阅读说明：本技术 画像校正方法、图像形成装置及存储介质 (Image correction method, image forming apparatus, and storage medium ) 是由 马杨晓 于 2021-08-02 设计创作，主要内容包括：本申请实施例提供一种画像校正方法、图像形成装置及存储介质,所述方法包括沿待校正方向获取校正参考图像的第一端颜色密度值和/或第二端颜色密度值；将所述第一端颜色密度值和/或所述第二端颜色密度值与目标颜色密度值进行差值计算,获得第一端颜色密度差值和/或第二端颜色密度差值；若所述第一端颜色密度差值和/或所述第二端颜色密度差值大于或等于预设的差值阈值,则对待校正图像进行均一性校正。采用本申请实施例提供的方案,可以对均一性较差的图像形成装置进行均一性校正,使得该图像形成装置打印的图像具有较好的均一性效果。另外,本申请实施例提供的校正方案可以避免多次测量或校正影响打印效率,节省了测量时间和成本。(The embodiment of the application provides an portrait correcting method, an image forming device and a storage medium, wherein the portrait correcting method comprises the steps of obtaining a first end color density value and/or a second end color density value of a corrected reference image along a direction to be corrected; performing difference calculation on the first end color density value and/or the second end color density value and a target color density value to obtain a first end color density difference value and/or a second end color density difference value; and if the first end color density difference value and/or the second end color density difference value are/is larger than or equal to a preset difference threshold value, performing uniformity correction on the image to be corrected. By adopting the scheme provided by the embodiment of the application, the uniformity of the image forming device with poor uniformity can be corrected, so that the image printed by the image forming device has a good uniformity effect. In addition, the correction scheme provided by the embodiment of the application can avoid the influence of multiple times of measurement or correction on the printing efficiency, and saves the measurement time and cost.)

1. An image correction method, comprising:

acquiring a first end color density value and/or a second end color density value of the corrected reference image along the direction to be corrected;

performing difference calculation on the first end color density value and/or the second end color density value and a target color density value to obtain a first end color density difference value and/or a second end color density difference value;

and if the first end color density difference value and/or the second end color density difference value are/is larger than or equal to a preset difference threshold value, performing uniformity correction on the image to be corrected.

2. The method according to claim 1, wherein the performing uniformity correction on the image to be corrected comprises:

calculating a compensation color density value of the image to be corrected by interpolation fitting by taking a reference axis of the image to be corrected as a standard position, wherein the reference axis is vertical to the direction to be corrected;

and fusing the original dot matrix image of the image to be corrected with the compensation dot matrix image corresponding to the compensation color density value to obtain a corrected image.

3. The method according to claim 2, wherein before the fusing the original dot matrix image of the image to be corrected with the compensated dot matrix image corresponding to the compensated color density value to obtain the corrected image, the method further comprises:

converting the compensated color density values to corresponding pixel grayscale values;

converting the pixel gray value into corresponding grating dot matrix data;

and determining whether the image to be corrected needs to be subjected to uniformity correction processing according to the black point distribution characteristics of the grating dot matrix data.

4. The method of claim 3, wherein converting the compensated color density values to corresponding pixel grayscale values comprises:

and mapping the compensation color density value to a corresponding pixel gray value according to a mapping table.

5. The method of claim 3, wherein converting the pixel gray scale values into corresponding raster dot matrix data comprises:

and converting the pixel gray value into corresponding raster dot matrix data according to the halftone matrix table.

6. The method of claim 5, wherein converting the pixel gray scale values to corresponding raster dot matrix data according to a halftone matrix table comprises:

and converting the pixel gray value into corresponding grating dot matrix data in the same binary rasterization mode according to the halftone matrix table of each color channel.

7. The method of claim 1,

the target color density value is a preset color density value matched with the correction reference image; alternatively, the first and second electrodes may be,

the target color density value is an average of the first end color density value and the second end color density value.

8. The method according to claim 1, wherein the corrected reference image comprises a first patch group and a second patch group which are symmetrically arranged with respect to a reference axis of the corrected reference image, wherein pixel values of mutually symmetric patches in the first patch group and the second patch group are the same, and the reference axis is perpendicular to the direction to be corrected.

9. The method according to claim 8, wherein the first patch group and the second patch group respectively include two or more patches whose pixel values are different.

