FIELD: engineering of circuit for compressing image signals, using blocks and sub-blocks of adaptively determined sizes of given coefficients of discontinuous cosine transformation.
SUBSTANCE: block size-setting element in encoder selects a block or sub-block of processed input pixels block. Selection is based on dispersion of pixel values. Blocks with dispersions greater than threshold are divided, while blocks with dispersions lesser then threshold are not divided. Transformer element transforms pixel values of selected blocks to frequency range. Values in frequency range may then be quantized, transformed to serial form and encoded with alternating length during preparation for transmission.
EFFECT: improved computing efficiency of image signals compression stages without loss of video signals quality levels.
4 cl, 5 dwg
