METHOD OF DETERMINING COPY OF DOCUMENT FROM COLOUR IMAGE OF DOCUMENT Russian patent published in 2025 - IPC G07D7/12 G06V10/20 

FIELD: computer equipment.

SUBSTANCE: method includes: obtaining, using a camera under uncontrolled image capturing conditions, in an RGB model, projective correction, colour normalization and separation and analysis of achromatic pixels; wherein the background of the document is analysed and determining, based on the colour characteristics, whether the background is paper; at that, at the projective correction stage, a transformation is applied, which is designed to compensate for the projective distortions of the document; on the analysis of achromatic pixels, four background regions around the document are considered, for each part a decision is made whether it is achromatic, if at least two background regions are recognized as achromatic, it is considered that the printed copy of the document was captured, and not the original document.

EFFECT: providing a method of determining a copy of a document from a colour image and ensuring stability of operation under different illumination, colour calibration errors of the image capturing device, when presenting copies obtained using different modes, as well as ensuring independence from the type of document and stability of operation with different resolutions.

1 cl, 5 dwg