Browsing International Telemetering Conference Proceedings, Volume 44 (2008) by Authors
Joint JPEG2000/LDPC Code System Design for Image TelemetryRyan, William E.; Marcellin, Michael W.; Bilgin, Ali; Jagiello, Kristin; Aydin, Mahmut Zafer; Ng, Wei-Ren; University of Arizona (International Foundation for Telemetering, 2008-10)This paper considers the joint selection of the source code rate and channel code rate in an image telemetry system. Specifically considered is the JPEG2000 image coder and an LDPC code family. The goal is to determine the optimum apportioning of bits between the source and channel codes for a given channel signal-to-noise ratio and total bit rate, R(total). Optimality is in the sense of maximum peak image SNR and the tradeoff is between the JPEG2000 bit rate R(source) and the LDPC code rate R(channel). For comparison, results are included for the industry standard rate-1/2, memory-6 convolutional code.
Scalable Perceptual Image Coding for Remote Sensing SystemsMarcellin, Michael W.; Bilgin, Ali; Oh, Han; Lalgudi, Hariharan G.; University of Arizona (International Foundation for Telemetering, 2008-10)In this work, a scalable perceptual JPEG2000 encoder that exploits properties of the human visual system (HVS) is presented. The algorithm modifies the final three stages of a conventional JPEG2000 encoder. In the first stage, the quantization step size for each subband is chosen to be the inverse of the contrast sensitivity function (CSF). In bit-plane coding, two masking effects are considered during distortion calculation. In the final bitstream formation step, quality layers are formed corresponding to desired perceptual distortion thresholds. This modified encoder exhibits superior visual performance for remote sensing images compared to conventional JPEG2000 encoders. Additionally, it is completely JPEG2000 Part-1 compliant, and therefore can be decoded by any JPEG2000 decoder.