Apparatus and method for fluorescence grading of gemstones
阅读说明：本技术 用于宝石的荧光分级的设备和方法 (Apparatus and method for fluorescence grading of gemstones ) 是由 H·塔卡什 于 2016-03-30 设计创作，主要内容包括：本发明名称为用于宝石的荧光分级的设备和方法。本文提供一种用于评估宝石的荧光特性的设备。设备包括：不透光平台,用于支撑待评估宝石；一个或多个光源,用以提供均匀UV照明和非UV照明；影像捕获组件；和远心透镜,其经定位以将照明宝石的荧光影像提供至影像捕获组件。也提供基于使用此设备所收集的影像的荧光分析的方法。(The invention relates to an apparatus and method for fluorescence grading of gemstones. An apparatus for assessing fluorescence properties of a gemstone is provided herein. The apparatus comprises: a light-tight platform for supporting a gemstone to be assessed; one or more light sources to provide uniform UV illumination and non-UV illumination; an image capture component; and a telecentric lens positioned to provide the fluorescence image of the illuminated gemstone to the image capture assembly. Methods of fluorescence analysis based on images collected using the apparatus are also provided.)
1. A method of evaluating fluorescence properties of a sample gemstone, comprising:
(i) determining a fluorescence mask for a fluorescence image in a plurality of fluorescence images based on a contour mask determined from an image in the plurality of images and an apparent fluorescence area based on the fluorescence image, wherein each image in the plurality of images comprises a full image of the sample gemstone illuminated by a non-UV light source, wherein each image in the plurality of fluorescence images comprises a full image of the sample gemstone illuminated by a uniform UV light source, and wherein the image and the fluorescence image are captured under the same conditions except for the illumination light source;
(ii) quantifying individual color components in each pixel in the fluorescence mask in the fluorescence image of the plurality of fluorescence images, thereby converting values of individual color components into one or more parameters representing the color characteristics of each pixel;
(iii) determining an average value for each of the one or more parameters for all pixels in a defined region in all images of the plurality of fluorescent images; and
(iv) calculating a first fluorescence score for a sample gemstone based on the average of the one or more parameters for all pixels in the defined region in all images of the plurality of fluorescence images.
2. The method of claim 1, further comprising:
(v) calculating a second fluorescence score for the sample gemstone based on pixels in the contour mask for all of the plurality of fluorescence images.
3. The method of claim 2, further comprising:
(vi) evaluating the fluorescence characteristic of the sample gemstone by comparing the value of the first fluorescence score or the second fluorescence score to the previously determined corresponding fluorescence scores of one or more reference fluorescent gemstones.
4. The method of claim 2, wherein the first fluorescence score reflects a color of the fluorescence, and wherein the second fluorescence score reflects an intensity.
5. The method of claim 1, further comprising:
collecting the plurality of images of the sample gemstone using an image capture assembly that maintains a constant image viewing angle at uniquely different image rotation angles.
6. The method of claim 1, further comprising:
collecting the plurality of fluorescence images of the sample gemstone using an image capture assembly that maintains a constant image viewing angle at uniquely different image rotation angles, wherein each fluorescence image in the plurality of fluorescence images corresponds to an image in the plurality of images, and both are captured at the same image rotation angle and image viewing angle.
7. The method of claim 1, further comprising:
determining a fluorescence shielding of each of the plurality of fluorescence images.
8. The method of claim 7, further comprising:
quantifying individual color components in each pixel in the fluorescent mask in each fluorescent image of the plurality of fluorescent images.
9. The method of claim 6, further comprising:
collecting a new plurality of fluorescence images of the sample gemstone using the image capture assembly at the unique different image rotation angles while maintaining the constant image viewing angle, wherein there is a time gap between the time the plurality of fluorescence images are collected and the time the new plurality of fluorescence images are collected;
(vii) assigning a new fluorescence grade by applying steps (i) to (vi) based on the new plurality of fluorescence images; and
comparing the fluorescence level to the new fluorescence level based on the time gap.
10. The method of claim 9, wherein the time gap is between 2 minutes and 5 hours.
Technical Field
The apparatus and methods disclosed herein generally relate to fluorescence grading of gemstones, particularly cut gemstones. In particular, the apparatus and method relate to fluorescence grading of cut gemstones having irregular or fancy shapes. The apparatus and methods disclosed herein further relate to digital image processing based on color component analysis.
Background
Diamonds and other gemstones are often analyzed and graded by a number of trained and skilled practitioners based on the diamond and its visual appearance. For example, the basis of diamond analysis includes analysis of four C's (color, clarity, cut and carat weight), two of which (color and clarity) have traditionally been assessed by manual testing. Gemstones were also evaluated for unusual visual properties. For example, certain gemstones produce fluorescent emissions under UV illumination, and the degree and distribution of this fluorescence is also used to grade such gemstones. As with color and clarity grading, fluorescence grading has previously been evaluated primarily based on human visual perception. Analysis and ranking requires practice of judgment based on visual comparison, formation of opinions, and the ability to draw fine distinctions.
The procedures for detection and analysis are typically time consuming, involving multiple rounds of detection, measurement and review by individual trained and skilled practitioners. The procedures also relate to quality control and may include various non-destructive tests to identify treatments, fillers, or other defects that may affect the quality of the sample. Finally, the program contains a dense visual comparison of the diamond with a reference set of diamonds colorimetric stone used as historical standards with respect to diamond color and fluorescence.
Instruments have been created to improve efficiency and allow gemstone analysis in the absence of trained and skilled practitioners. For example, U.S. patent No. 7,102,742 to Geurtz et al discloses a gemstone fluorescence measurement device that includes an ultraviolet ("UV") emitting chamber, a UV radiation source, and a light meter assembly. The UV radiation source includes an upper light emitting diode ("LED") and a lower LED that radiate the gemstone from both above and below the test gemstone. However, current instruments cannot provide consistent and reproducible levels of fluorescence to fancy shape cut stone; such gemstones are classified as step cuts, heart-shaped, oval, elliptical, pear-shaped, triangular, princess-shaped cuts, or any other cut than the round light-type cut (RBC). In addition, current instruments do not provide hue information and the operator must manually enter the color of the fluorescence. This results in incorrect grading, since the color of the weak fluorescence is not readily visible to the human eye.
There is a need for apparatus and methods that can provide gemstone assessment and grading (e.g., fluorescence grading) that is consistent and accurate with the assessment and grading provided by trained and skilled practitioners.
Disclosure of Invention
In one aspect, provided herein is an apparatus for evaluating fluorescence characteristics of a gemstone. The apparatus includes a light-tight platform, wherein the platform has a surface configured to support a gemstone to be evaluated; a light source shaped to at least partially enclose the platform, wherein the light source is about the same level as or below the platform surface and is designed to provide uniform Ultraviolet (UV) radiation to the gemstone on the platform; an image capture assembly, wherein the image capture assembly is positioned at a predetermined angle relative to a surface of a platform supporting the gemstone, and wherein the image capture assembly and the platform are configured to rotate relative to each other; and a telecentric lens positioned to provide an image of the illuminated gemstone to the image capture assembly.
In one aspect, provided herein is an apparatus for evaluating color characteristics of a gemstone. The apparatus comprises: a light-tight platform, wherein the platform has a surface configured to support a gemstone to be evaluated; a light source over a surface of the platform, wherein the light source is designed to provide uniform Ultraviolet (UV) radiation to the gemstone on the platform; an image capture assembly, wherein the image capture assembly is positioned at a predetermined angle relative to a surface of a platform supporting the gemstone, and wherein the image capture assembly and the platform are configured to rotate relative to each other; and a telecentric lens positioned to provide an image of the illuminated gemstone to the image capture assembly.
