System and method for tracing a gemstone's journey from the mine to the consumer by detecting inclusions in the gemstone

Abstract

There are provided method for detecting inclusions in a gemstone comprising illuminating the gemstone by successively producing illumination patterns on the gemstone each selected so as to simultaneously provide an internal uniform illumination of one or more predetermined light exit regions of the gemstone, and each being defined by a unique combination of spaced apart light entrance areas illuminated simultaneously from corresponding illumination directions. The method further comprises capturing a plurality of images of the gemstone when illuminated as indicated above, processing the images and identifying inclusions in the images based on non-uniformities in the internal illumination detected in the images. The illumination patterns can be produced by an illumination system configured to selectively illuminate the spaced apart light entrance areas of the gemstone from corresponding illumination directions. The illumination system can be controlled by a controller configured to cause the system to successively produce the illumination patterns. The images of the gemstone can be captured by an image acquisition device and processed by an image processing system configured for identifying inclusions based on non-uniformities in the internal illumination detected in the images.

1 - 25 . (canceled) 
     
     
         26 . A system for use in detecting inclusions in a gemstone, comprising:
 (a) an illumination system configured to selectively illuminate each of a plurality of spaced apart light entrance areas of the gemstone from corresponding illumination directions, and to provide a number of illumination patterns each defined by a unique combination of said light entrance areas;   (b) a controller configured to control said illumination system to successively produce illumination patterns each selected so as to provide an internal uniform illumination of one or more predetermined light exit regions of the gemstone; and   (c) an image acquisition device configured to capture images of the gemstone at different depths along height of the gemstone when illuminated by the illumination system as defined in item (b); said images being indicative of the inclusions in the gemstone.   
     
     
         27 . The system of  claim 26 , further comprising an image processing system configured for processing said images to identify said inclusions based on non-uniformities in the internal illumination detected in said images. 
     
     
         28 . The system of  claim 26 , wherein the illumination system comprises a first hemispherical illumination surface in the form of a first diffusively reflecting surface and a first light source configured to selectively illuminate a plurality of first zones on the first hemispherical illumination surface, the first reflecting surface and the first light source being disposed on two sides of the gemstone. 
     
     
         29 . The system of  claim 28 , further comprising a transparent table configured for mounting the gemstone thereon and wherein the illumination system comprises a second hemispherical illumination surface in the form of a second diffusively reflecting surface, and a second light source configured to selectively illuminate a plurality of second zones on the second hemispherical illumination surface, the second reflecting surface and the second light source are disposed on the same side of the gemstone. 
     
     
         30 . The system of  claim 28 , wherein the system has an optical axis passing through a center of the first hemispherical illumination surface, and the latter surface comprises an opening surrounding said axis, and wherein the illumination system comprises a third light source configured to illuminate the gemstone through said opening and/or the image acquisition device is configured to capture images of the gemstone through said opening. 
     
     
         31 . The system of  claim 26 , wherein the at least one predetermined region comprises at least one facet of the gemstone. 
     
     
         32 . The system of  claim 26 , wherein the controller is configured to calculate the illumination pattern using a ray tracing model. 
     
     
         33 . The system of  claim 27 , wherein said image processing system is configured to perform said detecting using at least one of the following:
 i) comparing images of said predetermined light exit regions with their simulated images calculated as if these regions were illuminated uniformly; or ii) detecting differentiation of illumination intensity of said regions relative to a predetermined intensity at said regions.   iii) detecting differentiation of illumination intensities of pixels, relating to intensities of said regions, relative to their surrounding pixels.   
     
     
         34 . The system of  claim 33 , wherein the image processing system is configured to exclude false-positive detections, optionally obtained using one or both of the following: iv) a simulation of the gemstone to recognize edges of the diamond;
 v) imaging an outer surface of the gemstone, under illumination allowing to detect foreign particles on said outer surface.   
     
     
         35 . The system of  claim 28 , further comprising a dark-field illumination device comprising a combination of reflecting surfaces and being configured to be mounted so as to receive light from the first light source while preventing direct entry of light beams from this source into the image acquisition device. 
     
     
         36 . The system of  claim 26 , further comprising a storage system and an image processing system; the storage system including a computer memory configured to store the images at different depths along height of the gemstone; the controller further configured to compare a gemstone A to a gemstone B by:
 directing the image acquisition device to capture images at different depths along height of the gemstone for the gemstone A and the gemstone B,   storing, in the storage system, images of the gemstone A and the gemstone B from the processing system;   directing the image processing system to analyze the images for the gemstone A and the gemstone B; and   comparing the stored images of the gemstone A and the gemstone B, and determining whether the stored images of the gemstone A and the gemstone B are a match and therefore whether the gemstone B is the same gemstone as the gemstone A that was sourced from a particular mine or source.   
     
     
         37 . The system of  claim 36 , wherein if the stored images do not match, the controller is configured to calculate, based on the comparing, a matching score being informative of a match between the inclusions of gemstone A and gemstone B, and, the controller being configured to identify gemstone B as being the same or derived from gemstone A when the matching score meets a predefined matching criteria. 
     
     
         38 . A method for detecting inclusions in a gemstone, comprising a preparatory phase and a detection phase,
 the preparatory phase comprising determining parameters of each illumination pattern out of N illumination patterns each selected so as to provide an internal uniform illumination of one or more predetermined light exit regions of the gemstone, by:   (a) for each illumination pattern, selectively illuminating a plurality of spaced apart light entrance areas of the gemstone from corresponding illumination directions;   (b) for each of the illumination patterns, capturing a plurality of images of the gemstone; and   (c) processing the images to determine the parameters of each illumination pattern that provides the internal uniform illumination of the one or more predetermined light exit regions; the detection phase comprising:   (d) illuminating the gemstone successively with each one of the illumination patterns with its respective parameters and capturing a plurality of images of the gemstone for each of the illumination patterns;   (e) repeating step (d) for a plurality of depths along height of the gemstone; and (f) identify inclusions in the images based on non-uniformities in the internal illumination detected in said images.   
     
     
         39 . The method of  claim 38 , wherein, if the gemstone is a cut gemstone, the images are captured from a view point facing a table facet of the gemstone. 
     
     
         40 . The method of  claim 38 , wherein the illumination of said internal uniform illumination is based on a ray trace model being based on a 3D modelling of the gemstone. 
     
     
         41 . The method of  claim 38 , further comprising one or more of the following:
 (a) providing a mapped illustration of detected inclusions within the gemstone; (b) grading the clarity of the gemstone based on the detected inclusions.   
     
     
         42 . The method of  claim 38 , wherein said detection comprises at least one of the following:
 (a) comparing images of said predetermined light exit regions with their simulated images if these regions were illuminated uniformly;   (b) detecting differentiation of illumination intensity of said regions relative to a predetermined intensity at said regions; or   (c) using a simulation of the gemstone to recognize edges of the diamond to reduce false-positive detections.   
     
     
         43 . The method of  claim 38 , comprising performing steps (a) through (f) on a gemstone A and a gemstone B; and comparing the processed images derived from gemstone A and gemstone B to determine whether the processed images match and therefore whether the gemstone B is the same gemstone as the gemstone A that was sourced from a particular mine or source. 
     
     
         44 . The method of  claim 43 , further comprising, if the processed images do not match, calculating, based on the comparing, a matching score for the inclusions in gemstone A and the inclusions in gemstone B, the matching score being informative of a match between the inclusions in gemstone A and gemstone B; and, identifying gemstone B as being the same or derived from gemstone A, when the matching score meets a predefined matching criteria.