RU2752791C1 - Method for determining presence of interventions and modifications in image of text electronic document - Google Patents

Abstract

FIELD: computing technology.SUBSTANCE: method for determining the presence of interventions and modifications in an image of a text electronic document includes displaying the text electronic document on the screen of a first monitor, illuminated in a predetermined sequence with a change in the illumination angle using light emitters through light filters, ultraviolet emitters, white light emitters and infrared emitters, fixing the image of the document on the first monitor by means of a digital video microscope, obtaining digital duplicates (DDs) of the document in separate areas of the spectrum and in the area of spectral imposition, fixing the obtained images and creating colour analogues of the digital duplicates (CADDs) independent of the DDs in different light scales of the rays, wherein the fragments of the DDs and CADDs of the document obtained using the digital video microscope are alternately projected on the second monitor and the presence or absence of interventions and modifications in the text document is determined by the identified differences between the fragments of images of the obtained DDs and CADDs.EFFECT: providing a possibility of identifying interventions and modifications by analysing images of text electronic documents.2 cl, 3 dwg

Description

The invention relates to the field of image analysis of text electronic documents of any format in order to identify interventions and make changes (fakes) in text information to determine the authenticity of electronic documents and can be used in the field of forensic science for the purposes of forensic examination of documents, as well as in the field of archeology, biology, medicine, art.

From the prior art, numerous technical solutions are known associated with the analysis of certain documents and, in particular, with the determination of their authenticity using various optical means and radiation, for example:

- RU 2234734, which relates to the field of optical recognition of text from a raster image and includes the following steps - segmenting the image into regions, text fragments, character images, character recognition and corresponding analysis;

- RU 2452030, which relates to the detection of counterfeit value documents and is based on the determination of the intensity of an optical measuring signal in the visible or invisible spectral region at several analyzed points on the value document, for example, using a luminescence signal excited by ultraviolet radiation;

- US2015279143A1, which is based on the exposure of the document area to different wavelengths of the first and second electromagnetic radiation waves and obtaining, by the image sensor, the first and second images of the document area corresponding to the first and second radiation wavelengths, which makes it possible by making comparisons of the radiation intensity values to determine whether the document is genuine;

- RU 2229744 (prototype), which consists in the fact that the examined document is illuminated with a light source, the reflected luminous flux is converted into a video signal, reproduced on the monitor and the received video signal is analyzed by comparison with the undistorted image of the document, the isolated defect is classified and, in accordance with the classification, the configuration of illuminators and filters by controlling light sources with different spectral characteristics and choosing a set of filters optimal for the detected defect, the analyzed document is processed with the specified configuration of illuminators and filters simultaneously or sequentially, and the resulting image is converted into a video signal and re-visualized on the monitor, archiving the resulting image.

The disadvantage of the listed known technical solutions is their inability to fully and efficiently analyze images of electronic documents of any formats in order to determine interventions and changes in the text information of documents presented in electronic form in any formats for their storage and reproduction (PDF, DOC, TIFF, TIF, JPEG, PNG, PSD, MPEG-1, etc.). In addition, the study of documents in known technical solutions, as a rule, is limited either by the format of the studied image (for example, a raster image), or by an object (for example, only valuable documents in paper form or banknotes), or by the technical means used, with a limited set of which complete cleaning of the analyzed document image from electromagnetic interference is not provided.

The technical problem to be solved by the invention is to obtain the ability to reliably identify interventions and modifications from the image of text documents presented in electronic form without restrictions on the type of documents.

The technical result provided by the claimed invention is to expand the functionality of the method due to the possibility of detecting interventions and modifications (forgeries) by analyzing images of text electronic documents and increasing the reliability of detecting forgeries.

The achievement of the specified technical result is provided by the proposed method for determining the presence of interventions and modifications in the image of a text electronic document, which includes the use of a multifunctional video microscopic spectral complex containing a first monitor, a digital video microscope with a second monitor, at least one ultraviolet emitter, at least one emitter of white light and at least one infrared emitter associated with control devices, light emitters with a gamut of different colors, light filters of said emitters and a device for processing signals from a digital video microscope, displaying a text electronic document to be analyzed on the screen of the first monitor, which, in a predetermined sequence with changing the angle of illumination alternately and / or simultaneously illuminate with the said light emitters through appropriate light filters, ultraviolet emitters, emit firs of white light and infrared emitters, the implementation of the fixation by means of a digital video microscope the document image illuminated in this way on the first monitor with obtaining digital twins (CD) of the document in separate spectral zones and in the spectral overlay zone, and the created CDs are alternately displayed on the screen of the first monitor and illuminated by the corresponding emitters, record the obtained images by means of a digital video microscope and create color analogs of digital twins (DTSD) independent of the DSC in different light gamuts of beams, alternately project the fragments of the DSC and DSC of the document obtained using the digital video microscope onto the second monitor and determine the presence or absence of interference and modifications in the text document according to the revealed differences from each other of the image fragments obtained by the CD and the CAD.

In addition, the digital filtering of the image obtained by the CD and the CDA is additionally carried out from the radiation emanating from the screen of the first monitor on which the document is displayed, from individual image pixels and from ambient natural and artificial lighting.

The invention is illustrated by drawings, which show:

in fig. 1 - used for the analysis of electronic documents and images "Forensic multifunctional video microscopic spectral complex" (hereinafter - Spectral complex),

in fig. 2 is a general scheme for analyzing a document or image using the Spectral Complex,

in fig. 3 is an example of the obtained digital twin of a fragment of the object of research (document) with an indication of the interventions (forgeries) made.

