels (at the location of cell 265) are replaced with gray pixels 265 that have an applied gradient and added to the monochrome image. In addition to the gradient, some other parameters may be used when performing print trapping. Parameters of print trapping include (1) the direction in which the pixel spread is applied, (2) the depth at which the pixel spread is expected, and/or (3) the need to apply a gradient to spread the pixel, which fades gradually from the color/monochrome edge to white.

In print trapping, when an adjacent color/gray pixel is found, the gray pixel is added to the other (gray/color) extraction area in the color and/or monochrome image. This process of adding gray pixels (when neighboring color/gray pixels are found) can be defined as pixel spreading. The pixel extension may have a direction and a depth. As shown in fig. 2C, the pixel expands to the left direction. In fig. 2G, the pixel expands to the right direction. In fig. 2C and 2G, the depth of the pixel extension (which is described in the following section) is one. During print setup, the user can select the direction in which the pixels will expand to other (gray/color) extraction areas and the depth of the pixel expansion.

FIG. 3A illustrates a direction for detecting neighboring pixels, according to one embodiment. As shown in fig. 3A, 5 × 5 cells represent four different directions for detecting adjacent pixels (details will be described later, see fig. 5 and 6). The intermediate pixels 320 are control pixels (shown in white for demonstration only) and represent the pixels that are evaluated for print trapping (i.e., whether the control pixels are to be presented on a color or monochrome image). For example, if the middle pixel 320 is a gray pixel, then the neighboring pixels are examined to determine if there are neighboring color pixels. The actual pixel cell detected is determined according to the desired pixel extension direction. The horizontally shaded cells 300 (4 at the top) represent the adjacent pixels above the control pixel, and the downward direction of pixel spreading is available when the adjacent pixels are not pointing to the same color or monochrome image (e.g., the control pixel is a gray pixel and the adjacent pixels are color pixels). Similarly, cells 305 with vertical shading (4 at the bottom) represent the upward direction of pixel spread. Cells 315 with grid shading (7 at the left) represent the right direction of pixel spread. Cells 370 with diagonal shading up (7 at the right) represent the left direction of pixel expansion.

During the process of scanning the source image and generating the color image, when a gray pixel of the source image is detected during the scanning process, color pixels (which may be control pixels as shown in fig. 3A) within one or more of the four directions (up, down, left, and/or right, which may be selected in a print setting) of the detected gray pixel are searched. If a color pixel is found in one or more predetermined directions, a gray pixel (control pixel) is added to the color image at equivalent coordinates with respect to the source image. If no color pixels are found in one or more predetermined directions, no action is required. The direction of pixel spread may provide the ability to constrain the print trapping to a particular direction (or directions).

Similarly, during the process of scanning a source image and generating a monochrome image, when a color pixel of the source image is detected during the scanning process, gray pixels (which can be control pixels as shown in fig. 3A) within one or more of the four directions (up, down, left, and/or right, which can be selected in a printing setting) of the detected color pixel are searched. If a gray pixel is found in one or more predetermined directions, then the color pixels (control pixels) are replaced with (or converted to) gray pixels and added to the monochrome image at equivalent coordinates with respect to the source image. If no gray pixels are found in one or more predetermined directions, no action is required.

It should be understood that print trapping can be applied to only color images, only monochrome images, or both color and monochrome images. The user may configure options during print setup.

FIG. 3B illustrates a pixel extension of depth one, according to one embodiment. As shown in FIG. 3B, pixel extensions in any particular direction (up, down, left, and/or right) have a depth of one. The depth of pixel expansion is defined as how many levels neighboring pixels of the middle control pixel 325 are examined in a particular direction. For example, as shown in fig. 3B, in the upward direction for detecting the adjacent pixel (i.e., the downward direction in which the pixel expands), the pixel of one level is checked against the intermediate collation pixel 325. The total pixels examined at one level (in the upward direction for examining neighboring pixels) are one (labeled as "1" in fig. 3B). Similarly, in the downward direction for checking the adjacent pixel (i.e., the upward direction in which the pixel expands), one level of pixels is checked against the intermediate collation pixel 325. The total pixels examined at one level (in the downward direction for examining neighboring pixels) are one (labeled "5" in fig. 3B). In the leftward direction for checking the neighboring pixels (i.e., the rightward direction in which the pixels spread), the pixels of one level are checked with respect to the middle collation pixel 325. The total pixels examined at one level (in the leftward direction for examining the adjacent pixels) are three (labeled "6", "7", and "8" in fig. 3B). In the right direction for checking the neighboring pixels (i.e., the left direction in which the pixels spread), one level of pixels is checked against the middle collation pixel 325. The total pixels examined at one level (in the rightward direction for examining the neighboring pixels) are three (labeled as "2", "3", and "4" in fig. 3B). The user can configure the depth of the pixel extension in the print setup.

