Apparatus for determining authenticity of artwork through crack analysis based on optical coherence tomography

Abstract

The present invention relates to an apparatus for determining the authenticity of an artwork through a crack analysis based on optical coherence tomography, the apparatus for determining the authenticity of an artwork through a crack analysis based on optical coherence tomography, according to one aspect of the present invention, being for obtaining an optical coherence tomography image of a crack, which is generated by performing optical coherence tomography on an area including the crack on the surface of an artwork, extracting a cross-sectional image of a surface intersecting the crack from the optical coherence tomography image, and determining the authenticity of the artwork on the basis of the shape of the crack in the cross-sectional image.

Description

Artwork Authenticity Verification Device via Crack Analysis Based on Optical Coherence Tomography

[0001] The present invention relates to a technology for determining the authenticity of a work of art.

[0002] The present invention is derived from research conducted as part of the National Research Foundation of Korea’s Future Defense Innovation Technology Development Project, funded by the government (Ministry of Science and ICT) [Project No.: 2710082868, Research Project Title: Securing Technology Based on Customized Linear Polarization Devices and Development of Polarization Cameras for Surveillance / Reconnaissance].

[0003] The present invention is derived from research conducted as part of the National Research Foundation of Korea’s Talent Utilization and Dissemination Support Program, funded by the government (Ministry of Science and ICT) [Project No.: 2710068982, Research Project Title: International Joint Research Group on Quantum-Bio Convergence Nanophotonics].

[0004] In the international art market, the number of transactions and transaction values ​​of artworks are generally increasing, despite some fluctuations. This is attributed to rising public interest and demand for art, as well as a growing awareness of the cultural and financial value of artworks.

[0005] Meanwhile, art forgery scandals driven by financial gain are occurring, and forgery technology is rapidly advancing. Since forged artworks can undermine the credibility of the art market and cause economic disruption, the development of specialized technology to distinguish authenticity is necessary to support artists' activities and facilitate smooth transactions within the market.

[0006] Traditionally, the determination of authenticity in artworks has primarily been made through visual inspection by insightful experts. However, this existing method presents challenges, such as potential variations in accuracy depending on the expert, and the difficulty of identifying forgeries as forgery techniques become increasingly sophisticated.

[0007] To solve the above problem, Korean Patent Application No. 10-2015-0084407 discloses a technology for appraising the authenticity of artworks by analyzing the surface curvature shape of the artworks through coherent interference tomography. This existing technology has the problem of requiring a long time for imaging and data processing because it requires extensive imaging of the artwork's surface.

[0008] According to recent research, cracks in painted surfaces contain information about unique characteristics, such as environmental factors and pigment ratios, suggesting that these cracks can be utilized to determine the authenticity of artworks. Existing crack analysis techniques, which involve extracting and analyzing pigments from artworks, suffer from the problem of causing irreversible damage to the original pieces.

[0009] A case has been disclosed in which natural cracks and forged cracks were successfully distinguished by magnifying the crack shape using a microscope that provides high-magnification images. While this existing technique enables rapid analysis, it has the limitation of observing only the upper surface of the crack.

[0010] The objective of the present invention is to solve the aforementioned problem by determining the authenticity of an artwork by analyzing the cross-sectional shape of a crack formed on the surface of the artwork based on optical coherence tomography.

[0011] The present invention aims to determine the authenticity of an artwork by analyzing crack characteristics caused by the ratio of paint and medium through the cross-sectional shape of the crack, without causing physical damage to the artwork.

[0012] The objectives of the present invention are not limited to those mentioned above, and other unmentioned objectives will be clearly understood from the description below.

[0013] An apparatus for determining the authenticity of an artwork through crack analysis based on optical coherence tomography according to one aspect of the present invention for achieving the aforementioned purpose comprises a communication unit, a memory for storing preset commands, and a processor connected to the communication unit and the memory and executing a process for determining the authenticity of an artwork as the commands are executed. The processor obtains an optical coherence tomography image of a crack generated by optical coherence tomography of an area containing a crack on the surface of an artwork from an external device through the communication unit, extracts a cross-sectional image of a plane intersecting the crack from the optical coherence tomography image, and determines the authenticity of the artwork according to the shape of the crack in the cross-sectional image.