In some embodiments, the apparatus further comprises a collimating lens, wherein the collimating lens and the light source are coupled to provide uniform UV illumination to the gemstone on the platform.
In some embodiments, the apparatus further comprises an optical diffuser, wherein the optical diffuser and the light source are coupled to provide uniform UV illumination to the gemstone on the platform.
In some embodiments, the apparatus further comprises a collimating lens and an optical diffuser, wherein the collimating lens, the optical diffuser and the light source are coupled to provide uniform UV illumination to the gemstone on the platform.
In some embodiments, the apparatus further comprises a reflector device having an interior surface that is at least partially spherical and comprises a reflective material. The reflector device at least partially covers the light source and the platform surface and directs UV radiation from the light source towards the gemstone positioned on the platform surface. In some embodiments, the inner surface of the reflector arrangement has a hemispherical shape.
In some embodiments, the apparatus further comprises a computer readable medium for storing the images collected by the image capture component.
In some embodiments, the apparatus further comprises an interface between the light source and the platform surface for adjusting the output intensity of the UV radiation.
In some embodiments, the apparatus further comprises a UV filter between the image capture assembly and the telecentric lens to remove all UV components.
In some embodiments, the UV radiation provided by the light source includes transfer radiation, direct UV radiation, and combinations thereof.
In some embodiments, the light source further provides uniform non-UV illumination to the gemstone.
In some embodiments, the telecentric lens is an object-space telecentric lens or a double telecentric lens.
In some embodiments, the platform is configured to rotate about an axis of rotation that is perpendicular to the side of the platform in which the gemstone is positioned.
In some embodiments, the platform is configured to rotate 360 degrees about the axis of rotation.
In some embodiments, the platform is a flat circular platform, and wherein the axis of rotation passes through the center of the circular platform.
In some embodiments, the platform surface comprises a UV reflective material.
In some embodiments, the platform surface comprises a diffuse UV reflective material.
In some embodiments, the platform surface comprises a white diffuse reflective material.
In some embodiments, the light source is configured as a ring light surrounding the platform surface. In some embodiments, the light source comprises a plurality of light emitting LEDs. In some embodiments, the LED emits 365 nm or 385 nm fluorescence.
In some embodiments, the LED is coupled with a bandpass filter. In some embodiments, the bandpass filter is set at 365 nm or 385 nm.
In some embodiments, the LEDs are configured as ring lights surrounding the platform surface.
In some embodiments, the light source comprises a daylight-approximating light source and a plurality of light emitting LEDs. In some embodiments, the LED is coupled with a bandpass filter. In some embodiments, the bandpass filter is set at 365 nm or 385 nm.
In some embodiments, the predetermined angle between the image capture assembly and the platform surface is between approximately zero degrees and approximately 45 degrees. In some embodiments, the predetermined angle between the image capture assembly and the platform surface is between approximately 10 degrees and approximately 35 degrees.
In some embodiments, the image capture component is selected from a color camera, a CCD camera, and one or more CMOS sensors.
In some embodiments, the image capture assembly captures a plurality of color images of the gemstone illuminated by UV radiation, each image comprising a full image of the gemstone.
In some embodiments, the image capture assembly captures a plurality of color images of the illuminated gemstone, wherein each image is taken when the image capture assembly and the platform surface are at different relative rotational positions, and wherein each image comprises a full image of the gemstone.
In some embodiments, the plurality of color images includes 4 or more than 4 color images, 5 or more than 5 color images, 10 or more than 10 color images, 15 or more than 15 color images, 20 or more than 20 color images, or 800 or more than 800 color images, and wherein each image is taken at a unique image angle and includes a plurality of pixels.
In some embodiments, the fluorescent characteristic is a fluorescent intensity level, a fluorescent color, or a combination thereof.
In one aspect, provided herein is a method of evaluating a fluorescence characteristic of a sample gemstone. For example, the method comprises the steps of: (i) determining a fluorescence mask for a fluorescence image of the plurality of fluorescence images based on the contour mask determined from the image of the plurality of images and based on an apparent fluorescence region of the fluorescence image; (ii) quantifying individual color components in each pixel in a fluorescent mask in a fluorescent image of the plurality of fluorescent images, thereby converting values of the individual color components into one or more parameters representing color characteristics of each pixel; (iii) determining an average value of each of the one or more parameters for all pixels in the defined region in all images of the plurality of fluorescence images; and (iv) calculating a first fluorescence score for the sample gemstone based on an average of the one or more parameters for all pixels in the defined region in all images of the plurality of fluorescence images.
Here, each image of the plurality of images includes a full image of the sample gemstone illuminated by the non-UV light source. Each image of the plurality of fluorescence images comprises a full image of the sample gemstone illuminated by the uniform UV light source. In addition, the image and the fluorescence image are captured under the same conditions except for the illumination light source.
In some embodiments, the method further comprises the step of: (v) a second fluorescence score for the sample gemstone is calculated based on pixels in the contour mask of all of the plurality of fluorescence images.
In some embodiments, the method further comprises the step of: (vi) the fluorescence characteristics of the sample gemstone are assessed by comparing the values of the first fluorescence score or the second fluorescence score with the previously determined corresponding fluorescence scores of one or more reference fluorescent gemstones.
In some embodiments, the first fluorescence score reflects the color of the fluorescence and wherein the second fluorescence score reflects the intensity.
In some embodiments, the method further comprises the step of: multiple images of a sample gemstone are collected using an image capture assembly that maintains a constant image viewing angle at uniquely different image rotation angles.
In some embodiments, the method further comprises the step of: multiple fluorescence images of a sample gemstone are collected using an image capture assembly that maintains a constant image viewing angle at uniquely different image rotation angles. Here, each fluorescence image in the plurality of fluorescence images corresponds to an image in the plurality of images and both are captured at the same image rotation angle and image viewing angle.
In some embodiments, the method further comprises the step of: the fluorescence shielding of each of the plurality of fluorescence images is determined.
In some embodiments, the method further comprises the step of: individual color components in each pixel in the fluorescent mask in each of the plurality of fluorescent images are quantified.
In some embodiments, the method further comprises the step of: collecting a new plurality of fluorescence images of the sample gemstone using an image capture assembly that maintains a constant image view angle at unique different image rotation angles, wherein there is a time gap between when the plurality of fluorescence images were collected and when the new plurality of fluorescence images were collected; (vii) assigning a new fluorescence grade based on the new plurality of fluorescence images by applying steps (i) to (vi); and comparing the fluorescence level to the new fluorescence level based on the time gap.
In some embodiments, the time gap is between 2 minutes and 5 hours.
One skilled in the art will appreciate that any of the embodiments described herein may be used in conjunction with any aspect of an apparatus or method where applicable.
Drawings
Those skilled in the art will appreciate that the drawings described below are for illustrative purposes only. The drawings are not intended to limit the scope of the present teachings in any way.
Fig. 1 depicts an exemplary embodiment of a gemstone optical evaluation system including an optical unit and a gemstone evaluation unit.
Fig. 2A depicts an exemplary schematic embodiment of a gemstone optical evaluation system in a closed configuration (light source not shown).
