CPC H04N 19/467 (2014.11) [H04N 19/124 (2014.11); H04N 19/176 (2014.11); H04N 19/18 (2014.11); H04N 19/593 (2014.11); H04N 19/625 (2014.11); H04N 19/63 (2014.11); H04N 19/91 (2014.11); G16H 30/40 (2018.01); G16H 80/00 (2018.01)] | 13 Claims |
1. A method for concealing data in an image or a video stream inside a compression chain, this method being implemented by computer and comprising the following steps:
a phase of structuring and processing during which at least one image is structured in blocks containing coefficients;
a phase of transformation and quantization of the blocks so as to generate transformed and quantized coefficients;
an entropy encoding intended to encode the transformed and quantized coefficients;
a data concealment step during which bits from the data are concealed by modifying transformed and quantized coefficients, situated in a zone of high frequencies of at least a part of said blocks which are relative to the luminance component of the video stream and which are intra-coded,
in that this modification is carried out after the quantization but before the entropy encoding;
and for a predefined concealment level k, k being comprised between 1 and N−1 for a block of size N×N, the modification applies only to the coefficients aligned below a diagonal concealment level taken across the N×N block.
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