FIG. 3C illustrates a pixel extension of depth two according to one embodiment. As shown in fig. 3C, pixel extensions in any particular direction (up, down, left, and/or right) have a depth of two. For example, as shown in fig. 3C, in the upward direction for checking the adjacent pixels, two levels of pixels are checked with respect to the middle collation pixel 330. The total pixels examined at two levels (in the upward direction for examining adjacent pixels) are four (labeled "1", "9", "10", and "11" in fig. 3C). Similarly, in the downward direction for checking the neighboring pixels, two levels of pixels are checked against the middle control pixel 330. The total pixels examined at two levels (in the downward direction for examining adjacent pixels) are four (labeled "5", "15", "16", and "17" in fig. 3C). In the leftward direction for checking the neighboring pixels, two levels of pixels are checked with respect to the middle collation pixel 330. The total pixels examined at two levels (in the leftward direction for examining adjacent pixels) is six (labeled "6", "7", "8", "18", "19", and "20" in fig. 3C). In the right direction for checking the neighboring pixels, two levels of pixels are checked with respect to the middle collation pixel 330. The total pixels examined at two levels (in the rightward direction for examining adjacent pixels) is six (labeled as "2", "3", "4", "12", "13", and "14" in fig. 3C).

FIG. 3D illustrates a pixel extension of depth three, according to one embodiment. As shown in fig. 3D, pixel extensions in any particular direction (up, down, left, and/or right) have a depth of three. For example, as shown in fig. 3D, in the upward direction for checking the adjacent pixels, three levels of pixels are checked against the middle collation pixel 335. The total pixels inspected at three levels (in the upward direction for inspecting neighboring pixels) are nine (labeled as "1", "9" to "11", and "21" to "25" in fig. 3D). Similarly, in the downward direction for examining adjacent pixels, three levels of pixels are examined relative to the middle cross-pixel 335. The total pixels examined at three levels (in the downward direction for examining neighboring pixels) are nine (labeled "5", "15" to "17" and "33" to "37" in fig. 3D). In the leftward direction for checking the neighboring pixels, three levels of pixels are checked against the middle cross pixel 335. The total pixels examined at three levels (in the leftward direction for examining adjacent pixels) are thirteen (labeled "6" to "8", "18" to "20", and "38" to "44" in fig. 3D). In the right direction for checking the neighboring pixels, three levels of pixels are checked against the middle cross pixel 335. The total pixels examined at three levels (in the rightward direction for examining neighboring pixels) are thirteen (labeled "2" to "4", "12" to "14", and "26" to "32" in fig. 3D).

During the process of scanning a source image and generating a color image and/or a monochrome image, the methods and systems described herein can evaluate the control pixel (for gray pixels of a color image, and for color pixels of a monochrome image) and the search pixel under examination for neighboring pixels within a predetermined direction and depth of expansion. The search order of neighboring pixels is represented by the value of the cell (e.g., 1 to 44 in fig. 3D) and depends on the quadrant/direction and depth of pixel expansion in which the print setup is configured to detect. For example, if only the "upward" direction (or the "downward" direction of pixel expansion) for checking the neighboring pixels is configured to detect the neighboring pixels and the depth of pixel expansion is configured to be three, the neighboring pixels "1", "9" to "11" and "21" to "25" of the checked control pixel are checked.

It should be understood that the number of neighboring pixels to be checked when the depth of pixel extension is configured to be greater than one is increased compared to the number of neighboring pixels to be checked when the depth of pixel extension is configured to be one. The greater the depth, the greater the number of adjacent pixels to be examined. To simplify the inspection process when the depth of pixel expansion is configured to be greater than one, the inspection process may stop if it is determined that the intermediate control pixel is surrounded by all white pixels, the control pixel not being added as a gray pixel to the color image or monochrome image.

