METHOD OF DETERMINING SIGNS OF INSTALLATION ON COPIES OF DOCUMENTS MADE WITH ELECTROPHOTOGRAPHIC METHOD Russian patent published in 2016 - IPC G01J3/46 G07D7/00 

FIELD: examination.

SUBSTANCE: invention relates to technical expert evaluation of documents and can be used in forensic expert, forensic and forensic practice at investigations in order to detect forgery signs on copies of documents made by electrophotographic method. Method consists in fact that digitisation of document is performed by scanning text fragments on document sheet, preliminary processing of digital copy of document is performed by removing sections not containing printed text. Number of pixels is calculated, containing various colour of text, each of which is characterised by corresponding values of colour model, text colours most frequently occurring in document are determined. Values of colour model for these colours for various fragments of text document are averaged, obtained values for various fragments of document text are compared, and when detecting differences in averaged values of colour model and in colour model of most frequent colour at various fragments of text, conclusion on presence of forging on this document sheet. As colours of text often use different tones of grey colour. As colour model preferably used is RGB colour model.

EFFECT: invention increases reliability of detecting signs of forgery on copies of documents made by electrophotographic method due to use of objectively measured parameters characterising text on various fragments of document page.

3 cl, 1 tbl