WO2015082985A1 - Détection de pierres précieuses synthétiques à l'aide d'un traitement d'image - Google Patents

Détection de pierres précieuses synthétiques à l'aide d'un traitement d'image Download PDF

Info

Publication number
WO2015082985A1
WO2015082985A1 PCT/IB2014/002667 IB2014002667W WO2015082985A1 WO 2015082985 A1 WO2015082985 A1 WO 2015082985A1 IB 2014002667 W IB2014002667 W IB 2014002667W WO 2015082985 A1 WO2015082985 A1 WO 2015082985A1
Authority
WO
WIPO (PCT)
Prior art keywords
gemstone
pattern
image
computing device
laser beam
Prior art date
Application number
PCT/IB2014/002667
Other languages
English (en)
Inventor
Rahul Mahendrakumar GAYWALA
Munjalkumar Dhirajlal GAJJAR
Chetan Fulchandbhai PATEL
Original Assignee
Sahajanand Technologies Pvt Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sahajanand Technologies Pvt Ltd. filed Critical Sahajanand Technologies Pvt Ltd.
Publication of WO2015082985A1 publication Critical patent/WO2015082985A1/fr

Links

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/0002—Inspection of images, e.g. flaw detection
    • G06T7/0004—Industrial image inspection
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/87—Investigating jewels
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/60—Analysis of geometric attributes
    • G06T7/68—Analysis of geometric attributes of symmetry