The generated color image contains all the color pixels of the source image and the gray pixels added from the print trapping process. The monochrome image contains all the gray pixels of the source image and the gray pixels added from the print trapping process. All remaining pixels (achromatic or grey) of the corresponding color or monochrome image are represented as white pixels.

The gray pixels (i.e., extended pixels) added to the color image and/or monochrome image during print trapping can apply gradients (otherwise known as trapping gradients). As the extended pixel moves further away from the color/monochrome edge, the applied gradient may gradually fade the extended pixel toward white. For an example in which a gradient is applied to the extended pixels, see fig. 2G. The user can configure the trapping gradient in the print setup.

Applying a gradient to and extending a pixel during a print trap may be defined as blending. Blending can mitigate the effects of print trapping by reducing the visibility of the overlap region between the color image and the monochrome image.

As previously discussed, printing a trap may produce pixel overlap between regions of a color image and a monochrome image. The overlap area may be evident on a printed plastic card. For example, during a print trapping process on a color image, gray pixels of the source image having adjacent pixels (in one or more predetermined pixel expansion directions, and within a predetermined pixel expansion depth) are added to the color image. When generating a monochrome image, all gray pixels of the source image are added to the monochrome image. Therefore, in the overlap region, the gray pixels are on both the color image and the monochrome image. When CMYK printing is performed, a color image represents all pixels of the color image (including gray pixels resulting from print trapping) with CMY, and a monochrome image represents all pixels of the monochrome image with K. Drawing the same pixel twice (i.e., overlapping gray pixels) may result in an overall darker area on the printed plastic card, and the overlapping area may be noticeable.

The methods and systems described herein may apply mixing during a print trapping process. During the print trapping process on a color image, a user-configurable gradient may be applied to gray pixels (which have adjacent color pixels in the source image) before adding the gray pixels to the color image. Similarly, during a print trapping process on a monochrome image, a user-configurable gradient can be applied to color pixels (which have adjacent gray pixels in the source image) before the color pixels are converted to gray pixels and/or the converted gray pixels are added to the monochrome image. Applying a gradient to a gray pixel transitions the RGB values of the gray pixel towards white (R255, G255, B255).

For a configured pixel extension depth (e.g., a depth of 5), different gradients may be applied to the extended gray pixels of different depths (or levels) on the color image only, the monochrome image only, or both the color and monochrome images. Different gradients applied to gray pixels can cause different degrees of transition of the RGB values of the gray pixels towards white. In one embodiment, different gradients may be applied so that the RGB values of gray pixels from depth 1 to depth 5 may gradually transition to white. The user may configure the blend to set a linear transition towards white, a "faster" transition, or a "slower" transition. In one embodiment, the mixing option may also be disabled.

Fig. 4A shows a color image generated without print trapping. The generated color image contains only color pixels 400 (shown as black and/or gray). Fig. 4B shows the color image of fig. 4A with print trapping and pixel spread of depth 5, shown as black and/or gray. In fig. 4B, 400 denotes a color pixel, and 405 denotes an extension pixel. Fig. 4C shows the color image of fig. 4A with print trapping, linear mixing, and pixel expansion of depth 5, shown as black and/or gray. In fig. 4C, 400 denotes a color pixel, and 410 denotes an extended pixel with linear mixing.

It should be appreciated that print trapping is required due to inherent registration deviations when applying the presented image to the card substrate. The degree of registration deviation may not necessarily be fixed (or constant) between presses or jobs. In one embodiment, print trapping can create an overlap region to account for the worst registration deviation case. In such embodiments, print trapping may produce more overlap area than desired, and mixing may help to mitigate this effect.

In operation, the generated color and monochrome images (e.g., after pixel extraction, perceptual gray inspection, print trapping, and/or blending) are sent by, for example, a controller to a plastic card printer through two separate function calls to specify a color ribbon plate for image rendering (CMY for color images including any extended gray pixels, or K for monochrome images).

It should be appreciated that there may be alternative methods to implement the print trapping and/or mixing process. For example, there may be alternative algorithms for checking neighboring pixels. Regions of a source image may be scanned multiple times to identify pixel formations and trapping regions. For another example, there may be alternative formulas for gray scale change values and color to gray conversion. For yet another example, there may be alternative ways to delineate the gray pixel trapping/overlapping regions on a color image. Intermediate color pixels (rather than compound gray) may be used for print trapping on the color image.