10. The method according to claim 1, wherein before the obtaining of the first end color density value and/or the second end color density value of the corrected reference image along the direction to be corrected, further comprises:

printing the corrected reference image.

11. The method according to claim 1, wherein the direction to be corrected is a horizontal direction and/or a vertical direction of a printed page.

12. An image forming apparatus, comprising:

a processor;

a memory;

the memory has stored therein a computer program that, when executed, causes the image forming apparatus to perform the method of any of claims 1-11.

13. A computer-readable storage medium, comprising a stored program, wherein the program, when executed, controls an apparatus on which the computer-readable storage medium resides to perform the method of any one of claims 1-11.

Technical Field

The present invention relates to the field of image forming technology, and more particularly, to an image correction method, an image forming apparatus, and a storage medium.

Background

An image forming apparatus is a device that forms an image on a recording medium by the principle of image formation, such as a printer, a copying machine, a facsimile machine, a multifunction image making and copying apparatus, an electrostatic printing apparatus, and any other similar apparatus.

The photosensitive assembly is one of the most important components in the developing and imaging process of the image forming device. A common photosensitive assembly includes a photosensitive drum, the surface of which is coated with a photosensitive material, and when a Laser Scanning Unit (LSU for short) irradiates the surface of the photosensitive drum, the resistance of the irradiated portion becomes small, and the electric charge disappears; while the portions not irradiated by the laser scanning unit still retain electric charges. Finally, the surface of the photosensitive drum forms an electrostatic latent image composed of electric charges. When the charged surface of the photosensitive drum passes through the developing assembly, the developing roller sends a developer such as carbon powder for forming a visible image to the electrostatic latent image on the surface of the photosensitive drum in cooperation with an acting force such as an electric field force, so that the electrostatic latent image is visualized.

However, when the image forming apparatus is used for a long period of time, there is a problem that image formation is not uniform due to aging of the photosensitive drum or the like. For example, the image uniformity in the horizontal direction is poor because the left and right images are shallow and the middle image is deep. Of course, there may be problems with poor uniformity in other directions, such as the vertical direction.

Disclosure of Invention

The embodiment of the application provides an image correction method, an image forming device and a storage medium, which are beneficial to solving the problem of poor imaging uniformity in the prior art. Of course, there may be problems with poor uniformity in other directions, such as the vertical direction.

In a first aspect, an embodiment of the present application provides an image correction method, including:

acquiring a first end color density value and/or a second end color density value of the corrected reference image along the direction to be corrected;

performing difference calculation on the first end color density value and/or the second end color density value and a target color density value to obtain a first end color density difference value and/or a second end color density difference value;

and if the first end color density difference value and/or the second end color density difference value are/is larger than or equal to a preset difference threshold value, performing uniformity correction on the image to be corrected.

Preferably, the performing uniformity correction on the image to be corrected includes:

calculating a compensation color density value of the image to be corrected by interpolation fitting by taking a reference axis of the image to be corrected as a standard position, wherein the reference axis is vertical to the direction to be corrected;

and fusing the original dot matrix image of the image to be corrected with the compensation dot matrix image corresponding to the compensation color density value to obtain a corrected image.

Preferably, before the fusing the original dot matrix image of the image to be corrected and the compensation dot matrix image corresponding to the compensation color density value to obtain the corrected image, the method further includes:

converting the compensated color density values to corresponding pixel grayscale values;

converting the pixel gray value into corresponding grating dot matrix data;

and determining whether the image to be corrected needs to be subjected to uniformity correction processing according to the black point distribution characteristics of the grating dot matrix data.

Preferably, the converting the compensated color density value into a corresponding pixel gray value includes:

and mapping the compensation color density value to a corresponding pixel gray value according to a mapping table.

Preferably, the converting the pixel gray scale value into corresponding raster dot matrix data includes:

and converting the pixel gray value into corresponding raster dot matrix data according to the halftone matrix table.

Preferably, the converting the pixel gray scale value into corresponding raster dot matrix data according to a halftone matrix table includes:

and converting the pixel gray value into corresponding grating dot matrix data in the same binary rasterization mode according to the halftone matrix table of each color channel.

Preferably, the target color density value is a preset color density value matched with the corrected reference image; alternatively, the first and second electrodes may be,

the target color density value is an average of the first end color density value and the second end color density value.