[0014] According to the present invention, by analyzing the cross-sectional shape of a crack formed on the surface of an artwork based on optical coherence tomography, it has the effect of quickly and accurately determining the authenticity of the artwork.

[0015] According to the present invention, by analyzing the crack characteristics caused by the combination ratio of paint and medium through the cross-sectional shape of the crack, there is an effect of enabling the determination of authenticity based on definite and specific grounds.

[0016] In other words, it is possible to expect the effect of accurately determining authenticity based on the characteristics according to the ratio of pigment in the cracks, without extracting pigments that physically damage the artwork.

[0017] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims.

[0018] FIG. 1 is a conceptual diagram showing the crack shape measurement and authenticity determination process of an art authenticity determination device based on optical coherence tomography crack analysis according to an embodiment of the present invention.

[0019] FIG. 2 is a block diagram of an art authenticity determination device based on optical coherence tomography crack analysis according to an embodiment of the present invention.

[0020] FIG. 3 is a flowchart of the operation of a device for determining the authenticity of artwork through crack analysis based on optical coherence tomography according to an embodiment of the present invention.

[0021] Figure 4 is a drawing showing the surface shape of each crack included in the genuine and counterfeit versions of Artwork 1.

[0022] Figure 5 is a drawing showing the surface shape of each crack included in the genuine and counterfeit versions of Artwork 2.

[0023] Figure 6 is a diagram showing cross-sectional images of each crack included in the genuine and counterfeit products of Figure 4.

[0024] Figure 7 is a diagram showing cross-sectional images of each crack included in the genuine and counterfeit products of Figure 5.

[0025] Figure 8 is a table summarizing the results of analyzing the shape of the cracks in the cross-sectional images of each crack in Figure 6.

[0026] Figure 9 is a table summarizing the results of analyzing the shape of the cracks in the cross-sectional images of each crack in Figure 7.

[0027] Figure 10 is a graph showing the crack width values ​​calculated from the cross-sectional images of each crack in Figures 6 and 7.

[0028] Figure 11 is a graph showing the crack depth values ​​calculated from the cross-sectional images of each crack in Figures 6 and 7.

[0029] Figure 12 is a graph showing the width value relative to the depth value of the crack calculated from the cross-sectional images of each crack in Figures 6 and 7.

[0030] Figure 13 is a graph showing the ratio of the width value to the depth value of the crack calculated from the cross-sectional images of each crack in Figures 6 and 7.

[0031] An apparatus for determining the authenticity of an artwork through crack analysis based on optical coherence tomography according to one aspect of the present invention for achieving the aforementioned purpose comprises a communication unit, a memory for storing preset commands, and a processor connected to the communication unit and the memory and executing a process for determining the authenticity of an artwork in accordance with the execution of the commands. The processor obtains an optical coherence tomography image of a crack generated by optical coherence tomography of an area containing a crack on the surface of an artwork from an external device through the communication unit, extracts a cross-sectional image of a plane intersecting the crack from the optical coherence tomography image, and determines the authenticity of the artwork according to the shape of the crack in the cross-sectional image.

[0032] The advantages and features of the present invention, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the claims. Meanwhile, the terms used in this specification are for describing the embodiments and are not intended to limit the present invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text.

[0033] The present invention relates to a technology for determining the authenticity of an artwork by analyzing cracks formed on the surface of an oil painting based on optical coherence tomography.

[0034] In particular, the present invention is characterized by the technical feature of being able to accurately and quickly distinguish between genuine and counterfeit products through the shape of the crack cross-section, and to determine authenticity based on evidence of crack characteristics caused by the combination ratio of paint and medium without pigment extraction.

