Patent ID: 7266245

Claim:
A method for compressing and decompressing image signal, said method comprising: a) a compression method for compressing a currently processing pixel X, said compression method comprising the steps of: a1) determining first N pixel value differences respectively for N pairs of pixels belonging to first K neighboring pixels of said pixel X that have respectively first K currently buffered pixel values, wherein each of said first N pixel value differences is associated with one of said first K neighboring pixels; a2) predicting a pixel Q to have similar pixel value with said pixel X by choosing said pixel Q from said K neighboring pixels, said pixel Q associated with one of said first pixel value differences that has the greatest value among said first N absolute pixel value differences; and a3) compressing P(X) into a compressed data delta(X) to be transmitted for decompression, said delta(X)=P(X)−enKey(X), wherein said enKey(X) denotes an encryption key for compressing P(X) into said delta(X), said enKey(X) having value of P(Q), the pixel value of pixel Q.