Preferably, the calibration reference image includes a first color block set and a second color block set symmetrically with respect to a reference axis of the calibration reference image, pixel values of color blocks in the first color block set and pixel values of color blocks in the second color block set that are symmetric to each other are the same, and the reference axis is perpendicular to the direction to be calibrated.

Preferably, the first color patch group and the second color patch group respectively include two or more color patches, and the pixel values of the two or more color patches are different.

Preferably, before the obtaining of the first end color density value and/or the second end color density value of the corrected reference image along the direction to be corrected, the method further includes:

printing the corrected reference image.

Preferably, the direction to be corrected is a horizontal direction and/or a vertical direction of the printed page.

In a second aspect, an embodiment of the present application provides an image forming apparatus including:

a processor;

a memory;

the memory has stored therein a computer program that, when executed, causes the image forming apparatus to perform the method of any of the first aspects.

In a third aspect, an embodiment of the present application provides a computer-readable storage medium, where the computer-readable storage medium includes a stored program, where the program, when executed, controls an apparatus in which the computer-readable storage medium is located to perform the method according to any one of the first aspects.

By adopting the scheme provided by the embodiment of the application, the uniformity of the image forming device with poor uniformity can be corrected, so that the image printed by the image forming device has a good uniformity effect. In addition, the correction scheme provided by the embodiment of the application can avoid the influence of multiple times of measurement or correction on the printing efficiency, and saves the measurement time and cost.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive labor.

Fig. 1 is a schematic view of an application scenario provided in an embodiment of the present application;

fig. 2A is a schematic diagram of an image to be corrected according to an embodiment of the present disclosure;

FIG. 2B is a schematic diagram of a color density curve according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of an image correction method according to an embodiment of the present application;

FIG. 4 is a schematic diagram of a corrected reference image according to an embodiment of the present disclosure;

FIG. 5A is a schematic view of another color density curve provided in the examples of the present application;

FIG. 5B is a graph of a uniformity corrected image according to an embodiment of the present disclosure;

FIG. 5C is a schematic view of another color density curve provided in the examples of the present application;

fig. 6A is a schematic diagram of an image to be corrected according to an embodiment of the present disclosure;

FIG. 6B is a schematic view of another color density curve provided in the embodiments of the present application;

FIG. 6C is a schematic diagram of the image shown in FIG. 6A after uniformity correction;

fig. 7 is a schematic structural diagram of an image processing apparatus according to an embodiment of the present application.

Detailed Description

For better understanding of the technical solutions of the present application, the following detailed descriptions of the embodiments of the present application are provided with reference to the accompanying drawings.

It should be understood that the embodiments described are only a few embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The terminology used in the embodiments of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the examples of this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be understood that the term "and/or" as used herein is merely one type of associative relationship that describes an associated object, meaning that three types of relationships may exist, e.g., A and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

Referring to fig. 1, a schematic view of an application scenario provided in the embodiment of the present application is shown. Fig. 1 shows an image forming apparatus 100, and an image correction method provided in an embodiment of the present application is applicable to the image forming apparatus 100. It is to be understood that fig. 1 is only an exemplary illustration, and the embodiment of the present application does not limit the specific form of the image forming apparatus 100. For example, the image forming apparatus 100 includes, but is not limited to, a printer, a copier, a facsimile machine, a scanner, a multi-function peripheral that performs the above functions in a single device, and the like.

In practical applications, when the image forming apparatus is used for a long period of time, the problem of non-uniform image formation may occur due to aging of the photosensitive drum and the like.

Referring to fig. 2A, a schematic diagram of an image to be corrected according to an embodiment of the present application is provided. As shown in FIG. 2A, the left and right images of the image to be corrected are shallow, and the middle image is darker.

Referring to fig. 2B, a schematic diagram of a color density curve provided in the embodiment of the present application is shown. The color density curve is the color density curve of the image shown in fig. 2A, and is used for reflecting the color density variation of the image in the horizontal direction. As can be seen from the color density curve, the color density values are higher and the middle color density value is lower on the left and right sides of the image.

Therefore, as can be seen from fig. 2A and 2B, the image to be corrected is poor in uniformity in the horizontal direction.

It will be appreciated that there may be problems of poor uniformity in other directions than the horizontal direction, such as the vertical direction.

