Content-based compression and transmission of astronomical Images

The next generation space telescope (NGST) is expected to produce a vast amount of raw images, which need to be stored and disseminated efficiently for astronomical research and education. Therefore, effective compression and transmission methods are very important. This paper proposes a joint compression and transmission scheme for efficient streaming of astronomical images based on their special characteristics. The objective of the joint approach is to maximize the recognition of the astronomical entities presented in the image under the same rate constraint and channel loss behavior. In the compression stage, each astronomical entities is segmented and coded independently using zero-tree based wavelet codec, and robust packetization scheme is employed to prevent error propagation; in the transmission stage, content information of the image is utilized to maximize the perceptual quality of the entities at the presence of packet loss. Experiment results are presented to demonstrate the effectiveness of the proposed approach.