Definitions

  • the present subject matter relates, in general, to detecting synthetic gemstones, and in particular, to detecting synthetic gemstones using image processing.
  • diamonds are generally graded into four basic types, namely type la, lb, lla, and lib, based on amount and type of impurities that may be measured at an atomic level within a crystal lattice of carbon atoms of the diamonds, and each grade is accordingly associated with a different range of commercial value.
  • Fig. 1 illustrates a schematic view of a gemstone evaluation apparatus, in accordance with an embodiment of the present subject matter.
  • FIG. 2 illustrates a pattern generated on a screen of the gemstone evaluation apparatus, in accordance with an embodiment of the present subject matter.
  • FIG. 3 illustrates a method for detecting synthetic gemstones using image processing, in accordance with an embodiment of the present subject matter.
  • a gemstone may be understood as a piece of mineral, which, in cut and polished form, is used to make jewelry or other adornments. As gemstones are considered precious and are available at high costs, their authenticity is usually checked every time before being traded. A number of different systems and processes are known for registering and verifying the gemstones, such as diamonds, based on unique features of the gemstones, for later comparison to determine whether a gemstone purporting to be the original is indeed the original.
  • Conventional techniques for registering and verifying the gemstones typically include illuminating a gemstone, such as a polished diamond, and capturing a pattern generated by the gemstone. As each gemstone, due to its inherent properties produces a pattern upon being illuminated; the pattern is considered as a basis to verify authenticity of the gemstone. This pattern may then be stored in a database as a unique pattern for that gemstone and may be referred later.
  • a printer is deployed to print a certificate with the unique pattern and a gemstone identifier (ID) thereupon.
  • This certificate may be used for comparing the unique pattern of the gemstone with the pattern stored in the database corresponding to the gemstone ID.
  • the conventional techniques of verifying gemstones rely on the fact that no two gemstones, such as diamonds, may have a similar pattern.
  • synthetic gemstones are increasingly being produced, which appear to be similar to natural gemstones, but are man-made and are typically of lower value.
  • the conventional gemstone registration and verification techniques may not be helpful in distinguishing between synthetic and natural gemstones as the conventional techniques compare the unique pattern printed on the certificate with the pattern that may be pre-stored in the database.
  • the gemstone tested may be found to be authentic, i.e., having the same pattern as that stored in database, it may still be synthetic and not natural.
  • the present subject matter discloses aspects related to detecting synthetic gemstones using image processing techniques.
  • the present subject matter describes an apparatus and a method for examining gemstones, such as a cut, multi- faceted diamond, for detecting synthetic gemstones, such as synthetic diamonds.
  • the diamonds may be examined for one or more optical properties.
  • the apparatus may include an illumination means, such as a laser source for illuminating the gemstone with a laser beam.
  • the illumination means may be deployed at a right angle from the gemstone.
  • the apparatus may further include a gemstone holder for holding the gemstone in a pre-determined substantially upright position such that the table of the gemstone is uncovered and can be directly exposed to the laser beam.
  • the laser beam may be passed through a prism before it strikes the gemstone.
  • the laser beam is passed through the prism to turn the laser beam by 90 degrees and to increase distance at which the gemstone can be placed from the illumination means. This facilitates the impacting laser beam to cover a larger area thereby covering the entire table of gemstone.
  • the apparatus may include a screen on which a reflection/refraction pattern produced by the gemstone when exposed to the laser beam can be projected.
  • An image of the pattern is captured by an image capturing device mounted opposite to the screen.
  • the image capturing device may be coupled to a computing device for processing the captured image of the reflection/refraction pattern.
  • the computing device may employ at least one image processing technique on the image received by the image capturing device to determine the authenticity of the gemstone.
  • an image processing technique may facilitate in converting the image to a black and white image so that all white spots can be detected from the black and white image. Further, by applying the image processing techniques, the computing system may determine co-ordinates of the white spots.
  • the pre-defined calibrated image centre- point may be understood as a rotation centre point of gemstone pattern obtained on the screen.
  • the machine is aligned in such a way that distance between each spot and centre point is not changed when the gemstone is rotated.
  • the gemstone is illuminated by the laser beam after the laser beam passes through the prism.
  • the laser beam upon striking the gemstone may get reflected and may create a pattern on the screen.
  • the pattern may be unique for each gemstone.
  • the pattern may be formed as a plurality of spots on the screen.
  • This pattern may be captured by the image capturing device in the form of an image and provided to the computing device for further processing.
  • the computing device may apply one or more image processing techniques on the captured image to determine co-ordinates of these white spots, as described above. Based on these co-ordinates a final pattern of the image is obtained.
  • the final pattern may be understood as the co-ordinates of the white spots obtained upon application of image processing techniques.
  • the gemstone being analyzed may be considered as a synthetic or man made gemstone.
  • the percentage of presence of symmetrical gaps and the minimum degree of rotation of gaps for ascertaining the authenticity of the polished diamonds has been derived on the basis of analysis of more than 50,000 synthetic and natural gemstones.
  • the symmetrical gaps may be understood as the gaps that are located at equal rotation degree from each other.
  • the gemstones may be considered as real gemstones.
  • the present subject matter provides a quick and inexpensive technique for detecting synthetic gemstones using image processing. This may provide an accurate examination of a gemstone for true price valuation of the gemstone. Further, the present subject matter facilitates in reducing theft of gemstones and providing actual value of the money to end-users.
  • Fig. 1 illustrates a schematic view of a gemstone evaluation apparatus 100 (hereinafter referred as apparatus 100), in accordance with an embodiment of the present subject matter.
  • the apparatus 100 may be configured to use image processing techniques for detecting synthetic gemstones.
  • the apparatus 100 may include a gemstone holder (not shown) for holding a gemstone, such as a diamond 102.
  • the gemstone holder may be configured to hold and automatically position the diamond 102 in a pre-determined upright position in which the table of the diamond 102 is uncovered and directly exposed to each light ray.
  • the gemstone holder may be configured to orient the diamond 102 in such a way that the table of the diamond 102 becomes perpendicular to a radiation beam.
  • the apparatus 100 may include an illumination means 104, such as a laser source.
  • the illumination means 104 may be mounted in a holder (not shown).
  • the illumination means 104 may be disposed at a right angle from the diamond 102.
  • the illumination means 104 may be configured to illuminate the diamond 102 with a laser beam 106.
  • the laser beam 106 may pass through a prism 108, before striking the diamond 102.
  • the prism 108 may be mounted in a prism holder (not shown).
  • the apparatus 1 00 may include a screen 1 10 to project a pattern of scattered laser beam 106 due to reflection of the laser beam 106 from the diamond 102.
  • the screen 1 10 may be located between the diamond 102 and the prism 108.