Fig. 2B depicts an exemplary schematic embodiment of a gemstone optical evaluation system in an open configuration (light source not shown).
Fig. 3 depicts an exemplary embodiment of a sample platform with illumination around a ring light.
Fig. 4 depicts an exemplary diagram showing an image viewing angle and an image rotation angle.
FIG. 5A depicts an exemplary embodiment of a top reflector having an internal reflective surface.
FIG. 5B depicts an exemplary embodiment of a top reflector with an internal reflective surface.
FIG. 5C depicts an exemplary embodiment of a top reflector with an internal reflective surface.
FIG. 5D depicts an exemplary embodiment of a top reflector with an internal reflective surface.
Fig. 6A depicts an exemplary embodiment of a connector module for linking the gemstone assessment unit with the optical unit.
Fig. 6B depicts an exemplary embodiment of a connector module for linking the gemstone assessment unit with the optical unit.
Fig. 6C depicts an exemplary embodiment of a connector module for linking the gemstone assessment unit with the optical unit.
Fig. 7A depicts an exemplary embodiment showing RBC diamonds illuminated by a near daylight light source.
Fig. 7B depicts an exemplary embodiment showing an image of RBC diamonds illuminated by a near daylight source after application of a contour mask.
FIG. 7C depicts an exemplary embodiment, which demonstrates the extraction of the contour mask.
Fig. 7D depicts an exemplary embodiment that demonstrates the extraction of a significant fluorescence area.
FIG. 7E depicts an exemplary embodiment, which demonstrates the extraction of the contour mask.
Fig. 7F depicts an exemplary embodiment that demonstrates the extraction of a significant fluorescence region.
FIG. 8 depicts an exemplary organization of a computer system.
Fig. 9A depicts an exemplary procedure for data collection and analysis.
Fig. 9B depicts an exemplary procedure for data collection and analysis.
Fig. 9C depicts an exemplary procedure for data collection and analysis.
Fig. 10 depicts an exemplary image taken under regular illumination and UV illumination.
Fig. 11 depicts an exemplary embodiment depicting different intensities in the fluorescence emission.
Fig. 12 depicts an exemplary embodiment depicting heterogeneous fluorescence emission.
Fig. 13 depicts an exemplary embodiment depicting fluorescence emission in gemstones having different shapes.
FIG. 14 depicts an exemplary embodiment depicting fluorescence emission in different colors.
FIG. 15 depicts an exemplary embodiment depicting fluorescence emission in different colors.
Detailed Description
Unless otherwise indicated, terms are to be understood in accordance with their ordinary usage by those of ordinary skill in the relevant art. For illustrative purposes, diamonds are used as representative gemstones. Those skilled in the art will appreciate that the apparatus, systems, and methods disclosed herein are applicable to all types of gemstones capable of emitting fluorescent light via UV exposure. Systems AND METHODs FOR color grading based on similar equipment are disclosed in co-pending U.S. patent application entitled "APPARATUS AND METHOD FOR evaluating optical properties OF GEMSTONES," U.S. patent application No. XX/XXX, which is incorporated herein by reference in its entirety.
As mentioned in the background, current automated instruments are not capable of providing an accurate, complete, and consistent assessment of the fluorescence properties of certain gemstones, such as gemstones having irregular or fancy shapes. One reason for explaining this failure is that the fluorescence intensity of the gemstone is significantly affected by factors such as the orientation of the gemstone relative to the detector, the position of the gemstone, and the size of the gemstone. In addition, even if some gemstones are regular round light cuts (RBCs), these gemstones exhibit heterogeneous fluorescence distributions and current instruments still do not provide reproducible fluorescence levels for such stones.
To overcome the existing problems, the improved fluorescence grading instrument as disclosed herein has the following characteristics: (1) providing a consistent and reproducible level of fluorescence to gemstones that are unlimited in size and shape; (2) providing consistent and reproducible fluorescent colors; (3) providing consistent and reproducible levels of fluorescence using easy and quick operation (e.g., an operator need not place stones in the same location).
In one aspect, provided herein is an improved fluorescence grading apparatus for fluorescence assessment of gemstones (such as cut diamonds). The apparatus is suitable for grading gemstones, such as cut diamonds, including gemstones having irregular shapes, sizes, colors and fluorescence distributions. An
Based on functionality, the components of the apparatus disclosed herein may be divided into two main units: a gemstone presentation unit and an optical unit. The gemstone presentation unit provides uniform illumination to the gemstone under analysis and the optical unit captures an image of the presented gemstone.
Additionally and not depicted in fig. 1, the exemplary apparatus further includes a computer processing unit for analyzing the information collected by the image capture component.
As depicted in fig. 1, the exemplary gemstone presentation unit then includes at least two portions: a
In the closed configuration, image information about the gemstone under analysis is received and captured by an optical unit comprising a
In the open configuration (see, e.g., fig. 2B), no image information is collected. Instead, the gemstone undergoing analysis is exposed to an observer. In the open configuration, the revealing gemstone presenting unit has two parts: a
An exemplary
Platform 510 (also referred to as a stage or specimen stage) is important to the system disclosed herein. Importantly, it provides support to the gemstone under analysis. In some embodiments, the top surface of the platform is horizontal and flat. In addition, it serves as a stage for data collection and subsequent analysis of
An exemplary illustration of the relative configuration of the top surface of
In some embodiments, the circular reflective platform is rotatable. For example, the platform is mounted to or connected with the rotor. In a preferred embodiment, the gemstone under analysis is placed at the center of the platform surface, as depicted in fig. 3. The platform is then rotated relative to the optical unit so that images of the gemstone at different angles are collected by the image capture device.
In some embodiments, the platen surface is rotated about an axis of rotation that passes through the center of origin of the circular platen surface and is perpendicular to the platen surface; see, for example, axis Zz depicted in fig. 4.
In some embodiments, the platform is rotated with respect to the optical unit at a set angular variation. The magnitude of these angular variations determines the extent of data collection; for example, how many images will be of a collection of gemstones. For example, if the platform is rotated at an angular variation of 12 degrees, a full rotation will allow 30 images of the gemstone to be collected. The angular variation may be set at any value to facilitate data collection and analysis. For example, the platform is rotated at an angular change of 0.5 degrees or less, 1 degree or less, 1.5 degrees or less, 2 degrees or less, 3 degrees or less, 4 degrees or less, 5 degrees or less, 6 degrees or less, 7 degrees or less, 8 degrees or less, 9 degrees or less, 10 degrees or less, 12 degrees or less, 15 degrees or less, 18 degrees or less, 20 degrees or less, 24 degrees or less, 30 degrees or less, 45 degrees or less, 60 degrees or less, 90 degrees or less, 120 degrees or less, 150 degrees or less, or 180 degrees or less. It will be appreciated that the angular rotational variation may be set any number. It will also be appreciated that the platform may be rotated through any value of total rotational angle, not limited to a full 360 degree rotation. In some embodiments, data (e.g., color imagery) is collected for less than 360 degrees of full rotation. In some embodiments, data (e.g., color imagery) is collected for more than 360 degrees of full rotation.
In some embodiments, the platform or portions thereof (e.g., the top surface) are coated with a reflective surface to achieve reflectivity. In some embodiments, the platform or a portion thereof (e.g., the top surface) comprises a reflective material. In some embodiments, the platform or a portion thereof (e.g., the top surface) is made of a reflective material. In some embodiments, the reflective material is a white reflective material. In some embodiments, the reflective material is Tef1onTMA material. In some embodiments, the reflective material includes, but is not limited to, Polytetrafluoroethylene (PTFE), SpectralonTMBarium sulfate, gold, magnesium oxide, or combinations thereof.
