RU2819345C1 - Method of identifying paintings for their authenticity - Google Patents

Abstract

FIELD: identification of cultural objects.

SUBSTANCE: essence of the invention consists in the fact that the painting works identification method for their authenticity comprises the following stages, on which before performing the identification of the analyzed painting, the magnetic field induction is measured at a minimum distance from the plane of its characteristic dimensions and a graphical image ("magnetic" passport) of the distribution of the measured values of the magnetic field induction by the coordinate points of the measurement plane is drawn up, which is superimposed on the image of the painting, reproduced on the computer monitor, after which the quantitative value of the indicator of reliability of identifying the painting is determined.

EFFECT: high accuracy of identifying authenticity of painting.

1 cl

Description

The invention relates to methods for identifying cultural objects, in particular for identifying works of art in order to protect them from counterfeiting.

The procedure for identifying works of art (paintings) involves performing appropriate studies of the painting and comparing the results with the original.

There are various ways to identify paintings from fakes. The choice of one or another identification method should be determined by its reliability, which is assessed both by quantitative indicators and by the legal significance of the procedure for obtaining the result of its application. At the same time, the legal significance of the identification procedure is understood not so much as the legal execution of the relevant act (or protocol), but rather the performance of research operations in accordance with the requirements legally established by federal legislation.

There is a known method (US 5521984 A dated May 28, 1996) for determining the authenticity of works of art through the use of unique inherent features. The method includes placing the image object under study in equipment that provides recording of a microscopic image, selecting a micro-area on the object under study, recording an enlarged microscopic image of unique features on the selected one, and storing the data in a central storage. Subsequently, if necessary, the data is retrieved from their storage and the corresponding images of micro-sections of the stored and studied image object are compared.

In addition, there is also a known method for identifying works of art (US 6017218 A dated January 25, 2000), which consists of comparing strokes or brush marks of the work under study with strokes of one or more known works of art.

There is a method for identifying religious objects (RU 2205451 C1 dated May 27, 2003), in which the resulting image of at least one section of the identified object is compared with the registered image of the section, and when selecting each section of the surface, the coordinates of the point are set according to a random law, relative to which determines the shape and size of this surface area.

There is also a known method (RU 2333613 C1 dated 02.08.2007), in which identification is performed by obtaining an image of the original work of painting through color digital photography and displaying the image data on a computer monitor, after which, using computer cropping, the data of fragments of the painting are isolated and examined from different color spots that make up the palette of the work. The advantage of this method is the ability to record and analyze identification information for the authenticity of a work of art, however, studying a painting using fragments of color spots has the disadvantage of changing color over time.

The common disadvantages of all the methods described above are their significant labor intensity, requiring art history qualifications and experience, as well as the lack of a legally significant quantitative determination of the reliability of the identification result.

The closest in essence to the claimed invention is the method RU 2333613 C1 dated 08/02/2007, which is accepted as the prototype method.

The task to which the claimed invention is aimed is to identify works of art by characteristics that reflect their material essence and do not change over time, excluding the common shortcomings inherent in existing identification methods.

The essence of the claimed invention is as follows.

Many art paints have pigments based on ferrous oxide compounds (for example, Fe ₂ O ₃ or Fe ₂ C ₃ ) or salts (for example, Fe ₄ [Fe(CN) ₆ ] ₃ or Fe ₃ (PO ₄ ) ₂ ). When applied to canvas, these paints become sources of a static magnetic field (MF), so one of these identification characteristics that does not change over time may be the induction of such a MF.

The technical result obtained by implementing the claimed invention consists in drawing up a graphical representation of the distribution of the measured values of the MF induction of a work of art along the coordinate points of the measurement plane, performed at a minimum distance from the plane of its characteristic dimensions, with an assessment of the accuracy of the resulting “magnetic” image.

The specified technical result in the claimed method of identifying works of art for their authenticity is achieved by the fact that, in contrast to the prototype method, before identifying the work of art under study, a “magnetic” passport is formed by measuring the induction of its magnetic field at a minimum distance from the plane of its characteristic dimensions and make a graphical representation of the distribution of the measured values of the magnetic field induction along the coordinate points of the measurement plane, which is superimposed on the image of the painting reproduced on the computer monitor screen, compare the characteristics of the work under study with the previously issued “magnetic” passport of the original painting, by determining the quantitative value of the indicator reliability of identification of a work of painting.

The process of identifying works of art (objects) for their authenticity using the proposed method has three stages (preparatory, measuring and identification) and is carried out as follows.

1. At the preparatory stage, preparation for measurements is carried out, which consists of installing the object of study in a measuring-coordinate system in a special room, protected from external MFs and forming its natural MF with a damped external MF.

2. At the measuring stage, measurements of the magnetic field induction of the object are carried out at a minimum distance from the plane of its characteristic dimensions, and a graphic image of the distribution of the measured values of the MF induction along the coordinate points of the measurement plane is compiled, which is superimposed on the image of the painting reproduced on the computer monitor screen.