Fig. 5 shows a schematic diagram of a color image generated based on a source image. The process described in the schematic of fig. 5 may be performed, for example, by a controller. The process in fig. 5 is based on similar or identical processes discussed in previous sections. The source image is the image that the user will print on the plastic card. The methods and systems described herein may implement a print job by generating a color image and a monochrome image based on a source image, printing with CMYK, printing the color image with CMY plates, and printing the monochrome image with K plates.

In one embodiment, the color image may start with a null image (e.g., having a size of 0). When generating a color image, the source image is scanned pixel by pixel. At 510, each pixel of the source image is evaluated based on, for example, the RGB values of the pixel. At 515, if the pixel under evaluation is determined to be a color pixel or a white pixel, then the process proceeds to 520. At 520, the process delineates the pixels in the color image at equivalent coordinates with respect to the source image.

It should be understood that when generating a color image, an image having the same dimensions as the source image but filled with all white pixels may be generated as a color image in one embodiment. Then, during the scanning of the source image, the colored pixels of the source image can be drawn (or added/copied) in the color image at equivalent coordinates with respect to the source image (to replace the pre-filled white pixels). In such embodiments, because the color image has been pre-filled with white pixels, no action need be taken if there is a need to add white pixels to the color image.

At 515, if the pixel under evaluation is neither a color pixel nor a white pixel, then the process proceeds to 525. At 525, the print trapping configuration is checked. If the print trapping function is not enabled, the process proceeds to 535. At 535, the white pixels are rendered in the color image at equivalent coordinates (pixels being evaluated) with respect to the source image. If the print trapping function is enabled, the process proceeds to 530.

At 530, neighboring color pixels of the pixel being evaluated are searched. The current pixel extension depth of the search is n (starting at 1). It should be understood that the user may define the direction of pixel expansion. The process then proceeds to 540.

At 540, if a neighboring (i.e., adjacent) color pixel (of the pixel under evaluation) is found at the pixel extension depth n, then the process proceeds to 550 or optionally to 545. At 550, the process delineates the pixel (being evaluated) in a color image at equivalent coordinates with respect to the source image. At 545, blending is applied to the pixels being evaluated. The process then proceeds to 550.

At 540, if no neighboring (i.e., adjacent) color pixels (of the pixel being evaluated) are found at the pixel extension depth n, then the process proceeds to 555. At 555, if all surrounding pixels (of the pixel being evaluated) are determined to be white, then the process proceeds to 565. At 565, white pixels are rendered in the color image at equivalent coordinates (of the pixel being evaluated) with respect to the source image.

At 555, if it is determined that not all surrounding pixels (of the pixel under evaluation) are white, then the process proceeds to 560. At 560, n is increased by 1. The process then proceeds to 570. At 570, if the current pixel extension depth n exceeds the configured maximum pixel extension depth, then the process proceeds to 565. At 570, if the current pixel extension depth n is equal to or less than the configured maximum pixel extension depth, then the process returns to 540.

After 520, 535, 550 or 565, the action is completed for the current pixel (the pixel being evaluated) and the process moves to the next pixel of the source image and repeats the process described by the schematic of FIG. 5.

FIG. 6 shows a schematic diagram of generating a monochrome image based on a source image. The process described in the schematic of fig. 6 may be performed, for example, by a controller. The process in fig. 6 is based on similar or identical processes discussed in previous sections. The source image is the image that the user will print on the plastic card. The methods and systems described herein may implement a print job by generating a color image and a monochrome image based on a source image, printing with CMYK, printing the color image with CMY plates, and printing the monochrome image with K plates.

In one embodiment, the monochrome image may start with an empty image (i.e., having a size of 0). When generating a monochrome image, the source image is scanned pixel by pixel. At 610, each pixel of the source image is evaluated based on, for example, the RGB values of the pixel. At 615, if the pixel under evaluation is determined to be a gray pixel or a white pixel, then the process proceeds to 620. At 620, the process draws the pixels in a monochromatic image at equivalent coordinates with respect to the source image.