[0035] Referring to FIG. 1, these technical features can be achieved by a configuration that obtains a three-dimensional optical coherence tomography image generated by optical coherence tomography of a crack-containing area in an original artwork and a forgery, extracts a cross-sectional image intersecting the crack from the three-dimensional optical coherence tomography image, and determines authenticity based on the width and depth of the crack in the extracted cross-sectional image.

[0036] Referring to FIG. 2, an art authenticity determination device (100) based on optical coherence tomography crack analysis according to an embodiment of the present invention may be configured to include a communication unit (110), a memory (120), and a processor (130).

[0037] The communication unit (110) may be connected to communicate with an external SD-OCT system (10) and receive an optical coherence tomography image of a crack generated by optical coherence tomography of an area containing a crack on the surface of an artwork from the SD-OCT system (10).

[0038] Here, the SD-OCT system (10) may perform optical coherence tomography on areas containing cracks on the surface of the artwork according to user input and generate a three-dimensional optical coherence tomography image for each crack contained on the surface of the artwork.

[0039] The memory (120) includes a computer-readable recording medium and may store instructions configured to perform an operating system and an art authenticity determination process according to an embodiment of the present invention.

[0040] The processor (130) is connected to the communication unit (110) and the memory (120), and may execute the process of determining the authenticity of artwork by executing commands stored in the memory (13) as it performs basic arithmetic, logic, and input / output operations.

[0041] Referring to FIG. 3, the processor (130) obtains an optical coherence tomography image of a crack created by optical coherence tomography of an area containing a crack on the surface of an artwork from the outside through the communication unit (110) (S110), and can extract a cross-sectional image of a plane intersecting the crack from the optical coherence tomography image (S120).

[0042] At this time, the processor (130) may extract a cross-sectional image of a plane perpendicular to a line at a preset position (e.g., center) from a line formed by points corresponding to the crack formed on the surface of the artwork in a three-dimensional optical coherence tomography image of the crack (S120).

[0043] Afterward, the processor (130) may determine the authenticity of the artwork based on the shape of the crack in the cross-sectional image (S130).

[0044] Figure 4 shows an enlarged image of cracks observed on the surface of the original artworks and forgery of Artwork 1, where the ratio of medium to paint is larger in the upper part compared to the lower part of the artwork, and Figure 5 shows an enlarged image of cracks observed on the surface of the original artworks and forgery of Artwork 2, where the ratio of medium to paint is larger in the lower part compared to the upper part of the artwork.

[0045] Medium is an art material used to mix with paint to control its consistency, gloss, and other properties, enabling a wide range of expressions.

[0046] Referring to Fig. 4, when the ratio of medium to paint is greater in the upper part of the artwork than in the lower part, it can be seen that cracks (aⅠ, aⅡ, aⅢ) created by natural drying in the genuine artwork and cracks (bⅠ, bⅡ, bⅢ) created by artificial drying in the counterfeit artwork both have a common width of cracks formed wide enough to allow the color of the lower paint layer to be observed on the surface.

[0047] And, referring to Fig. 5, when the ratio of medium to paint is greater in the lower part of the artwork than in the upper part, it can be seen that the cracks (cⅣ, cⅤ, cⅥ) created by natural drying in the genuine artwork and the cracks (dⅣ, dⅤ, dⅥ) created by artificial drying in the counterfeit artwork both have a common characteristic of forming thin cracks so that the color of the lower paint layer is not visible on the surface.

[0048] In other words, cracks formed on the surface of the artwork exhibit specific crack characteristics depending on the ratio of medium to paint in the lower and upper parts of the artwork, and when the crack characteristics are identical, it was difficult to identify features in magnified images of the cracks that could distinguish between the genuine and the forged.

