Patent ID: 6775412
Filing Date: 2004-08-10
Classification: H04N

Abstract:
A method of lossless region of interest transmission of an S+P transform coded digitized image, comprising:calculating a mask indicating the coefficients of the S+P transformed image, which corresponds to the region of interest, and that these coefficients are transmitted, wherein the mask is obtained by tracing a step backwards on a separate line, and the following steps then are carried out: set Hm(n)=1 If {Xm(2n)=1} OR {Xm(2n+1)=1}, and 0 otherwise set Lm(n)=1 If {Xm(2nâˆ’2)=1} OR {Xm(2nâˆ’1)=1} OR {Xm(2n)=1} OR {Xm(2n+1)=1} OR {Xm(2n+2)=1} OR {Xm(2n+3)=1}, and 0 otherwise for all n in [1 . . . N/2], where Xm(n) is the mask before the step inversion, Lm(n) and Hm(n) are the masks for the low and high frequency sub-band afterwards, respectively, and where n is the number of a coefficient in line, which is updated.