Based on this, embodiments of the present application provide an image correction method, an image forming apparatus, and a storage medium, so as to solve the problem of poor imaging uniformity in the prior art. The following detailed description is made with reference to the accompanying drawings.

FIG. 3 is a schematic diagram of an image correction method according to an embodiment of the present disclosure. The method is applicable to the image forming apparatus shown in fig. 1, and mainly includes the following steps, as shown in fig. 3.

Step S301: and acquiring a first end color density value and/or a second end color density value of the corrected reference image along the direction to be corrected.

The direction to be corrected according to the embodiment of the application is the direction in which uniformity correction is required in a printed page. For example, the direction to be corrected may be a horizontal direction or a vertical direction of the printed page, and may also be other directions of the printed page, which is not particularly limited in the embodiment of the present application.

In a specific implementation, a correction reference image may be printed by the image forming apparatus to be corrected so as to correct the image forming apparatus to be corrected based on the correction reference image.

In some possible implementations, the correction reference image may be a halftone image, where halftone refers to a picture tone in which a tone value is expressed by a dot size or a density. Corresponding to the halftone is a continuous tone. The continuous tone image is usually on one image, the tone change from light to dark or from light to dark is formed by the density of the imaging substance particles in unit area, and the depth and the shade of the continuous tone image are in stepless change, such as photo negative, photo and various sketches; the halftone usually means that the tone change from light to dark or from light to dark on the printed matter after special processing is represented by the size of the dots, and since the dots are distributed discretely in a certain distance in space and the number of levels of screening is always limited, the halftone image is called a halftone image because the gradation change of the image cannot be realized like a continuous tone image.

The color density can reflect the depth of the image, if the difference between the color density values at the two ends of the direction to be corrected and the target color density value is large, which indicates that the uniformity of the direction to be corrected is poor, the uniformity of the image forming device in the direction to be corrected needs to be corrected; on the contrary, if the difference between the color density values at the two ends of the direction to be corrected and the target color density value is small, which indicates that the uniformity of the direction to be corrected is good, the uniformity correction of the image forming apparatus in the direction to be corrected is not needed. Therefore, the color density values at two ends of the direction to be corrected in the corrected reference image need to be obtained in the embodiment of the present application, and for convenience of description, the color density values at two ends of the direction to be corrected in the embodiment of the present application are respectively referred to as a first end color density value and a second end color density value.

It is noted that in some possible implementations, the first end color density value and the second end color density value may each comprise a set of data. For example, the color density values of the first end and the second end respectively comprise N, wherein N is more than or equal to 2.

For example, when the direction to be corrected is the horizontal direction, the first end color density value and the second end color density value are the left end color density value and the right end color density value of the correction reference image, respectively. In a specific implementation, the left-end color density value and the right-end color density value may respectively include a set of data, that is, N left-end color density values and N right-end color density values. Wherein, the ith Left end color Density value is expressed as Density _ Left [ i ]; the ith Right-hand color Density value is expressed as Density _ Right [ i ].

In some possible implementations, the correction reference image includes a first color block set and a second color block set symmetrically arranged with respect to a reference axis of the correction reference image, pixel values of color blocks in the first color block set and pixel values of color blocks in the second color block set that are symmetric to each other are the same, and the reference axis is perpendicular to the direction to be corrected.

As indicated above, the first end color density value and the second end color density value may each comprise a set of data, i.e., N first end color density values and N second end color density values, respectively, where N ≧ 2. Correspondingly, the first color block group and the second color block group respectively comprise N color blocks, so that N first end color density values are obtained according to the N color blocks in the first color block group; and obtaining N second end color density values according to the N color blocks in the second color block group. In some possible implementations, the pixel values of the N color patches are different. For example, the pixel values of the N color patches vary uniformly between 0-255. Of course, those skilled in the art may set the pixel values of the N color blocks in other ways, which is not limited in this application.

Referring to fig. 4, a schematic diagram of a corrected reference image according to an embodiment of the present application is shown. The correction direction corresponding to the corrected reference image shown in fig. 4 is the horizontal direction, and the corrected reference image includes two color patch groups, i.e., a first color patch group and a second color patch group, which are arranged symmetrically.