[0049] Referring to FIGS. 6 and FIGS. 7, it can be seen that the cracks (aⅠ, aⅡ, aⅢ, bⅠ, bⅡ, bⅢ) of Artwork 1, which have a first crack characteristic where the ratio of medium to paint as shown in FIG. 4 is greater in the upper part than in the lower part of the artwork, have a smaller top width compared to the cracks (cⅣ, cⅤ, cⅥ, dⅣ, dⅤ, dⅥ) of Artwork 2, which have a second crack characteristic where the ratio of medium to paint as shown in FIG. 5 is greater in the lower part than in the upper part of the artwork. Accordingly, it can be seen that there are differences in the width and aspect ratio of the cracks depending on the crack characteristic, in that the aspect ratio, which is the ratio of width to depth, is large.

[0050] In addition, referring to the genuine part of Fig. 6, the cracks (aⅠ, aⅡ, aⅢ) generated by natural drying observed in the genuine part of Fig. 4 have a flat rectangular shape at the bottom of the cracks and clean sides, whereas referring to the counterfeit part of Fig. 6, the cracks (bⅠ, bⅡ, bⅢ) generated by artificial drying observed in the counterfeit part of Fig. 4 have uneven sides with a shape that narrows in width as it goes downwards.

[0051] Referring to the genuine part of Fig. 7, it can be seen that the cracks (cⅣ, cⅤ, cⅥ) generated by natural drying observed in the genuine part of Fig. 5 have a thin rectangular shape with a small width and deep depth, whereas referring to the counterfeit part of Fig. 7, the cracks (dⅣ, dⅤ, dⅥ) generated by artificial drying observed in the counterfeit part of Fig. 5 have an inverted triangular shape with a small width and shallow depth.

[0052] Referring to FIGS. 8 to 10, it can be seen that the cracks (I, II, III) of Artwork 1 have a smaller width at the top compared to the cracks (IV, V, VI) of Artwork 2, and that the cracks (I, II, III) corresponding to the genuine work in Artwork 1 have the same width value at the top, middle, and bottom, whereas the cracks (I, II, III) corresponding to the counterfeit work in Artwork 1 having the first crack characteristic have different width values ​​at the top, middle, and bottom.

[0053] Referring to Fig. 11, it can be seen that when the crack characteristics are the same, the genuine and counterfeit can be distinguished based on the depth value, as the cracks (I, II, III) of Artwork 1 have a greater depth value in the genuine than the counterfeit, and the cracks (IV, V, VI) of Artwork 2 have a greater depth value in the counterfeit than the genuine. However, when genuine and counterfeit items with different crack characteristics are mixed, it is difficult to distinguish the crack characteristics or authenticity based on a specific threshold using the depth value.

[0054] Referring to Figures 12 and 13, the value obtained by dividing the width value by the depth value (W / D) and the value obtained by dividing the depth value by the width value (D / W) can distinguish between genuine and counterfeit products based on a specific threshold value when the crack characteristics are identical, just like the depth value; however, it can be seen that when genuine and counterfeit products with different crack characteristics are mixed, it is difficult to distinguish between genuine and counterfeit products or to distinguish the crack characteristics based on a specific threshold value.

[0055] In summary, regardless of whether the artwork is genuine or a forgery, there were significant differences in the width of cracks formed on the surface of the artwork according to the first crack characteristic, where the ratio of medium to paint is greater in the upper part compared to the lower part, and the second crack characteristic, where the ratio of medium to paint is greater in the lower part compared to the upper part. Additionally, it was confirmed that for the same crack characteristics, there were significant differences in width and depth values ​​at different vertical and horizontal positions depending on the authenticity of the artwork.

[0056] Based on the results of analyzing the characteristics of the crack shape according to the crack characteristics described above and the characteristics of the crack shape according to the authenticity of specific crack characteristics, the present invention classifies crack characteristics according to the top width of the crack in a cross-sectional image and determines the authenticity of the artwork based on width values ​​and depth values ​​according to the classified crack characteristics.

[0057] Therefore, by determining the authenticity of artworks using quantitative figures based on criteria that present specific and solid grounds for special cases caused by raw material ratios, it is possible to provide accurate and reliable technology for determining the authenticity of artworks.

