METHOD FOR CHECKING COLOUR OF DOCUMENT BASED ON ITS IMAGE OBTAINED UNDER UNCONTROLLED SHOOTING CONDITIONS Russian patent published in 2023 - IPC G06T7/90 

FIELD: authenticity verification.

SUBSTANCE: invention relates to the verifying the authenticity of images of documents of various types, namely to the checking whether the displayed document is an image of an original colour document or a black and white copy thereof received by a mobile device in an uncontrolled environment. A method for monitoring the colour of a document from its image obtained under uncontrolled shooting conditions involves comparing the colour histograms of the input colour photograph of the document and the document template, wherein the image of the document is a square image, the upper left vertex of which is located at the origin of the image coordinates, and the sides of the document are parallel sides of the image, wherein the template specifies a set of document elements that are unchanged for different instances of documents of a given type and are anisotropically scaled to the size of the input image of the document, and the method contains the stage of pre-processing the input image, including increasing contrast, filtering “black” pixels, colour normalization, transition to chromaticity coordinates, the stage of constructing and pre-processing chromaticity histograms, including constructing a chromaticity histogram and specifying regions, processing chromaticity histograms, the stage of comparing histograms of images of the input document and template and making a decision about the chromaticity of the document.

EFFECT: increased accuracy of document verification.

1 cl, 5 dwg