FIELD: information technology.
SUBSTANCE: for each image element, it is determined whether colour coordinate values in colour space associated with said image element correspond to the colour standard distribution given by at least one given bounded reference surface, defined by at least one linear section given for said type of valuable documents and given distance from points of the reference surface to said at least one linear section. Positions of the image elements, the colour coordinate values of which lie within or outside the reference surface are compared with the given reference positions on the valuable document (12) and depending on the comparison result, the presence or absence of colour transition on the analysed area caused by contamination and/or wearing of ink is determined.
EFFECT: high speed of processing valuable documents when realising the method.
16 cl, 9 dwg
