METHOD, DEVICE FOR ENCODING, TRANSMITTING AND DECODING IMAGE SIGNAL AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To perform effective image edition to a composite image by performing scalable encoding to 1st and 2nd image signals and a key signal for synthesizing these image signals. SOLUTION: A background image, foreground image and key signal are respectively separately encoded and respective bit streams are multiplexed so that a bit stream corresponding to these three signals can be constituted. An image signal encoding part 61 encodes the high-order and low-order layer image signals of the foreground image. Based on a motion vector and a predictive mode from the image signal encoding part 61, a key signal encoding part 62 encodes high-order and low-order layer key signals through scalable encoding. The bit stream of encoded high-order and low-order layer image signals and the bit stream of encoded high-order and low-order layer key signals are multiplexed by a multiplexing part 63 and outputted through a transmission buffer 64 as one encoded bit stream.