METHOD AND DEVICE FOR COLOUR IMAGE DECODING Russian patent published in 2020 - IPC H04N19/186 H04N19/30 H04N19/98 H04N19/44 

FIELD: physics.

SUBSTANCE: invention relates to the computer equipment. Method of decoding a colour image from a bitstream, in which an additional luminance component is obtained by linear combination of luminance and chrominance components obtained from the bitstream; obtaining a first component by applying a nonlinear dynamic expansion function to an additional luminance component such that the dynamics of the first component increases compared to the dynamics of the additional luminance component; obtaining the normalized multiplication factor from the multiplication factor obtained from the bit stream and the first component; restoring the colour component of the colour image to be decoded from the chroma components and the first component by steps on which: obtaining chromaticity intermediate components from chroma components and a normalized multiplication factor; obtaining an intermediate colour component of two intermediate chromaticity components, a product of two intermediate chromaticity components and a colour conversion matrix; and obtaining a colour component of the decoded colour image from the first component and the intermediate colour component.

EFFECT: technical result consists in improvement of reliability of colour image decoding.

14 cl, 6 dwg