Specifically, the first color patch group and the second color patch group respectively include 9 color patches, and RGB values of the 9 color patches are (0, 0, 0) (32, 32, 32) (64, 64, 64) (96, 96) (128, 128, 128) (160, 160, 160) (192, 192, 192) (224, 224, 224) (255, 255, 255) from top to bottom.

In the embodiment of the present application, the first color block group and the second color block group are symmetrically arranged, which means that positions of color blocks in the first color block group and the second color block group are symmetrically arranged, and RGB values of the color blocks that are symmetrical to each other are the same. For example, in the corrected reference image shown in fig. 4, the RGB values of the left and right color blocks in the first row are both (0, 0, 0), and the RGB values of the left and right color blocks in the second row are both (32, 32, 32), and so on, which is not described again in this embodiment of the application.

Specifically, the left-end color density value and the right-end color density value obtained from the corrected reference image shown in fig. 4 are shown in table one.

Table one:

wherein, the left end color density value corresponding to the color block in the 1 st row is 1.08, and the right end color density value is 1.11; the left end color density value corresponding to the 2 nd row color block is 0.84, and the right end color density value is 0.96, and the like. And will not be described in detail herein.

It should be noted that the corrected reference image shown in fig. 4 is only one possible implementation and should not be taken as a limitation to the scope of the present application. For example, a person skilled in the art may set more than two color patches (e.g., 3 or 4) in each row according to actual needs, and only take the color density values of the color patches at the left and right ends when determining whether correction is needed; of course, whether correction is needed or not can be determined according to the color density values of the more than two color blocks, which is not specifically limited by the embodiment of the present application.

Step S302: and performing difference calculation on the first end color density value and/or the second end color density value and a target color density value to obtain a first end color density difference value and/or a second end color density difference value.

In one possible implementation, the target color density value may be a preset color density value that matches the corrected reference image; alternatively, the target color density value is an average of the first end color density value and the second end color density value. In specific implementation, the image forming apparatus with normal correction and normal uniformity may be used to collect the color density values of the color patches in the correction reference image, obtain the color density values of the color patches, and calculate the target color density value according to the average value of the first end color density value and the second end color density value. This is not particularly limited by the examples of the present application.

As indicated above, the first end color density value and the second end color density value may each comprise a set of data, including N first end color density values and N second end color density values, where N ≧ 2. Accordingly, the target color density value also comprises a set of data, i.e. comprising N target color density values.

Referring to table two, the target color density value corresponding to the corrected reference image shown in fig. 4 provided in the embodiment of the present application is shown in table two, and the target color density value includes 9 data, which respectively correspond to each row of color blocks in fig. 4, that is, each row of color blocks corresponds to one target color density value. For example, the target color density value for the row 1 patch is 1.12, the target color density value for the row 2 patch is 0.98, and so on.

Table two:

for ease of illustration, the ith target color Density value is denoted as Density _ Center [ i ]. In the specific implementation, the N first end color density values and/or the N second end color density values are respectively subjected to difference calculation with the N target color density values to obtain N first end color density differences and/or N second end color density differences, wherein N is greater than or equal to 2.

And if the direction to be corrected is the horizontal direction, respectively carrying out difference calculation on the left end color density value and/or the right end color density value and the target color density value to obtain a left end color density difference value and/or a right end color density difference value. The specific calculation formula is as follows:

the formula I is as follows: delta Density _ CL [ i ] -Density _ Center [ i ] -Density _ Left [ i ]

The formula II is as follows: delta Density _ CR [ i ] -Density _ Center [ i ]

Wherein, DeltaDensity _ CL [ i ] represents the ith left end color density value, and DeltaDensity _ CR [ i ] represents the ith right end color density value.

In one possible implementation, the left-end color density value and the right-end color density value shown in table one are respectively subjected to difference calculation with the target color density value shown in table two to obtain a left-end color density difference value and a right-end color density interpolation value, as shown in table three.

Table three:

wherein, the left end color density difference value corresponding to the color block of the 1 st row is 0.04, and the right end color density difference value is 0.01; the color density difference of the left end corresponding to the color block of the 2 nd row is 0.14, the color density difference of the right end corresponding to the color block of the 2 nd row is 0.02 and the like. And will not be described in detail herein.

Step S303: and if the first end color density difference value and/or the second end color density difference value are/is larger than or equal to a preset difference threshold value, performing uniformity correction on the image to be corrected.

