Patent ID: 6295375
Filing Date: 2001-09-25
Classification: H04N

Abstract:
A method of coding a sequence of pictures comprising at least the steps of:subdividing each input picture into sub-pictures;quantizing said signals with a variable quantizing scale;encoding said quantized signals;wherein said method also comprises, before said quantizing step, the additional sub-steps of:generating from each input picture a set of visual sensitivity values S(i) respectively associated to sub-pictures i of said input picture;computing from said set of values perceptual coefficients W(i), one per sub-picture, said computation being based on the cumulative distribution function F(S(i)) associated to said values S(i) and according to the following expression:W(i)=(1+a/2)-(a.F(S(i)))where a is a constant provided for controlling the modulation amplitude.