The method can be implemented using known multifunctional video microscopic spectral complexes used in forensic science to study the authenticity of documents containing the first monitor 2 (Fig. 2), digital video microscope 1 with a second monitor 11 (Fig. 1), at least one ultraviolet emitter 8 , at least one emitter of white light 9 and at least one infrared emitter 7 associated with control devices 13, light emitters with a gamut of different colors 10, light filters of said emitters 12 and a device for processing signals from a digital video microscope (not shown in Fig. ), for example, the spectral complex described in RU 2678413.

The screen of the first monitor of the spectral complex displays a document presented in electronic form in any of the existing storage and playback formats (PDF, DOC, TIFF, TIF, JPEG, PNG, PSD, MPEG-1, etc.), while the image is text information can be monochrome (Gray), binary or color (RGB). The document image on the first monitor in a predetermined sequence with a change in the angle of illumination is alternately and / or simultaneously illuminated using light emitters through appropriate light filters of ultraviolet emitters, white light emitters and infrared emitters of the spectral complex. The sequence of illumination is set depending on the complexity of the object of study, while the image on the monitor can be illuminated both by oblique beams and by direct beams. Thus, the object of analysis is exposed to radiation 3 (Fig. 2) in the infrared, ultraviolet and visible ranges with the simultaneous use of various light filters, as well as with the superposition of the reflected radiation of different zones (ranges) of the spectrum on top of each other. Then, using a digital video microscope, observation is carried out on the first monitor of the object of study (document image), highlighted in this way, as well as its fixation and processing of the results data using a signal processing device, in the process of which a set of digital images of the document image in different spectral ranges is obtained, which are digital twins (CD) of the document under study.

The created CDs are alternately displayed on the screen of the first monitor and illuminated by means of appropriate emitters, while the obtained images are recorded by means of a digital video microscope and color analogs of digital twins (CDTs) independent of the CD are created in various light gamuts of rays. In general, for the analysis, from 5 to 25 images of CD and CDC can be created, which, in order to clean the image from electromagnetic "noise" in the signal processing device, can be additionally subjected to digital filtering, including from radiation emanating from the screen of the first monitor, on which displays the document, from individual pixels of the image and from the ambient natural and artificial lighting, which makes it possible to increase the reliability of detecting forgeries - see, for example, Allaberganov A.A., Kataev M.Yu. "The content and type of the unified expert opinion", the journal "Gaps in Russian legislation", No. 1, 2020, p. 228, fig. 10.

Fragments of the CD and TsAD of the document, obtained using a digital video microscope, are alternately projected onto the screen of a second monitor connected to the video microscope. From a comparative analysis of fragments of images of the CD and CDC, it is possible to obtain with high accuracy information about the presence or absence of interventions and modifications in a text document based on differences, for example, in the brightness of text elements in different spectral zones of illumination, from the original text.

In the absence of interventions and modifications in the text document, when viewing the obtained images in different spectral zones of illumination, differences in the elements of the text will not appear, which in this case is only the original text without changes.

An example of the interference detected during the analysis of document images in different spectral regions of the backlight is shown in FIG. 3, where:

4 - strokes of letter elements on the lower layer of text information, i.e. the original text, which, when appropriately highlighted, appears as highlighted areas.

5 - strokes of lettering elements on the upper layer of the text, i.e. this is the second layer of text, applied on top of the original text and which, with appropriate illumination, looks like black areas - image editing,

6 - remnants of the text editor pixels during image editing, visible as black dot areas, i.e. these are traces of work to forge the text.

The difference between strokes 4 on the bottom layer is that they are not visible without the above manipulations with the text and have specific outlines (lines of letters, numbers, etc.). Strokes 5 on the top text layer reflect the main (not hidden) text of the document, which is visible to the naked eye. The remnants of 6 pixels do not have specific outlines - they are "dirt" around the letters.

Thus, when viewing the resulting set of images of the text of the document in different spectral zones of illumination when the outlines of another text are displayed in the analyzed text (strokes 4 on the lower layer), i.e. when detecting differences from each other fragments of images obtained by the CD and TSAD, it is concluded that there are interventions and modifications in the text document.

The described analysis of text electronic documents in order to identify interference and modifications (forgeries) in text information allows us to determine with a high degree of reliability the authenticity of the submitted documents.

Claims (2)

1. A method for determining the presence of interventions and modifications in the image of a text electronic document, comprising the use of a multifunctional video microscopic spectral complex containing a first monitor, a digital video microscope with a second monitor, at least one ultraviolet emitter, at least one emitter of white light and at least one infrared emitter associated with control devices, light emitters with a gamut of different colors, light filters of the aforementioned emitters and a device for processing signals from a digital video microscope, displaying a text electronic document to be analyzed on the screen of the first monitor, which in a predetermined sequence with a change in the angle of illumination alternately and / or simultaneously illuminated with said light emitters through appropriate light filters, UV emitters, white light emitters and infrared emitters, fixing by means of m of the digital video microscope of the document image illuminated in this way on the first monitor with the receipt of digital twins (CD) of the document in separate spectral zones and in the spectral overlay zone, and the created CDs are alternately displayed on the screen of the first monitor and illuminated by means of appropriate emitters, the resulting images are recorded by means of a digital video microscope and create color analogs of digital twins, independent of the CD, in various light gamuts of rays, while alternately projecting fragments of the CD and the CD of the document obtained using a digital video microscope onto a second monitor and determining the presence or absence of interventions and modifications in the text document according to the identified differences from each other of the image fragments obtained by the CD and TsAD. 2. The method according to claim 1, characterized in that it additionally carries out digital filtering of the image of the obtained CD and CDC from radiation emanating from the screen of the first monitor on which the document is displayed, from individual image pixels and from ambient natural and artificial lighting.

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