  • the apparatus 100 may include an image capturing device 1 12 placed opposite to the diamond 102.
  • the image capturing device 1 12 may be a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) device.
  • CCD charge coupled device
  • CMOS complementary metal oxide semiconductor
  • the prism 108 may be positioned such that the diamond 102 and the screen 1 10 are at one side of the prism 108 and the image capturing device 1 12 is at the other side of the prism 108, Further, the image capturing device 1 12 may be adjusted to cover reflection and/or refraction pattern of the laser beam 106 on the screen 1 10. [0021] Further, an output of the image capturing device 1 12 may be fed to a computing device 1 14 for further analysis. It will be evident that the computing device 1 14 may include a memory, an interface, a keyboard, and a processor. The processor can be a single processing unit or a number of units, all of which could also include multiple computing units.
  • the processor may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, state machines, logic circuitries, and/or any devices that manipulate signals based on operational instructions.
  • the processor is configured to fetch and execute computer-readable instructions and data stored in the memory.
  • the computing device 1 14 may further include modules.
  • the module(s) include routines, programs, objects, components, data structures, etc., which perform particular tasks or implement particular abstract data types.
  • the module(s) includes a pattern identification module and an evaluation module.
  • the computing device 1 14 may simplify the image to a monochromatic display by applying various corrections to the image.
  • the computing device 1 14 may apply various image processing techniques on the image of the pattern obtained as the output from the image capturing device 1 12.
  • the pattern identification module may receive an image of a pattern of the gemstone 102. The pattern may be created on the screen 1 10 on reflection of the laser beam 106. In an example, the pattern includes a plurality of spots. The pattern identification module may convert the image to a black and white image. Thereafter, the pattern identification module may detect white spots in the black and white image. The pattern identification module may apply at least one image processing technique to identify co-ordinates of the plurality of spots in the image.
  • the pattern identification module may subtract the co-ordinates of these white spots from a pre-defined calibrated image centre point.
  • the pre-defined calibrated image centre-point may be understood as a rotation centre point of gemstone patterns plotted on a screen. As each machine has its own centre point, the machine is aligned in such a way that distance between each spot and centre point is not changed when the gemstone is rotated. After the subtraction, a final pattern of the diamond 102 is obtained.
  • the evaluation module of the computing device 1 14 may identify if there are any symmetrical gaps in an outer area of the final pattern. In an example, the outer area may be understood as a circumference of the pattern created on the screen.
  • the term 'symmetrical gaps' may indicate that each gap is located on equal rotation degree from each other.
  • the gemstone 102 may be considered as a synthetic gemstone.
  • the symmetrical gaps may cover about 40%-60% of the circumference of the final pattern. In case either of the two conditions, i.e., presence of symmetrical gaps in 50% outer area of the pattern or minimum degree of rotation of these gaps between 12 to 24 is satisfied, the gemstone 102 may be considered as real or natural gemstone.
  • the pattern 200 includes a plurality of black spots 202 as a result of the refraction or reflection of the laser beam 106 by the diamond 102.
  • the image capturing device 1 12 may capture an image of the pattern 200 and provide that image as an input to the computing device 1 14.
  • the computing device 1 14 may employ at least one image processing technique to convert the image to a black and white image.
  • the black and white image may include a plurality of white spots (hereinafter referred to as gaps 204-1 , 204-2...204-N, collectively referred to as gaps 204 and individually referred to as gap 204.
  • the computing device 1 14 may compute coordinates of the gaps 204.
  • the co-ordinates of the gaps 204 may be determined on the basis of the co-ordinates of the white spots or the final pattern. Thereafter, the coordinates of the gaps 204 are subtracted from a pre-defined calibrated image centre point to get a final pattern of the gemstone.
  • the diamond 102 being analyzed may be considered as a man-made or synthetic diamond.
  • the gemstones 102 may be considered as real gemstones.
  • the symmetrical gaps may be understood as the gaps that are located on equal rotation degree from each other.
  • the method 300 can be implemented in any suitable hardware, software, firmware, or combination thereof.
  • one or more of the method(s) described herein may be implemented at least in part as instructions embodied in a non-transitory computer-readable medium and executable by one or more computing devices.
  • a processor for example a microprocessor
  • Such instructions may be stored or transmitted using any of a variety of known computer-readable media.
  • a gemstone such as diamond 102
  • a laser beam such as the laser beam 106.
  • the diamond 102 is received in a gemstone holder of the apparatus 100. It will be understood that the diamond 102 may be provided by a user.
  • the apparatus 100 may include an automatic feeding mechanism (not shown) for placing the diamond 102 in the gemstone holder.
  • the gemstones may be illuminated by the light source as described above.
  • structural light triangulation method may be used for illuminating the gemstones with a predefined pattern of light/laser. When such pattern of the light/laser strikes the gemstones, the beam of light may get interrupted.
  • the method 300 may include capturing a pattern, such as pattern 200, displayed on a screen, such as the screen 1 10 of the apparatus 100, as a result of the reflection of the laser beam 106 from the diamond 102.
  • the image capturing device 1 12 such as a Charge Coupled Device (CCD) and a Complementary Metal Oxide Semiconductor (CMOS) device, may capture the pattern 200 of the diamond 102.
  • CCD Charge Coupled Device
  • CMOS Complementary Metal Oxide Semiconductor
  • the method 300 may include providing the captured pattern to the computing device 1 14 for image processing.
  • an output of the image capturing device 1 12 may be fed to the computing device 1 14.
  • the computing device 1 14 may apply one or more image processing techniques on the captured pattern 200.
  • the computing device 1 14 may convert the image of the pattern 200 into a black and white image.
  • the computing device 1 14 may detect white spots in the black and white image.
  • the computing device 1 14 may identify co-ordinates of the white spots which are then subtracted from a pre-defined calibrated image centre point. Thereafter, a final pattern of the gemstone 102 may be obtained.
  • the method 300 may include identifying whether there are any symmetrical gaps in an outer area of the pattern.
  • the computing device 1 14 may analyze the final pattern to identify whether symmetrical gaps are present in more than 50% of the outer area.
  • the symmetrical gaps 204 may mean that each gap in the final pattern is located on equal rotation degree from each other. If it is identified that the there are no symmetrical gaps in the outer area of the final pattern, the diamond 102 may be considered as a natural or real diamond, as shown in block 310. On the other hand, if there are symmetrical gaps in outer area of the pattern, the method 300 may move to block 3 12.
  • the method 300 may include determining if a minimum degree of rotation of the symmetrical gaps is between 1 2 to 24.
  • the computing device 1 14 may determine the degree of rotation of the symmetrical gaps. If the minimum degree of rotation of the symmetrical gaps is not between 12 to 24, the method 300 may move to block 310 to indicate that the diamond 102 is natural.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geometry (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Quality & Reliability (AREA)
  • Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)