Preferably, the rotatable platform is circular and larger than the size of any sample gemstone to be analyzed. In some embodiments, the platform is horizontal and remains horizontal as it rotates.
In some embodiments, the height of the platform is fixed. In some embodiments, the height of the platform is adjusted manually or via control of a computer program. Preferably, the platform can be raised or lowered by control via a computer program run by a computer unit.
In some embodiments, the platform is flat. In some embodiments, the central region on which the gemstone sample is positioned is flat and the more peripheral region on the platform is not flat. Confirmation that the entire platform adopted a flat dome-like structure.
In some embodiments, the relative position between the platform and the illumination source may be adjusted. For example, the illumination source may be moved closer to or further away from the platform.
The platform may be made of any rigid and non-transparent material, such as metal, wood, black glass, plastic, or other rigid polymeric material. In some embodiments, the platform and/or the area surrounding the platform is coated with a non-reflective or low reflective material.
In its broadest sense, the
In some embodiments, the light generating source is separate from the final illumination assembly, e.g., it is connected together with an external ring light (e.g., by a light transmission cable) to provide the illumination source. In such embodiments, short pass filters and band pass filters are applied for UV light selection before or after the illumination source reaches the annular ring lamp. Thus, the illumination ultimately provided by the annular ring lamp has a defined ultraviolet character; for example, having one or more wavelengths in the UV range. Such a wavelength may be any wavelength from the range of 400 nm to 10 nm, 400 nm to 385 nm, 385 nm to 350 nm, 350 nm to 300 nm, 300 nm to 250 nm, 250 nm to 200 nm, 200 nm to 150 nm, 150 nm to 100 nm, 100 nm to 50 nm, or 50 nm to 10 nm.
In an aspect, a light generating source as disclosed herein is capable of generating fluorescence excitation (e.g., at 365 nanometers). In another aspect, a light-generating source as disclosed herein provides illumination for gemstone profile recognition. This dual functionality is achieved by using a combination of special light sources and different types of light sources.
In some embodiments, a tunable light source capable of emitting both UV and white light is used. For example, the tunable light source includes one or more LEDs. Advantageously, this light source can be used for both contour recognition and fluorescence measurement. For example, a built-in mechanism may be used to allow a user to switch between two operating modes. In some embodiments, the light source (e.g., an emitting UV LED) emits UV illumination at a desired wavelength (e.g., at 365 nanometers). For example, UV LEDs that emit UV light at a single wavelength (e.g., 365 nm or 385 nm) are available (e.g., from Hamamatsu corporation). In some embodiments, a light source (e.g., an emitting UV LED) emits UV illumination at a range and emits a desired wavelength by applying a UV pass filter set at, for example, 365 nanometers.
In such embodiments, the tunable light source provides uniform top illumination or uniform bottom illumination. For top lighting, there are no limitations on the shape and size of the light source. For example, the light source may be circular, partially circular, or completely non-circular (e.g., oval, square, or triangular). There is also no limit to the distance from the gemstone sample. For example, the tunable light source is attached to a reflective interior surface of a top reflective component 60 (e.g., fig. 2B). Combinations of light sources may be used; including but not limited to one or more UV LEDs; one or more UV LEDs with an optical diffuser; one or more UV LEDs with collimating lenses; or one or more UV LEDs with collimating lenses and optical diffusers. One skilled in the art will appreciate that any combination of light sources and optical components that can provide uniform illumination would be suitable for use as the light source in an apparatus as disclosed herein.
For bottom illumination, the light source is preferably a ring light (e.g., fig. 2B) compatible with the shape of the
In some embodiments, more than one light source is used. At least one of these light sources is a UV light source (such as one or more UV emitting LEDs). At least another one of the light sources is a white light source. Any suitable white light source may be used, including, but not limited to, fluorescent lamps, halogen lamps, Xe lamps, tungsten lamps, metal halide lamps, laser induced white light (LDLS), or combinations thereof.
Many combinations may be used in such embodiments. For example, two ring lamps may be used: one to provide uniform UV illumination and one to provide uniform near daylight illumination. In this combination, in some embodiments, both light sources provide bottom illumination. In some embodiments, one ring light provides bottom illumination while the other provides top illumination.
In another exemplary combination, the light source includes a ring LED light source and a white light source. In some embodiments, a ring UV LED is used to provide bottom illumination and a white light source provides top illumination.
In another exemplary combination, the light source includes an annular white light source and an LED light source. In some embodiments, an annular white light source is used to provide bottom illumination and a UV LED source provides top illumination.
As mentioned, a white light source includes a near daylight light source. Exemplary near-daylight light sources include, but are not limited to, one or more halogen lamps with color balancing filters, a plurality of light emitting diodes arranged in a ring-like structure around the platform surface, fluorescent lamps, Xe lamps, tungsten lamps, metal halide lamps, laser induced white light (LDLS), or combinations thereof. In some embodiments, a color balancing filter is used to create a daylight-equivalent light source.
In some embodiments, where applicable, either the white light source or the UV light source may be ring light. For example, for a UV light source, the components that can produce UV illumination are arranged in a circular or near-circular shape. For example, UV light emitting diodes emitting UV light at a single wavelength (e.g., 365 nm or 385 nm) are available (e.g., from Hamamatsu corporation). In some embodiments, a ring light has been embedded within one or more UV LEDs.
In some embodiments, a cable (such as a gooseneck light guide, a flexible light guide, each containing one or more branches) is used to connect the ring light to the light-generating source.
The UV illumination source may take any shape and size suitable for optical analysis of the sample gemstone. For example, the illumination source may be a point light, a circular light, an annular light, an elliptical light, a triangular light, a square light, or any other light of a suitable size and shape. In some embodiments, the light illumination source is annular or circular in shape, having a diameter greater than the diameter of the circular platform.
The UV illumination assembly provides input light under which the sample gemstone can be analyzed. Advantageously, gemstones that fluoresce under UV illumination may be analyzed with high sensitivity in environments where there is no or little light interference (e.g., from ambient or other light). Here, visible fluorescence is emitted as a result of exposure to UV illumination. When the effect from UV illumination is excluded (e.g., setting the light filter on the detector or image capture component to only the visible range), the emitted fluorescence is compared to zero background (e.g., no fluorescence). Here, the signal-to-noise ratio is very high due to the low or near zero noise level.
Modular approaches to the design of equipment have been employed to provide experimental flexibility. In some embodiments, the intensity of the UV illumination may be adjusted to optimize image collection.
Modular approaches to the design of equipment have been employed to provide experimental flexibility. In some embodiments, the intensity of the UV illumination may be adjusted to optimize image collection.
As shown in fig. 2A and 2B, the top reflector module may be moved over the area in which the sample gemstone is positioned. In the closed configuration shown in fig. 2A, the interior chamber of the top reflector module serves as a sealed and isolated sample chamber in which the sample gemstone is analyzed in a controlled environment. For example, ambient or other light is excluded from the chamber. The user can adjust the light intensity within the chamber to optimize data collection. In some embodiments, the collected data comprises color images of the gemstone viewed from different angles.
Fig. 5A-5D illustrate an exemplary embodiment of a
Inside the
x＝R(cosθ+θsinθ)
y-R (sin θ - θ cos θ), where R is the radius of the circle and θ is the angular parameter of the radian. The involute surface directs reflected light toward the central circular area so that the illumination of the gemstone under analysis is optimized.
