CONTOUR METHOD OF COMPRESSING GRAPHICAL FILES Russian patent published in 2008 - IPC G06T9/20 G06K9/48 H04N1/409 

FIELD: information technology.

SUBSTANCE: snap-shot of a graphic image is reduced by resising by 4 times. The snap-shot is compressed and stored as a compressed file, which can be decompressed and increased by 4 times. The initial snap-shot of the graphic image is then superimposed onto a decompressed increased snap-shot. Differences of pixel values between the initial snap-shot of the graphical image and the decompressed increased snap-shot are searched for, from a given contrast, based on contrast elements using arithmetical subtraction. After that a snap-shot with contour values is obtained, and contrast elements are compressed and stored as a compressed file.

EFFECT: increased efficiency of compressing files and reducing amount of memory required with retention of definition of the graphical image after decompression of files.

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