Patent ID: 6154571
Filing Date: 2000-11-28
Classification: G06T,H04N

Abstract:
A method of inserting a watermark signal into video images comprising the steps of:receiving input video images;performing discrete cosine transformation (DCT) of said input video images to obtain DCT values of said input video images;adding watermark signals to said DCT values to obtain DCT values with watermark;performing an inverse DCT on the DCT values with watermark for generating watermarked images;subtracting predicted images from said watermarked images for generating residual images;obtaining the DCT values of residual images and quantizing the DCT values of the residual images;inverse quantizing the quantized DCT values of the residual images;performing discrete cosine transformation of the predicted images;summing the inverse quantized DCT values of the residual images and the DCT of the predicted images for generating DCT coefficients for decoded images;calculating correction signals from the DCT coefficients of the decoded images and adding the correction signals to the quantized DCT values of the residual images for obtaining an output signal;inverse quantizing the output signal, inverse DCT the inverse quantized output signal and summing the resultant signal with the predicted images for generating a summed signal;storing the summed signal in memory for generating the predicted images; andvariable length encoding the output signal for providing a watermarked MPEG video signal of the input video images.