In some embodiments, the
In some embodiments with bottom UV illumination (e.g., when using a ring lamp of UV LEDs), one or more reflective materials are used to reflect the UV illumination toward the gemstone. In some embodiments with top UV illumination, no reflective material is required.
As illustrated in fig. 2B, an
Fig. 6A-6C provide a more detailed illustration of an exemplary implementation of an optical connector module. In this case, the connector is a lens cover for receiving
In addition, the connector also has an
A lens cover or other optical connector module allows the integration of two different functional components. It is designed so that no or very little ambient or other light enters the sample chamber. In some embodiments, additional components (such as sealing tape) may be used to exclude ambient or other light.
Another major functional component of the system is the optical unit through which the data of the gemstone under analysis passes. The optical unit provides a sample chamber that enables collection of the visible spectrum from the region containing the sample gemstone, while excluding light from outside the chamber. Optical measurements (such as images) are captured of the area containing the sample gemstone and analysis of the detailed structure of the image can be passed to provide some insight into the cause of certain stones that previously had anomalous grading results.
The exemplary embodiments disclosed herein include, but are not limited to, two important functional modules in an optical unit, a
The telecentric lens is used to provide an image of the illuminated gemstone to the image capture assembly. Telecentricity refers to a unique optical property in which the primary rays passing through a certain lens design (oblique rays passing through the center of the aperture top) are collimated and parallel to the optical axis in image and/or object space. A telecentric lens is a compound lens that has its entrance or exit pupil at infinity. Advantageously, a telecentric lens provides constant magnification over a range of working distances (no change in object size), virtually eliminating solid angle errors. For many applications, this means that object movement does not affect image magnification, allowing for highly accurate measurements in measurement applications. This level of accuracy and repeatability is not achieved with standard lenses. The simplest way to make the lens telecentric is to stop the aperture at one of the focal points of the lens.
There are three types of telecentric lenses. An entrance pupil at infinity makes the lens object-space telecentric. An exit pupil at infinity makes the lens image-space telecentric. If both pupils are infinity, the lens is double telecentric.
Telecentric lenses with high depth of field are used in the systems disclosed herein. In some embodiments, the telecentric lens used is an object-space telecentric lens. In some embodiments, the telecentric lens is a double telecentric lens. In a preferred embodiment, the zoom should be fixed for full image collection of a given gemstone stone to further ensure consistency.
Advantageously, the present apparatus and system do not require the sample gemstone to be placed at the center of the platform surface. In addition, the telecentric lens does not distinguish between the sizes of these sample gemstones. The same telecentric lens can be used to collect images of very small gemstones and significantly larger gemstones.
The optical unit further includes an image capture component or detector, such as a digital camera. To capture only the fluorescence emitted from these gemstones, filters are applied to exclude interference from UV illumination.
In some embodiments, the
For more accurate analysis results, the resolution limit of the collected digital images is 600 pixels × 400 pixels or more. In some embodiments, each pixel has an 8-bit value (e.g., 0 to 255) for each color component. The analog-to-digital converter (ADC) of a digital camera is 8 bits or more to efficiently process the information embedded in the pixels with little or no loss in image quality. In some embodiments, the ADC is 10 bits or more, depending on the dynamic range of the image capture component. In some embodiments, the ADC is between 10 and 14 bits.
In some embodiments, the color components in a pixel include, but are not limited to, red (R), green (G), and blue (B). In some embodiments, the color components in a pixel include, but are not limited to, cyan (C), magenta (M), yellow (Y), and a key (black or B). In some embodiments, the color components in a pixel include, but are not limited to, red (R), yellow (Y), and blue (B).
Image viewing angle:as depicted in fig. 4, the image capture device of the optical unit (or
Image rotation angle:as also depicted in fig. 4, the relative rotational position between the imaging capture assembly and a predefined location on the platform (e.g., point 540) may be described by the image rotation angle β. For example, the image capture assembly and the platform surface may be rotated relative to each other such that the image rotation angle is changed at a set angular change between successive images. For example, the angular variation between two successive images may be 0.5 degrees or less, 1 degree or less, 1.5 degrees or less, 2 degrees or less, 3 degrees or less, 4 degrees or less, 5 degrees or less, 6 degrees or less, 7 degrees or less, 8 degrees or less, 9 degrees or less, 10 degrees or less, 12 degrees or less, 15 degrees or less, 18 degrees or less, 20 degrees or less, 24 degrees or less, 30 degrees or less, 45 degrees or less, 60 degrees or less, 90 degrees or less, or 180 degrees or less. It will be appreciated that the angular rotational variation may be set any number.
It will also be appreciated that the platform and image capture assembly may be rotated relative to each other by any value of total rotational angle, not limited to a full 360 degree rotation. In some embodiments, the data (e.g., color images) is collected for less than a full 360 degree rotation. In some embodiments, the data (e.g., color images) is collected for more than a 360 degree full rotation.
The angular rotation variation may be varied while collecting a set of images of the same sample gemstone. For example, the angular difference between
The number of images collected for a given sample gemstone varies depending on the characteristics of the gemstone. Exemplary characteristics include, but are not limited to, shape, cut, size, color, and the like.
The visible spectrum from the region on the surface of the platform containing the sample gemstone is selectively collected. In some embodiments, a plurality of color images are collected for each gemstone. In some embodiments, a plurality of colorless images are collected for each gemstone. The color image is useful for determining, for example, the color grade of a cut diamond.
In some embodiments, images captured by a CCD camera will be processed to identify regions of different color or fluorescence intensity, as will be discussed further in the following sections. Further, colorimetric calculations may be performed on these different regions using the red, green, and blue signals from the camera pixels. In some embodiments, such a calculation will be sufficiently accurate to give a fluorescence rating. In some embodiments, such calculations will be sufficiently accurate to provide a distribution of colours across the diamond, and comparison of these colour calculations with those obtained from the measured spectra may help identify diamonds that may give anomalous results.
In some embodiments, the fluorescence level is determined based on color values calculated from the entire sample gemstone. In some embodiments, the fluorescence level is determined based on color values calculated from the color region of the sample gemstone.
The resolution and capacity of the detector can be determined by the number and size of pixels in the detector array. In general, the spatial resolution of digital images is limited by the pixel size. Unfortunately, while reducing the pixel size improves spatial resolution, this is at the cost of signal-to-noise ratio (SNR or signal-to-noise ratio). Specifically, the signal-to-noise ratio is improved when increasing the image sensor pixel size or cooling the image sensor. Meanwhile, if the image sensor resolution remains the same, the size of the image sensor is increased. Higher quality detectors, such as better digital cameras, have large image sensors and relatively large pixel sizes for good image quality.
