TITLE:        Transform coding of monochrome and color images using TCQ
AUTHORS:      K.-L. Tong and M. W. Marcellin
CONFERENCE:   Asilomar Conference on Signals, Systems, and Computers,
	      Pacific Grove, California, November 1991
ABSTRACT:
Trellis coded quantization (TCQ) is incorporated into a transform 
coding structure for encoding monochrome and color images at 1 bit/pixel. 
Both fixed-rate and entropy-constrained designs are considered. For 
monochrome images, a simple 4-state fixed-rate TCQ-based system provides 
gains in peak-signal-to-noise ratio of up to 2.4 dB over scalar quantizer 
based systems, while the entropy-constrained design provides gains of up 
to 7.0dB. Gains in PSNR for color images of up to 1.6 dB and 3.9 dB are 
achieved for the 4-state fixed-rate and entropy-constrained TCQ-based 
systems, respectively.  The subjective quality of the images produced by 
the TCQ-based systems is significantly better than that of the scalar 
quantizer-based systems. The high frequency background noise, fuzziness, 
and block artifacts produced by the scalar quantizer-based systems are
virtually eliminated by the TCQ-based systems.