The compiled graphic image of the distribution of the measured values of MF induction along the coordinate points of the measurement plane, superimposed on the image of the work of painting, reproduced on the computer monitor screen, is issued as its “magnetic” passport.

The measuring stage is the main stage of the initial examination of a work of art, necessary for issuing its magnetic passport to perform further procedures for identifying the work of art during an expert assessment of the authenticity of the work of art.

Assessing the accuracy of the measurement information of the “magnetic” passport of a work of art is its main legal feature, since the measurement procedure is subject to the requirements of Federal Law No. 102-FZ “On Ensuring the Uniformity of Measurements.” The quantitative indicator of the accuracy of the measuring information of the “magnetic” passport is determined by the accuracy (metrological) characteristics of the measurement procedure used.

A “magnetic” passport of a work of art can be stored on secure digital media in special archives.

3. At the identification stage, a comparison is made of the characteristics of the work of art under study with the previously issued “magnetic” passport of the original painting. The comparison procedure in this case is an analogue of the comparison method borrowed from metrological practice, defined by the recommendations for interstate standardization RMG 29-2013 (GSI. Metrology. Terms and definitions). In this case, the original picture, in relation to which the comparison (identification) procedure of the picture under study is carried out, is taken as a “standard” (measure of comparison).

The assessment of identification reliability in this case includes both a quantitative indicator of the accuracy (error) of the measuring information of the “magnetic” passport of a work of art, and a quantitative indicator of the accuracy (error) of comparing the object under study with the “magnetic” passport of the painting taken as the original.

The reliability indicator (error) of identification D _ID in this case can be defined as the reciprocal value of the error δ _ID , i.e.:

D _ID =1-δ _ID , %

In this case, the value of δ _ID is determined as the square root of the sum of the component errors:

,

where δ _MP is a quantitative indicator of the accuracy of the measuring information of the “magnetic” passport of a work of art (measurement error). The measurement error δ _MF is determined by the measurement technique, which is subject to metrological certification and inclusion in the State Register of Measurement Techniques.

δ _CPs is a quantitative indicator of the accuracy of comparison of the studied painting with the “magnetic” passport of the original painting according to the measurement discreteness characteristic (comparison error “by area”), defined as

,

where S _D is the size of the measuring area (measuring size) of the sensor in the measurement plane perpendicular to its magnetically sensitive axis;

S _K - the total measuring area (measuring size) of the painting taken as the original.

δ _CPв is a quantitative indicator of the accuracy of comparison of the studied painting with the “magnetic” passport of the original painting based on the values of the measurement results (comparison error “by values”), defined as

,

where N _B is the number of measured values of the MF induction of the picture under study, which coincided (taking into account δ _MF ) with the corresponding (at measurement points) values of the “magnetic” passport of the original picture;

N _Σ - the total number of measurement points of the “magnetic” passport of the original painting.

For illustration, a model of the procedure for identifying the compared painting Y with the “magnetic” passport of painting X, taken as the original, is considered.

The following particular characteristics were taken as initial data for assessing the identification reliability indicator ( _DID ):

δ _MP =1.5%; S _D =10 ^{-4 m2} ; S _K =1.0 m ² ; N _B =980; N _Σ =1000.

In this case, the identification error δ _ID is defined as:

And, accordingly, the reliability of identification is defined as:

D _ID =1-δ _ID =1-2.25=97.75 (%).

Thus, in the considered model of the identification problem, the identification reliability indicator D _ID is determined to be 97.75% with an identification error δ _ID = 2.25%.

Additional advantages of the claimed invention are:

- study of the entire area of the picture with discreteness of the measuring sensor size;

- efficiency (preparing and conducting the study takes no more than 8 hours);

- there are no requirements for the operator’s art history qualifications;

- determination of the quantitative value of the identification reliability indicator based on the implementation of objective procedures.

A “magnetic” passport of a work of art, issued based on the results of the study, can be the main legally significant expert document when assessing its authenticity.

The implementation of the claimed invention provides the expert community with an additional instrumental and methodological apparatus that will make it possible to establish the authenticity of works of art as objectively and with a certain reliability as possible and thus protect them from forgeries, as well as to explore the correlations of the characteristics of works of art and the identification of their author's invariants.

With appropriate changes in the instrumental and methodological apparatus of the study, the essence of the invention can also be used to identify for authenticity any works of art (sculptures, decorative forms, etc.), the material of which contains ferrous and other magnetic compounds.

Claims (3)

A method for identifying works of art for their authenticity, which consists in obtaining an image using color digital photography, characterized in that Before identifying the work of art under study, a “magnetic” passport is formed by measuring the induction of its magnetic field at a minimum distance from the plane of its characteristic dimensions and a graphical representation of the distribution of the measured values of the magnetic field induction along the coordinate points of the measurement plane is drawn up, which is superimposed on the image of the work of art reproduced on computer monitor screen, compare the characteristics of the work under study with the previously issued “magnetic” passport of the original painting by determining the quantitative value of the indicator of reliability of identification of the work of art.