In some embodiments, the detector of the present invention has a size of 1 square micron or less; 2 square microns or less; 3 square microns or less; 4 square microns or less; 5 square microns or less; 6 square microns or less; 7 square microns or less; 8 square microns or less; 9 square microns or less; 10 square microns or less; 20 square microns or less; 30 square microns or less; 40 square microns or less; 50 square microns or less; 60 square microns or less; 70 square microns or less; 80 square microns or less; 90 square microns or less; 100 square microns or less; 200 square microns or less; 300 square microns or less; 400 square microns or less; 500 square microns or less; 600 square microns or less; 700 square microns or less; 800 square microns or less; 900 square microns or less; 1000 square microns or less; 1100 square microns or less; 1200 square microns or less; 1300 square microns or less; 1400 square microns or less; 1500 square microns or less; 1600 square microns or less; 1700 square microns or less; 1800 square microns or less; 1900 square micrometers or less; 2000 square microns or less; 2100 square microns or less; 2200 square microns or less; 2300 square microns or less; 2400 square micrometers or less; 2500 square microns or less; 2600 square microns or less; 2700 square micrometers or less; 2800 square microns or less; 2900 square microns or less; 3000 square microns or less; 3100 square microns or less; 3200 square microns or less; 3300 square microns or less; 3400 square microns or less; 3500 square microns or less; 3600 square microns or less; 3700 square microns or less; 3800 square micron or less; 3900 square micrometers or less; 4000 square microns or less; 4100 square microns or less; 4200 square microns or less; 4300 square micrometers or less; 4400 square microns or less; 4500 square microns or less; 4600 square microns or less; 4700 square microns or less; 4800 square microns or less; 4900 square microns or less; 5000 square microns or less; 5100 square microns or less; 5200 square micrometers or less; 5300 square microns or less; 5400 square micrometers or less; 5500 square microns or less; 5600 square micrometers or less; 5700 square microns or less; 5800 square microns or less; 5900 square microns or less; 6000 square microns or less; 6500 square micron or less; 7000 square microns or less; 7500 square microns or less; 8000 square microns or less; 8500 square microns or less; 9000 square microns or less; or pixel sizes of 10000 square microns or less. In some embodiments, the pixel size is greater than 10000 square microns, for example up to 20000 square microns, 50000 square microns or 100000 square microns.
In some embodiments, the exposure time to the detector may be adjusted to optimize the image quality and to facilitate determination of the level of an optical property of the gemstone, such as color or fluorescence level. In some embodiments, the fluorescence emission is rather weak and thus requires long exposure times for assessing fluorescence quality. For example, the exposure time to the CCD detector may be 0.1 milliseconds (ms) or longer, 0.2 ms or longer, 0.5 ms or longer, 0.8 ms or longer, 1.0 ms or longer, 1.5 ms or longer, 2.0 ms or longer, 2.5 ms or longer, 3.0 ms or longer, 3.5 ms or longer, 4.0 ms or longer, 4.5 ms or longer, 5.0 ms or longer, 5.5 ms or longer, 6.0 ms or longer, 6.5 ms or longer, 7.0 ms or longer, 7.5 ms or longer, 8.0 ms or longer, 8.5 ms or longer, 9.0 ms or longer, 9.5 ms or longer, 10.0 ms or longer, 15.0 ms or longer, 20.0 ms or longer, 25.0 ms or longer, 30.0 ms or longer, 35.0 ms or longer, 40.0 ms or longer, 45.0 ms or longer, 0.65 ms or longer, 0.0 ms or longer, 0.55 ms or longer, 0.0 ms or longer, 0 ms or longer, 0.5 ms or longer, 4 or longer, 4.0 ms or longer, 4.5 ms or longer, 4 ms or longer, 75.0 milliseconds or longer, 80.0 milliseconds or longer, 85.0 milliseconds or longer, 90.0 milliseconds or longer, 95.0 milliseconds or longer, 100.0 milliseconds or longer, 105.0 milliseconds or longer, 110.0 milliseconds or longer, 115.0 milliseconds or longer, 120.0 milliseconds or longer, 125.0 milliseconds or longer, 130.0 milliseconds or longer, 135.0 milliseconds or longer, 140.0 milliseconds or longer, 145.0 milliseconds or longer, 150.0 milliseconds or longer, 175.0 milliseconds or longer, 200.0 milliseconds or longer, 225.0 milliseconds or longer, 250.0 milliseconds or longer, 275.0 milliseconds or longer, 300.0 milliseconds or longer, 325.0 milliseconds or longer, 350.0 milliseconds or longer, 375.0 milliseconds or longer, 400.0 milliseconds or longer, 425.0 milliseconds or longer, 450.0 milliseconds or longer, 475.0 milliseconds or longer, 500.0 or longer, 550.0 or longer, 600.0 milliseconds or longer, 600.0.0, 800.0 milliseconds or longer, 700 milliseconds or longer, 800.0 milliseconds or longer, 800 milliseconds or longer, 700 milliseconds or longer, 800.0 milliseconds or longer, or equal to form a part of a semiconductor memory cell structure, 900.0 milliseconds or more, 950.0 milliseconds or more, 1 second or more, 1.1 seconds or more, 1.2 seconds or more, 1.3 seconds or more, 1.4 seconds or more, 1.5 seconds or more, 1.6 seconds or more, 1.7 seconds or more, 1.8 seconds or more, 1.9 seconds or more, 2 seconds or more, 2.5 seconds or more, 3 seconds or more. It is understood that the exposure time may vary with respect to, for example, the light source intensity.
In another aspect, the methods and systems disclosed herein are used to detect or assess changes in the fluorescence properties of a sample gemstone over time. For example, the color of the fluorescence of the gemstone may change over time. Likewise, the intensity of the fluorescence of the gemstone may change over time.
In such embodiments, the plurality of sets or images (e.g., color images) are collections of the gemstone over a period of time. For example, using the system disclosed herein, sets of images are automatically collected over multiple image angles. There is no limit on how many sets of images can be collected over time, e.g., two or more sets of images can be collected; three or more groups of images; four or more groups of images; five or more groups of images; six or more groups of images; seven or more groups of images; eight or more groups of images; nine or more sets of images; 10 or more than 10 images; 15 or more than 15 images; 20 or more than 20 images; 30 or more than 30 images; 50 or more than 50 images; or 100 or more than 100 images.
In some embodiments, all sets of images are collected by applying the same gemstone in the same system configuration; for example, the same camera, the same imaging angle, the same reflector, the same platform, etc. are used.
In the multiple sets of images, two successive sets of images are used for time intervals ranging from minutes to hours or even days, respectively, depending on the nature of the color change of the stone. The duration of the time gap is determined by how quickly the color change can occur in the sample stone. There is no limit to how long or short the time gap may be. For example, the time gap may be two minutes or less; five minutes or less; 10 minutes or less; 20 minutes or less; 30 minutes or less; 60 minutes or less; 2 hours or less; 5 hours or less; 12 hours or less; 24 hours or less; 2 days or less; 5 days or less; or 10 days or less.
In some embodiments, the calculations are done for each set of images to assign a fluorescence rating to the sample gemstone. The fluorescence levels from the multiple sets of images are then compared to determine the change in fluorescence over time.
In another aspect, a data analysis unit is also provided herein, including both hardware components (e.g., a computer) and software components.
The data analysis unit stores, converts, analyzes, and processes the images collected by the optical unit. The computer unit controls various components of the system, such as rotation and height adjustment of the platform, adjustment of the intensity and exposure time of the illumination source. The computer unit also controls zooming and adjusting the relative position of the optical unit and the gemstone platform.
Fig. 8 depicts an
The
The
In some embodiments, the operation of
In some embodiments according to the invention, the
Data processing application 838:in some embodiments according to the invention, the
The content management tool 840:in some embodiments,
The databases stored on
In some implementations, the
System management and monitoring tools 842:in some embodiments according to the invention, system management and
Network application 846:in some embodiments, the
The calculation and analysis tool 848:the calculation and
System adjustment tool 850:the
In addition to the modules identified above, the
The
Reference gemstone database 860:data (e.g. grade value or L) of an existing or known reference or colorimetric (master) stone*、C*The a or b value) is stored in the
Optional user password database 862:in some embodiments, an
In one aspect, provided herein are methods for system calibration, data collection, data processing, and analysis. For example, a color digital image of a gemstone is obtained, processed, and calculated to provide one or more values for assessing and grading the quality of the cut gemstone (such as a diamond).