It should be appreciated that when generating a monochrome image, an image having the same size as the source image but filled with all white pixels can be generated as a monochrome image in one embodiment. Then, during scanning of the source image, the gray pixels of the source image can be traced (or added/copied) in the monochromatic image at equivalent coordinates with respect to the source image (to replace the pre-filled white pixels). In such embodiments, because the monochrome image has been pre-populated with white pixels, if there is a need to add white pixels to the monochrome image, then no action need be taken.

At 615, if the pixel being evaluated is neither a gray pixel nor a white pixel, then the process proceeds to 680. At 680, the gray change check configuration is checked. If gray scale change checking is enabled, the process proceeds to 685. At 685, if the pixel under evaluation is perceived gray, then the pixel under evaluation is converted to a gray pixel and the process proceeds to 620. At 620, the process delineates the transformed pixels in a monochromatic image at equivalent coordinates with respect to the source image.

At 685, if the pixel being evaluated is not perceptually gray, then the process proceeds to 625. At 680, if the gray change check is not enabled, then the process also proceeds to 625. At 625, the print trapping configuration is checked. If the print trapping function is not enabled, the process proceeds to 635. At 635, the white pixels are rendered in a monochromatic image at equivalent coordinates (pixels under evaluation) with respect to the source image. If the print trapping function is enabled, the process proceeds to 630.

At 630, the neighboring gray pixels for which the evaluation pixel is made are searched. The current pixel extension depth of the search is n (starting at 1). It should be understood that the user may define the direction of pixel expansion. The process then proceeds to 640.

At 640, if a neighboring (i.e., adjacent) gray pixel (of the pixel under evaluation) is found at the pixel extension depth n, then the process proceeds to 650 or optionally to 645. If 645 is not performed, then at 650 the pixel being evaluated is converted to a gray pixel and the process draws the converted pixel in a monochrome image at equivalent coordinates with respect to the source image. At 645, the pixel being evaluated is converted to a gray pixel and blending is applied to the converted pixel. The process then proceeds to 650. If 645, then the process draws the converted pixels in a monochrome image at equivalent coordinates with respect to the source image at 650.

At 640, if no neighboring (i.e., adjacent) gray pixels (of the pixel under evaluation) are found at the pixel extension depth n, then the process proceeds to 655. At 655, if it is determined that all surrounding pixels (of the pixel under evaluation) are white, then the process proceeds to 665. At 665, the white pixels are rendered in the monochrome image at equivalent coordinates (of the pixel being evaluated) with respect to the source image.

At 655, if it is determined that not all surrounding pixels (of the pixel under evaluation) are white, then the process proceeds to 660. At 660, n is increased by 1. The process then proceeds to 670. At 670, if the current pixel extension depth n exceeds the configured maximum pixel extension depth, then the process proceeds to 665. At 670, if the current pixel extension depth n is equal to or less than the configured maximum pixel extension depth, then the process returns to 640.

After 620, 635, 650 or 665, the action is completed for the current pixel (the pixel being evaluated) and the process moves to the next pixel of the source image and repeats the process described by the schematic of FIG. 6.

Print order

The source image is typically a composite image that includes all relevant text (e.g., personal account, customer name, etc.), customer photograph, and background image. Processing the source image (e.g., by pixel extraction, print trapping, and/or blending processes) may result in a color digital image and a monochrome digital image. The color digital image and the monochrome digital image can be sent to the plastic card printing mechanism via two separate function calls to specify the ribbon plate to be used for image rendering (e.g., one function call for CMY for color images and a second function call for K for monochrome images). The function call for the color image may include all color pixels of the source image, with gray pixels extracted, extension pixels (by print trapping) and/or blend (CMY + blend) applied to the extension pixels. The function call for a monochrome image may include all gray pixels of the source image, with color pixel extraction, extended pixels (by print trapping) and/or blending (K + blending) applied to the extended pixels.

Card arrangement

A user may configure printing settings for printing plastic cards via, for example, a Graphical User Interface (GUI). The user may configure the print settings using appropriate aliasing (aliasing), layering, saturation, and/or desaturation. In one embodiment, the user may set the printed colored text or color indicia to be aliased. The user may also place the served original image in multiple layers. For example, bank logos, identifiers, and/or text may be on a different layer than a gray/black background image. The background image/layer (i.e., printed with only K-plates) may be configured to be desaturated. It should be understood that saturation is typically used to describe the intensity of a color in an image. Saturated images typically have too bright a color. Aliasing, layering, and saturation/desaturation are well known techniques for card printing in the field of card placement.