Abstract

L'invention concerne un appareil et un procédé pour détecter des pierres précieuses synthétiques à l'aide d'un traitement d'image. L'appareil comprend un moyen d'éclairage (104) pour éclairer une pierre précieuse (102) par un faisceau laser (106). Lorsque le faisceau laser (106) atteint la pierre précieuse (102), un modèle de réflexion/réfraction est produit sur un écran (110). Une image du modèle de réflexion est capturée par un dispositif de capture d'image (112) monté à l'opposé de l'écran (110). L'image est acheminée à un dispositif informatique (114) pour traiter l'image capturée pour déterminer une pluralité de points blancs. En outre, des coordonnées de ces points blancs sont identifiées et, sur la base de ces coordonnées, un modèle final de l'image est obtenu. Le modèle final de la pierre précieuse (102) est analysé pour identifier si la pierre précieuse (102) est synthétique.
PCT/IB2014/002667 2013-12-05 2014-12-05 Détection de pierres précieuses synthétiques à l'aide d'un traitement d'image WO2015082985A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IN3810/MUM/2013 2013-12-05
IN3810MU2013 IN2013MU03810A (fr) 2013-12-05 2014-12-05

Publications (1)

Publication Number Publication Date
WO2015082985A1 true WO2015082985A1 (fr) 2015-06-11

Family

ID=52345471

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2014/002667 WO2015082985A1 (fr) 2013-12-05 2014-12-05 Détection de pierres précieuses synthétiques à l'aide d'un traitement d'image

Country Status (2)

Country Link
IN (1) IN2013MU03810A (fr)
WO (1) WO2015082985A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017085730A1 (fr) * 2015-11-19 2017-05-26 Dayalbhai Goti Shailesh Appareil et procédé d'identification de diamants synthétiques
US10942128B2 (en) 2016-10-24 2021-03-09 Tomra Sorting Gmbh Method and system for detecting a diamond signature

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3947120A (en) * 1973-10-23 1976-03-30 Yeda Research And Development Co. Ltd. Gem identification
US5883389A (en) * 1993-03-05 1999-03-16 Spear; Paul Martyn Distinguishing natural from synthetic diamonds
US20010023925A1 (en) * 1995-07-24 2001-09-27 Smith Martin Phillip Examining a diamond