Not all gemstones fluoresce upon UV exposure. Even for gemstones that do emit fluorescence upon UV exposure, the level of fluorescence is highly unlikely to be uniform, as the fluorescent material within the stone is typically not uniformly distributed. Further, not all parts of the stone may emit fluorescence. An important aspect of fluorescence grading is to accurately identify the regions within which fluorescence is emitted and to focus data analysis within such regions to improve accuracy.
For fluorescence analysis, at least two sets of test data were used. For example, for a given sample gemstone under the same conditions (e.g., at a set image viewing angle and a set image rotation angle), at least two images are captured: one image under regular non-UV illumination (e.g., under a visible near daylight light source), and another image under UV illumination (e.g., a fluorescent or fluorescent image, also referred to as a UV image). In some embodiments, the set of images captured under regular non-UV illumination is used to extrapolate the contour mask. In some embodiments, the set of images captured under UV illumination is used to extrapolate the area of fluorescence (e.g., fig. 7C and 7D). In contrast, a set of test data is used for color analysis. For example, a sample gemstone is a multiple color image capture of a sample gemstone under the same illumination conditions (e.g., under an approximately daylight light source) while varying the image rotation angle at set intervals at the same image viewing angle using a telecentric lens.
FIGS. 7A and 7B show images of a diamond in which the background white color has been masked to highlight the presence of the diamond. As depicted in fig. 7B, a contour mask is formed around the dark area of the diamond. In some embodiments, the contour mask corresponds to a solid border or edge of the sample gemstone, as viewed at a given image viewing angle and a given image rotation angle. Thus, the opening of the contour mask encompasses the full image or the entire area of the sample gemstone at a given image viewing angle and image rotation angle. As illustrated in the methods of the analysis section, such contour masks may be defined for each image to isolate the area of analysis and extract measurements (such as width and height).
Fig. 7C depicts an illuminated gemstone under a visible light source before (a) and after (b) contour extraction. As illustrated, the resulting contour mask corresponds to the physical size of the diamond in two dimensions under the particular image capture conditions. Fig. 7D depicts the gemstone under illumination by a UV light source in a fluorescence image, before (a) and after (b) fluorescence extraction. Here, it is important to understand that the region that appears to be fluorescent in the fluorescence image (i.e., the apparent fluorescence region) may be different in size (e.g., larger) than the region within the gemstone capable of emitting fluorescence, as the region that can self-emit fluorescence extends when the fluorescence emission is captured in the image. As shown in (b), in fact, the apparent fluorescence area is larger than the physical size of the diamond itself due to fluorescence reflection from the sample platform. Thus, the apparent fluorescence area is much larger than the opening of the contour mask, as illustrated in the comparison between fig. 7c (b) and fig. 7d (b). In some embodiments, the contour mask is used to calculate the fluorescence intensity; for example as represented by the parameter L according to the international commission on illumination (CIE or international commission on illumination). Here, the entire region of the gemstone will be evaluated to accurately quantify the total fluorescence emission level of the gemstone.
The fluorescent screen serves to define an area within the gemstone that will be subject to further analysis or calculation. In the case depicted in fig. 7C and 7D, the apparent fluorescence area is substantially larger than the physical dimensions of the gemstone (e.g., as represented by the opening masked by the outline), which implies that the apparent fluorescence area includes an area that does not correspond to any portion of the gemstone. To eliminate inaccuracies, any fluorescence beyond the physical boundaries of the gemstone is removed from further data analysis. Only the fluorescence measurements from within the boundaries of the gemstone will be further calculated and analyzed to provide an estimate of the fluorescence emitted from the gemstone. When fluorescence light is emitted from the entire gemstone and the apparent fluorescence area covers the entire gemstone, the fluorescence shield is identified by overlaying the apparent fluorescence area (e.g., fig. 7d (b)) onto the outline shield of the gemstone (e.g., fig. 7c (b)). Any area outside the boundary defined by the contour mask in the apparent fluorescence area will be eliminated. The remaining portion of the distinct fluorescent zone corresponds to the phosphor screen. In fact, the screening is calculated by FIG. 7C (b). times.7D (b). Can you change the above description accordingly? Under the above description, a heterogeneous strong fluorescent diamond may not be covered.
In other gemstones, the apparent fluorescence area may also be smaller than the solid boundaries of the stone, as defined by the outline mask and as shown in fig. 7E and 7F. Fig. 7E shows contour extraction from (a) to (b), which is similar to that of fig. 7C. In fig. 7F, fluorescence is emitted from only a limited region within the gemstone. The areas are small and disjointed. After applying fluorescence extraction, a distinct fluorescence area was obtained as indicated in fig. 7f (b). In this case, the apparent fluorescence area also contains patches of disjointed smaller areas. The total apparent fluorescence area is substantially smaller than the contour mask shown in fig. 7E.
In the case depicted in fig. 7E and 7F, the apparent fluorescence area is substantially smaller than the physical size of the gemstone (e.g., as represented by the opening masked by the outline). In addition, fluorescence in the distinct fluorescent regions is non-continuous, meaning that non-emitting regions have been excluded from the distinct fluorescent regions. To eliminate inaccuracies, in some embodiments, a phosphor mask with an opening matching the smaller apparent phosphor zone will be used to define a region within the gemstone for further analysis. Again, the fluorescence mask is identified by overlaying the apparent fluorescence area (e.g., fig. 7f (b)) onto the outline mask of the gemstone (e.g., fig. 7e (b)). Any area outside the boundary defined by the contour mask in the apparent fluorescence area will be eliminated. The remaining portion of the distinct fluorescent zone corresponds to the phosphor screen. The fluorescence measurements within the openings of the fluorescence-only shield will be further calculated and analyzed to provide an estimate of the fluorescence emitted from the gemstone.
In some embodiments, the phosphor screen comprises a continuous opening; for example, see (b) of fig. 7C. In some embodiments, the phosphor screen comprises discontinuous openings; for example, see (b) of fig. 7F. In some embodiments, the total open area of the fluorescent shield corresponds to the physical size of the gemstone. In some embodiments, the total open area of the fluorescent shield is substantially smaller than the physical size of the gemstone.
An exemplary process based on the apparatus and system disclosed herein is summarized in fig. 9A. Those skilled in the art will appreciate that the steps provided are exemplary and may be applied in any order or in any possible combination.
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Fluorescence measures the visible light emitted by a fluorescent material (e.g., a phosphor) when it receives input energy from UV illumination. In general, it will be appreciated that the more intense the UV illumination, the more intense the fluorescent material will emit visible light.
In some embodiments, the intensity of the input UV illumination is adjusted to optimize the fluorescence measurement. For example, a wattmeter (e.g., a PM160T thermal sensor wattmeter from Thorlabs) is used to measure the light intensity from the UV light source. The UV intensity is adjusted to the same intensity level to provide reproducible fluorescence measurements.
