METHOD OF COMPRESSING DIGITAL IMAGES USING FIXED NUMBER OF BITS PER BLOCK Russian patent published in 2014 - IPC G06T9/00 H04N19/103 

FIELD: information technology.

SUBSTANCE: method of compressing images programmed in a controller of a device, comprising: partitioning an image into one or more blocks; applying gamma conversion to each pixel of the image to generate data with the same number of bits; computing prediction values for each pixel in each block of the one or more blocks using a plurality of prediction modes; applying quantisation to each pixel of each block of the one or more blocks using a plurality of quantisation numbers; computing differential pulse code modulation (DPCM) to generate residuals of the quantised values for each of the plurality of quantisation numbers, wherein the number of bits generated for each block of the one or more blocks is equal to the bit budget; computing pulse code modulation (PCM), which includes shifting each pixel value by a fixed number of bits; selecting for each block of said one or more blocks, DPCM with a quantisation number where the best quantisation accuracy is achieved; selecting an encoding method from the DPCM with said quantisation number and PCM; and generating a bit stream containing data encoded using the selected encoding method.

EFFECT: compression without visual losses.

14 cl, 17 dwg