The image to be corrected according to the embodiment of the present application may be understood as an image printed by the image forming apparatus to be corrected.

In a specific implementation, a difference threshold is set in the embodiment of the present application, so that the first end color density difference and/or the second end color density difference obtained in step S302 are respectively compared with the difference threshold to determine whether uniformity correction is required. If the first end color density difference value and/or the second end color density difference value are/is larger than or equal to a preset difference threshold value, the uniformity of the corrected reference image is poor, namely the uniformity of the corresponding image forming device is poor, and the uniformity correction needs to be carried out on the image forming device; on the contrary, if the first end color density difference value and/or the second end color density difference value is smaller than the preset difference threshold value, the uniformity of the corrected reference image is better, that is, the uniformity of the corresponding image forming apparatus is better, and the uniformity correction of the image forming apparatus is not needed.

In a possible implementation manner, if the first end color density difference or the second end color density difference is greater than or equal to a preset difference threshold, performing uniformity correction on the image to be corrected. That is, as long as the color density difference value at one end is greater than or equal to a preset difference threshold value, uniformity correction is performed.

A person skilled in the art can set the difference threshold corresponding to the size according to actual needs, which is not described in this embodiment of the present application again.

In some possible implementations, the performing uniformity correction on the image to be corrected specifically includes: calculating a compensation color density value of the image to be corrected by interpolation fitting by taking a reference axis of the image to be corrected as a standard position, wherein the reference axis is perpendicular to the direction to be corrected, preferably, the reference axis can be a perpendicular bisector of a page width, and the page width can be understood as a page direction corresponding to the direction to be corrected; and fusing the original dot matrix image of the image to be corrected with the compensation dot matrix image corresponding to the compensation color density value to obtain a corrected image.

Referring to table four, the compensated color density values within the page width are calculated for an interpolation fitting provided by the embodiment of the present application. Which corresponds to the embodiment shown in fig. 4, the page width corresponds to the horizontal direction.

Table four:

LeftN

Left…

Left3

Left2

Left1

Left0

Center

Right0

Right1

Right2

Right3

Right…

RightN

BN

B...

B3

B2

B1

B0

Target

A0

A1

A2

A3

A...

AN

wherein, AN is a compensation color Density value corresponding to Density _ Right, BN is a compensation color Density value corresponding to Density _ Left, and Target is a compensation color Density value corresponding to Density _ Center.

Referring to fig. 5A, another color density curve is provided for the embodiments of the present application. Fig. 5A shows an image color density curve to be corrected and a compensation color density curve. The color density curve of the image to be corrected corresponds to the color density curve shown in fig. 2B, and the complementary color density curve is a color density curve corresponding to the compensation dot matrix image.

After the compensation dot matrix image corresponding to the compensation color density curve shown in fig. 5A is fused with the original dot matrix image shown in fig. 2A, an image with corrected uniformity is obtained.

Referring to fig. 5B, a uniformity corrected image is provided according to an embodiment of the present application. The image after the uniformity correction is an image obtained by performing the uniformity correction on the image shown in fig. 2A, and as shown in fig. 5B, the image after the uniformity correction has a good effect of uniformity of depth of the image in the horizontal direction.

Referring to fig. 5C, another color density curve is provided for the embodiments of the present application. Fig. 5C is different from fig. 5A in that a uniformity-corrected color density curve, which is a color density curve of the image shown in fig. 5B, is added to reflect the color density variation of the image after uniformity correction in the horizontal direction. As can be seen from the uniformity-corrected color density curve, the uniformity effect of the color density value in the horizontal direction is good. In a possible implementation manner, in order to further improve the accuracy of the image correction, after obtaining the compensation color density value, whether the uniformity correction needs to be further confirmed according to the compensation color density value.

Specifically, before the uniformity correction is performed, the compensation color density value is converted into a corresponding pixel gray scale value, and specifically, the compensation color density value may be converted into a corresponding pixel gray scale value by means of table look-up mapping. Then, the pixel gray value is converted into corresponding raster dot matrix data, and specifically, the pixel gray value can be converted into corresponding raster dot matrix data through the same binary rasterization mode according to the halftone matrix table of each color channel. And finally, determining whether the image to be corrected needs to be subjected to uniformity correction processing according to the black point distribution characteristics of the grating dot matrix data. In this way it is again verified whether a uniformity correction is necessary. The distribution characteristics of the black spots mainly refer to the presentation effects of different carbon powders and different imaging systems on 0/1 dot matrix images, and the effects have certain tolerance, namely, human eyes cannot distinguish the images even if the images are different within a certain range; beyond this range, the human eye can distinguish, in which case corrections are needed.