[0058] Specifically, the processor (130) may detect a crack area corresponding to a crack in a cross-sectional image (S131) ​​and calculate a width value for the horizontal length of the crack area and a depth value for the vertical length of the crack area (S133).

[0059] At this time, the processor (130) can detect a crack area corresponding to a crack based on the difference in pixel values ​​using a preset image processing algorithm (S131).

[0060] And, the processor (130) may calculate width values ​​for the horizontal length of the crack area at different vertical positions (top, center, bottom) and depth values ​​for the vertical length of the crack area at different horizontal positions (left, center, right) as the crack area is divided into a preset number (e.g., 3) in the horizontal and vertical directions (S133).

[0061] Afterward, the processor (130) may classify the crack characteristics into one of the preset crack characteristics based on the ratio of medium to paint, based on the calculated width and depth values ​​(S135).

[0062] Here, the preset crack characteristics may include a preset first crack characteristic, which means that the ratio of medium to paint is greater in the upper part of the artwork than in the lower part, and a preset second crack characteristic, which means that the ratio of medium to paint is greater in the lower part of the artwork than in the upper part.

[0063] The processor (130) may classify the width value for the top vertical position among the calculated width values ​​as a first crack characteristic if it exceeds a preset threshold value, and classify it as a second crack characteristic if it does not exceed a preset threshold value (S135).

[0064] And, the processor (130) may determine whether the width and depth values ​​calculated from each crack satisfy a preset standard for the crack characteristics classified, whether it is genuine or counterfeit (S137).

[0065] The processor (130) may determine that the product is genuine if the amount of change in width values ​​for different vertical positions calculated is within a preset threshold, and determine that the product is counterfeit if the amount of change in width values ​​for vertical positions exceeds a preset threshold (S137).

[0066] Here, the processor (130) may determine that the product is genuine if the variance of the width values ​​for different vertical positions calculated is within a preset threshold, and that it is a counterfeit if it exceeds the threshold (S137).

[0067] According to the above configuration, the processor (130) can determine that a genuine work is one in which the cross-section of the crack is rectangular and there is almost no change in the width of the crack, and that a counterfeit work is one in which the cross-section of the crack is in the shape of an inverted triangle and there is a relatively large change in the width of the crack, in a first crack characteristic where the ratio of medium to paint is greater in the upper part of the work compared to the lower part of the work.

[0068] The processor (130) may determine whether it is genuine or counterfeit based on whether the aspect ratio, which is the ratio of the largest width value among the calculated width values ​​and the largest depth value among the calculated depth values, is within a preset threshold value when classified into a second crack characteristic according to the classified crack characteristic (S137).

[0069] When classified by a preset second crack characteristic, the processor (130) may determine that the product is genuine if the aspect ratio calculated by dividing the largest depth value among the depth values ​​by the largest width value among the width values ​​exceeds a preset threshold, and determine that the product is counterfeit if the aspect ratio does not exceed a preset threshold (S137).

[0070] According to the above configuration, the processor (130) can determine that a genuine work is genuine if it has a rectangular shape with a significantly larger depth-to-width ratio in the cross-section of the crack in a second crack characteristic where the ratio of medium to paint is greater in the lower part of the work than in the upper part of the work, and can determine that a counterfeit work is counterfeit if it has an inverted triangle shape with a smaller depth-to-width ratio in the cross-section of the crack than in the genuine work.

[0071] According to the present invention, the cross-sectional shape of a crack formed on the surface of an artwork is confirmed based on optical coherence tomography, and the authenticity of the artwork can be determined based on the cross-sectional shape of the crack.

[0072] By utilizing optical coherence tomography images of only specific areas containing cracks on the artwork's surface, rather than the entire surface, it offers the advantage of increasing accuracy through cross-sectional shapes while reducing computational load and processing time.