It should also be understood that the processing operations performed on the plastic card may include one or more of the following: multi-color printing, monochrome printing, laminating one or more sides of a card, encoding a magnetic strip on a card, programming of an integrated circuit chip embedded in a card, embossing, dent printing, card cleaning, laser printing, card debossing, and the like.

FIG. 7 illustrates a portion of a plastic card printing mechanism 100 for use in a plastic card processing mechanism, and the techniques described herein may be implemented on the plastic card printing mechanism 100 to print brilliant gray cards. The printing mechanism 100 is shown as performing retransfer printing. However, the printing mechanism 100 may be configured to perform direct to card printing as well.

The specific construction and operation of a retransfer printer (including printing a ribbon, retransfer film, printing an image onto a retransfer film, and transferring the printed image onto the surface of a card) is well known in the art. An example of retransfer printing is disclosed in U.S. patent 6,894,710 et al. U.S. patent 6,894,710 is incorporated herein by reference in its entirety. The illustrated retransfer printing arrangement of the printing mechanism 100 includes a printing side including a print ribbon supply 102 (from which a supply of print ribbon 104 is supplied) and a print ribbon take-up 106 (which takes up used print ribbon 104). The print ribbon is guided through a print head 108, which print head 108 may be stationary in the example shown, and performs printing on a retransfer film 110 with the print ribbon 104. After printing, the used printing ribbon 104 is then wound onto a take-up 106.

The retransfer film 110 is supplied from a film supply section 112 on the retransfer side, and after retransfer, the remaining film 110 is wound onto a film take-up section 114 also on the retransfer side. The retransfer film 110 is directed through a platen roller 116, the platen roller 116 being positioned opposite the print head 108 and movable toward and away from the print head 108 in the illustrated example to press the retransfer film 110 and the print ribbon 104 between the print head 108 and the platen roller 116 during printing on the retransfer film 110. The retransfer film 110 can be any retransfer film 110 having one or more layers of transferable material that can be transferred from the retransfer film 110 onto a plastic card substrate.

The section of retransfer film 110 with the printed image is then advanced to a transfer station 120 where the intermediate retransfer material bearing the printed image is transferred onto the surface of a card 122. In this example, the transfer station 120 includes a heated transfer mechanism 124 (e.g., a transfer roller), the heated transfer mechanism 124 being movable toward and away from a stationary platen 126 located on an opposite side of the card travel or transport path. The heated transfer mechanism 124 presses the portion of the retransfer film 110 containing the printed image against the card 122, the card 122 resting against the platen 126, wherein the retransfer film 110 and card 122 are then conveyed together past the heated transfer mechanism 124 to transfer one or more layers of transferable material of the retransfer film 110 containing the printed image onto the card surface. The retransfer film 110 and card 122 are then conveyed to a peeling station 128, where one or more layers of transferable material of the retransfer film 110 are peeled away from the card 122, leaving the retransfer material bearing the printed image on the card 122. The remaining portion of the transferred material subtracted from the retransfer film 110 is then wound onto a film take-up 114. The card 122 is conveyed along the card travel path by a card conveyance mechanism known in the art, such as a plurality of sets of rollers.

The controller 130 controls the operation of the printing mechanism 100. In one embodiment, controller 130 may implement the pixel extraction process and/or the print trapping process described above, and may generate and send CMY + hybrid print commands and K + hybrid print commands to printing mechanism 100. The controller 130 may also control the card settings described above.

The presently disclosed examples are to be considered in all respects as illustrative and not restrictive. The scope of the invention is indicated by the appended claims (rather than the foregoing description); and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.

The terminology used in the description is for the purpose of describing particular embodiments and is not intended to be limiting. The terms "a", "an" and "the" also include the plural forms unless expressly specified otherwise. The terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, and/or components.

With reference to the foregoing description, it will be understood that changes may be made in detail, especially in matters of shape, size, and arrangement of parts and materials of construction employed, without departing from the scope of the present disclosure. The word "embodiment" as used in this specification may, but does not necessarily, refer to the same embodiment. This description and the described embodiments are only examples. Other and further embodiments may be devised without departing from the basic scope thereof, and the true scope and spirit of the present disclosure is indicated by the claims that follow.