At
In a preferred embodiment, the angular difference between successive color images remains constant throughout the collection of all images. Any of the configurations disclosed herein (e.g., relating to image viewing angle and image rotation angle) may be applied to the image collection procedure. For example, if it is set that the camera takes 30 pictures per second and one full rotation of the sample platform takes 3 seconds, then 90 images will be collected after one full rotation. In some embodiments, the platform surface completes at least one full rotation relative to the image capture assembly. In some embodiments, the rotation is less than a full rotation. In some embodiments, the rotation is more than full rotation; for example, 1.2 full rotations or less, 1.5 full rotations or less, 1.8 full rotations or less, 2 full rotations or less, 5 full rotations or less, or 10 full rotations or less.
At
There are many methods for edge detection, and most of them can be grouped into two categories: based on seek and based on zero crossings. Search-based methods detect edges by first computing a measure of edge strength (typically a first derivative, such as gradient magnitude), and then searching for local directional maxima of the gradient magnitude using a computed estimate of the local orientation of the edge (typically the gradient direction). The zero crossing-based method searches for zero crossings in a second derivative computed from the image to find edges, typically Laplacian zero crossings or nonlinear differential zero crossings.
The main differences between the hitherto known edge detection methods are the type of smoothing filter applied and the method of calculating the measure of the edge strength. Because many edge detection methods rely on the computation of image gradients, they differ in the type of filter used to compute the gradient estimates in the x-direction and y-direction.
Here, any applicable method for extracting the contour mask may be used, including, for example, commercially available software products (such as Photoshop)TMEtc.) of the edge decision filter. Additionally, for example, a sample algorithm may be developed in which any contiguous region in an image having color values that match the background white color (as previously calibrated) is defined as black. Thus, the continuous black area will form a contour mask with an opening corresponding to the full image of the sample gemstone.
Based on the contour mask, the values of the geometric parameters (e.g., width and height of the gemstone as depicted in fig. 7B) are determined for each open area corresponding to a full image of the sample gemstone. The contour mask is used for more accurate or automatic measurement of the geometric parameters. In essence, the geometric parameters are determined based on the opening of each contour mask or more precisely each contour mask. Measurements are taken for each image. After this step, sets of measurements are determined for the color images (or their corresponding contour masks), including, for example, width measurements and height measurements.
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For example, in fig. 7d (a), the fluorescence now passes through the entire gemstone, resulting in a large and continuous region of apparent fluorescence depicted in fig. 7d (b). In this case, the fluorescence shield is a composite of the outline shield and the apparent fluorescence area, which is obtained by removing all the area beyond the physical boundary of the sample gemstone (i.e., the outline shield). The fluorescence shield is identified by overlaying the apparent fluorescence area on the outline shield and then removing any fluorescence that exceeds the physical boundaries of the outline shield. The fluorescent shield is an intersecting component of the distinct fluorescent area and the contour shield. In a particular example, because the apparent fluorescence area is continuous and the contour mask is always continuous, the resulting fluorescence mask is essentially a contour mask, as outlined in
It will be appreciated that if the extracted apparent fluorescence regions are non-contiguous but also extend beyond the physical boundaries of the sample gemstone (i.e. the outline mask), then the resulting fluorescence mask will be an apparent fluorescence region with the regions outside the boundaries of the outline mask excluded (
In some embodiments, the luminescent screen corresponds to 20% or less of the entire gemstone, 25% or less of the entire gemstone, 30% or less of the entire gemstone, 35% or less of the entire gemstone, 40% or less of the entire gemstone, 45% or less of the entire gemstone, 50% or less of the entire gemstone, 55% or less of the entire gemstone, 60% or less of the entire gemstone, 65% or less of the entire gemstone, 70% or less of the entire gemstone, 75% or less of the entire gemstone, 80% or less of the entire gemstone, 85% or less of the entire gemstone, 90% or less of the entire gemstone, or 100% or less of the entire gemstone. In some embodiments, the phosphor mask corresponds to the entire solid area of the sample gemstone.
To improve accuracy and consistency, only the pixels within the fluorescent mask will undergo calculations and further analysis (e.g., step 900). Exemplary data collection, calculation and analysis procedures are depicted in fig. 9B and 9C.
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in some embodiments, the standards published by the CIE are used (e.g., doA color matching function as a function of wavelength and a table of illuminants). The curve of a standard daylight illuminant has a correlated color temperature, D, of 6500K65. Here, the illuminant is represented by a function HD65And (lambda) is shown. These color matching functions:
In some embodiments, the first fluorescence score represents a color or hue characteristic of the fluorescence emitted by the sample gemstone.
Fig. 9C continues to depict an exemplary procedure for fluorescence level analysis. At
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Computing color characteristics (e.g., L)*、C*And b*) Examples of (a) are as follows. Since diamond is a transparent material, the sum of the transmission spectrum T (λ) and the reflection spectrum R (λ) is used in the calculation of the tristimulus values X, Y and Z:
the chromaticity coordinates x and y are then defined as:
an attempt to achieve a "perceptually uniform" color space is the CIE1976 color space, otherwise known as the CIELAB color space. Its parameters were calculated from the tristimulus values as follows:
the brightness of the light emitted by the light source,
the red and green parameters are set according to the parameters,
and a yellow-blue parameter,
wherein XW、YWAnd ZWIs the tristimulus value for the white point corresponding to the selected illuminant (in this case D65).
The saturation or chroma is expressed as:
The source may be used for image/color conversion and warping. For example, an open CV item hosted at docs < dot > opencv < dot > org may be used to convert RGB values to CIE L, a, b values. In addition, the same or similar resources allow for conversion between RGB values and hue-saturation-value (HSV) values, RGB values and hue-saturation-luminance (HSL) values, RGB values and CIE Luv values in Adams color difference color space.
The present invention may be implemented as a computer system and/or a computer program product comprising a computer program mechanism embedded in a computer-readable storage medium. Further, any of the methods of the present invention can be implemented in one or more computers or computer systems. Further, any of the methods of the present invention can be implemented in one or more computer program products. Some embodiments of the invention provide a computer system or computer program product encoding or having instructions for performing any or all of the methods disclosed herein. Such methods/instructions may be stored on a CD-ROM, DVD, magnetic disk storage product, or any other computer readable data or program storage product. Such methods may also be embedded in permanent storage, such as a ROM, one or more programmable chips, or one or more Application Specific Integrated Circuits (ASICs). Such permanent storage may be localized in a server, an 802.11 access point, an 802.11 wireless bridge/station, a repeater, a router, a mobile phone, or other electronic device. Such methods encoded in a computer program product may also be distributed electronically, via the internet or otherwise, via transmission of a computer data signal (in which the software modules are embedded) either digitally or on a carrier wave.
Some embodiments of the invention provide a computer system or computer program product containing any or all of the program modules as disclosed herein. These program modules may be stored on a CD-ROM, DVD, magnetic disk storage products, or any other computer readable data or program storage product. Program modules may also be embedded in permanent storage, such as ROM, one or more programmable chips, or one or more Application Specific Integrated Circuits (ASICs). Such permanent storage may be localized in a server, an 802.11 access point, an 802.11 wireless bridge/station, a repeater, a router, a mobile phone, or other electronic device. The software modules in the computer program product may also be distributed electronically, via the internet or otherwise by transmission of a computer data signal in which the software modules are embedded, either digitally or over a carrier wave.
Having described the invention in detail, it will be apparent that modifications, variations, and equivalent embodiments are possible without departing from the scope of the invention defined in the appended claims. Further, it should be understood that all examples in this disclosure are provided as non-limiting examples.