[0073] In particular, based on the results of a quantitative analysis of crack shapes of genuine and counterfeit artworks corresponding to two crack characteristics according to the ratio of medium to paint, the present invention first classifies crack characteristics according to the width of the cracks, and determines authenticity based on the width and depth of the cracks according to the classified crack characteristics.

[0074] In other words, the present invention provides clear and detailed grounds for determining authenticity, enabling the identification of genuine and counterfeit works with high reliability and accuracy based on quantitative figures.

[0075] Meanwhile, the blocks of the attached block diagram and the steps of the flowchart may be implemented as computer instructions that perform specified functions by being loaded into the processor or memory of an electronic device capable of data processing (e.g., a general-purpose computer, a specialized computer, a portable notebook computer, or a network computer). Since these computer program instructions can be stored in computer-readable memory, the functions described in the blocks of the block diagram or the steps of the flowchart may be produced as manufactured products containing means of instruction to perform them.

[0076] A person skilled in the art to which the present invention pertains will understand that the present invention may be implemented in other specific forms without altering its technical concept or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims set forth below rather than by the detailed description above, and all modifications or variations derived from the claims and their equivalents should be interpreted as being included within the scope of the present invention.

[0077] The present invention relates to a technology for determining the authenticity of a work of art.

Claims

1. Communications Department; Memory for storing preset commands; and A processor connected to the communication unit and the memory and executing a process for determining the authenticity of artwork by performing the commands; comprising The above processor By obtaining an optical coherence tomography image of a crack generated by optical coherence tomography of an area containing a crack on the surface of an artwork from an external device through the above communication unit, A cross-sectional image of the plane intersecting the crack is extracted from the above optical interference tomography image, and Determining the authenticity of an artwork based on the shape of the crack in the cross-sectional image above. Artwork authenticity determination device through crack analysis based on optical coherence tomography.

2. In Paragraph 1, The above processor Detect a crack region corresponding to a crack in the cross-sectional image above, and In the above crack area, the width value for the horizontal length and the depth value for the vertical length of the above crack area are calculated, Based on the calculated width value, the crack characteristics are classified into one of the preset crack characteristics according to the ratio of medium to paint, and Determining whether it is genuine or counterfeit based on whether the calculated width and depth values ​​satisfy pre-established criteria for classified crack characteristics. Artwork authenticity determination device through crack analysis based on optical coherence tomography.

3. In Paragraph 2, The above processor Classifying the crack characteristic into either a pre-set first crack characteristic, meaning that the ratio of medium to paint is greater in the upper part of the artwork than in the lower part, or a pre-set second crack characteristic, meaning that the ratio of medium to paint is greater in the lower part of the artwork than in the upper part, depending on whether the calculated width value exceeds a pre-set threshold. Artwork authenticity determination device through crack analysis based on optical coherence tomography.

4. In Paragraph 3, The above processor Calculating width values ​​for the horizontal length of the crack area at different vertical positions and depth values ​​for the vertical length of the crack area at different horizontal positions, by dividing the crack area into a predetermined number of horizontal and vertical positions. Artwork authenticity determination device through crack analysis based on optical coherence tomography.

5. In Paragraph 4, The above processor Based on the width value for the uppermost vertical position among the calculated width values, classifying it as a preset first crack characteristic if it exceeds a preset threshold and as a second crack characteristic if it does not exceed a preset threshold. Artwork authenticity determination device through crack analysis based on optical coherence tomography.

6. In Paragraph 4, The above processor When classified according to the classified crack characteristics, determining whether it is genuine or counterfeit based on whether the amount of change in width values ​​for different vertical positions calculated is within a preset threshold. Artwork authenticity determination device through crack analysis based on optical coherence tomography.

7. In Paragraph 4, The above processor When classified into a preset second crack characteristic according to the classified crack characteristic, determining whether it is genuine or counterfeit based on whether the aspect ratio, which is the ratio of the largest width value among the calculated width values ​​to the largest depth value among the calculated depth values, is within a preset threshold. Artwork authenticity determination device through crack analysis based on optical coherence tomography.

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