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3947120A (en) * 1973-10-23 1976-03-30 Yeda Research And Development Co. Ltd. Gem identification
US5883389A (en) * 1993-03-05 1999-03-16 Spear; Paul Martyn Distinguishing natural from synthetic diamonds
US20010023925A1 (en) * 1995-07-24 2001-09-27 Smith Martin Phillip Examining a diamond

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
ANONYMOUS: "GCAL - HOW DOES GEMPRINT WORK?", 1 January 2008 (2008-01-01), pages 1, XP055176667, Retrieved from the Internet <URL:http://www.diamondid.com/pages/SAFE_REGISTER/GEMPRINT/Gemprint_HOW_DOES_GEMPRINT_WORK.html> [retrieved on 20150316] *
RUSSEL SHOR: "Synthetic Diamonds: How Many Are Out There?", 26 August 2013 (2013-08-26), pages 1 - 3, XP055176711, Retrieved from the Internet <URL:http://www.gia.edu/research-news-synthetic-diamonds-how-many-there> [retrieved on 20150316] *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017085730A1 (fr) * 2015-11-19 2017-05-26 Dayalbhai Goti Shailesh Appareil et procédé d'identification de diamants synthétiques
US10942128B2 (en) 2016-10-24 2021-03-09 Tomra Sorting Gmbh Method and system for detecting a diamond signature

Also Published As

Publication number Publication date
IN2013MU03810A (fr) 2015-08-07

Similar Documents

Publication Publication Date Title
JP6447637B2 (ja) 表面欠陥検出装置、表面欠陥検出方法、及び鋼材の製造方法
JP6629455B2 (ja) 外観検査装置、照明装置、撮影照明装置
US9940515B2 (en) Image analysis for authenticating a product
JP6394514B2 (ja) 表面欠陥検出方法、表面欠陥検出装置、及び鋼材の製造方法
JP2018521377A (ja) 人工３ｄ再構成を用いてセキュリティパターンを識別する方法
JP5393479B2 (ja) 物体の検査方法及び検査装置
KR20190098262A (ko) 심층적으로 적층된 층들을 갖는 웨이퍼들에서 결함 분류기를 트레이닝하고 적용하기 위한 시스템, 방법
US20200232934A1 (en) Multi-perspective wafer analysis
US11176651B2 (en) Computer-controlled 3D analysis of collectible objects
US6864971B2 (en) System and method for performing optical inspection utilizing diffracted light
JP2021047200A (ja) 表面特性を決定する多段階方法および調査装置
WO2020079694A1 (fr) Optimisation de la détection de défauts dans un processus d&#39;inspection visuelle automatique
JP5635700B2 (ja) ダイヤモンドのハート＆キューピッド光学効果の良否判定方法及びその装置
WO2015082985A1 (fr) Détection de pierres précieuses synthétiques à l&#39;aide d&#39;un traitement d&#39;image
US20120268728A1 (en) Gem positioning and analysis system
US11959796B1 (en) Estimating gemstone weight in mounted settings
JP2023073399A (ja) 評価方法及び評価システム
US11327026B1 (en) Comparing gemstone signatures using angular spectrum information
US20230222641A1 (en) Method and apparatus for identifying characteristics of trading cards
US20100033708A1 (en) Optical Inspection System Using UV Light for Automated Inspection of Holograms
CN114663341A (zh) 一种光学镜头眩光缺陷定量检测方法
JP2008224540A (ja) 歪み検査方法および検査装置
US10341555B2 (en) Characterization of a physical object based on its surface roughness
US20230408419A1 (en) Digital image gemstone verification with filters
WO2021193013A1 (fr) Dispositif de génération d&#39;informations de caractéristique, dispositif d&#39;identification de pièce de monnaie, système de génération d&#39;informations de caractéristique, procédé de génération d&#39;informations de caractéristique et programme de génération d&#39;informations de caractéristique

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14825434

Country of ref document: EP

Kind code of ref document: A1

DPE1 Request for preliminary examination filed after expiration of 19th month from priority date (pct application filed from 20040101)
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 14825434

Country of ref document: EP

Kind code of ref document: A1