If the uniformity correction is determined to be necessary in the above mode, performing uniformity correction on the image to be corrected; otherwise, uniformity correction is not performed.

Referring to fig. 6A, a schematic diagram of an image to be corrected according to an embodiment of the present application is provided. As shown in fig. 6A, the image to be corrected is poor in uniformity in the page width direction, and therefore, the image needs to be corrected in uniformity in the page width direction.

Referring to fig. 6B, another color density curve diagram is provided for the embodiments of the present application. The abscissa represents RGB data corresponding to the corrected reference image, and the ordinate represents the color density value. Curve DL represents the left color density curve detected from the calibration reference image; the curve DR represents a right color density curve obtained from the calibration reference image detection; the curve Refer represents the desired standard color density curve; the Curve represents a compensated color density Curve calculated from the corrected reference image.

Fig. 6C is a schematic diagram of the image shown in fig. 6A after uniformity correction. Specifically, the image shown in fig. 6A may be subjected to uniformity correction based on the compensated color density curve shown in fig. 6B. As shown in fig. 6C, after the uniformity correction is performed, the image has good uniformity of depth in the page width direction.

By adopting the scheme provided by the embodiment of the application, the uniformity of the image forming device with poor uniformity can be corrected, so that the image printed by the image forming device has a good uniformity effect. In addition, the correction scheme provided by the embodiment of the application can avoid the influence of multiple times of measurement or correction on the printing efficiency, and saves the measurement time and cost.

Corresponding to the method embodiment, the application also provides an image processing device.

Referring to fig. 7, for a schematic structural diagram of an image processing apparatus provided in an embodiment of the present application, the image processing apparatus 700 may include: a processor 701, a memory 702, and a communication unit 703. The components communicate over one or more buses, and those skilled in the art will appreciate that the configuration of the servers shown in the figures are not meant to limit embodiments of the present invention, and may be in the form of buses, stars, more or fewer components than those shown, some components in combination, or a different arrangement of components.

The communication unit 703 is configured to establish a communication channel, so that the storage device can communicate with other devices. Receiving the user data sent by other devices or sending the user data to other devices.

The processor 701, which is a control center of the storage device, connects various parts of the entire system using various interfaces and lines, and performs various functions of the system and/or processes data by operating or executing software programs and/or modules stored in the memory 702 and calling data stored in the memory. The processor may be composed of Integrated Circuits (ICs), for example, a single packaged IC, or a plurality of packaged ICs connected to the same or different functions.

The memory 702 is used for storing instructions executed by the processor 701, and the memory 702 may be implemented by any type of volatile or non-volatile storage device or combination thereof, such as Static Random Access Memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk.

The execution instructions in the memory 702, when executed by the processor 701, enable the image processing apparatus 700 to perform some or all of the steps of the image processing apparatus side in the above-described method embodiments.

In particular implementations, the present application also provides a computer readable storage medium, where the computer readable storage medium may store a program, and the program may include some or all of the steps in the embodiments provided in the present application when executed. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), a Random Access Memory (RAM), or the like.

In a specific implementation, an embodiment of the present application further provides a computer program product, where the computer program product includes executable instructions, and when the executable instructions are executed on a computer, the computer is caused to perform some or all of the steps in the foregoing method embodiment.

In the embodiments of the present application, "at least one" means one or more, "a plurality" means two or more. "and/or" describes the association relationship of the associated objects, and means that there may be three relationships, for example, a and/or B, and may mean that a exists alone, a and B exist simultaneously, and B exists alone. Wherein A and B can be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. "at least one of the following" and similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, at least one of a, b, and c may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple.

Those of ordinary skill in the art will appreciate that the various elements and algorithm steps described in connection with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or combinations of electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

The above description is only for the specific embodiments of the present application, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present disclosure, and all the changes or substitutions should be covered by the protection scope of the present application. The protection scope of the present application shall be subject to the protection scope of the claims.