Patent ID: 7729505
Filing Date: 2010-06-01
Classification: G06T

Abstract:
1. A method of inserting a watermark composed of a plurality of binary information in an image comprising at least three components, the method comprising of: decomposing at least one component of the image into detail sub-bands in various directions and comprising coefficients, each coefficient being characterized by its position in the detail sub-band to which it belongs and its amplitude; determining, for each position, information representing local amplitude variations in various directions from amplitudes of the coefficients at the position in the various detail sub-bands and coefficients close to the position in the various detail sub-bands; determining, a watermarking strength at each position from information representing local amplitude variations in various directions determined for the position; forming, for each position and for each decomposed component, a vector whose coordinates are the amplitudes of the coefficients at the position in the various detail sub-bands of the component; selecting, for each position, one vector amongst the vectors formed for the position; watermarking the image by modifying, for each position, the amplitude of the coefficients which are the coordinates of the vector selected for the position according to the binary information corresponding to the position and according to the watermarking strength determined for the position.