Patent ID: 6229930
Filing Date: 2001-05-08
Classification: G06K,H04N

Abstract:
An image processing apparatus for coding a transparency signal corresponding to an object constituting an image, said transparency signal indicating a composition ratio used when compositing an image signal corresponding to the object with another image signal, said apparatus comprising:scaling value detection means for receiving a transparency signal which has been subjected to a process of changing its signal value with a fixed scale factor, and detecting a specific signal value corresponding to the fixed scale factor, as a scaling value;scaling means for performing scaling on the transparency signal whose signal value has been changed, by using the detected scaling value, and outputting a scaled transparency signal whose signal value is restored to the signal value before the change;first coding means for coding the scaling value to output coded scaling value data;blocking means for dividing the scaled transparency signal into signals corresponding to a plurality of blocks each comprising a predetermined number of pixels, and outputting a transparency signal corresponding to each block; andsecond coding means for coding the transparency signal corresponding to each block to output a coded transparency signal;wherein the coded scaling value data and the coded transparency signal corresponding to each block are output as coded data of the transparency signal.