Showing papers by "Russell M. Mersereau published in 1997"

Lossless compression of computer generated animation frames

Abstract: This article presents a new lossless compression algorithm for computer animation image sequences. The algorithm uses transformation information available in the animation script and floating point depth and object number information at each pixel to perform highly accurate motion prediction with vary low computation. The geometric data (i.e., the depth and object number) can either be computed during the original rendering process and stored with the image or computed on the fly during compression and decompression. In the former case the stored geometric data are very efficientlycomporessed using motion prediction and a new technique called direction coding, typically to 1 to 2 bits per pixel. The geometric data are also useful in z-buffer image compsiting and this new compression algorthm offers a very low storage overhead method for saving the information needed for this comoositing. The overall compression ratio of the new algorithm, including the geometic data overhead, in compared to conventional spatial linear prediction compression and block-matching motion. The algorithm improves on a previous motion prediction algorithm by incorporating block predictor switching and color ratio predition. The combination of thes techniques gives compression ratios 30% better than those reported previously.

MPEG-2/ECVQ look-ahead hybrid quantization and spatially scalable coding

Abstract: In this paper, a nonlinear approach to spatially scalable coding is developed. Within the context of the MPEG-2 scalable syntax, various decimation and prediction schemes are discussed for the interlaced and progressive format video processing. A novel spatio-temporal video interpolation technique is presented, which is used as the basic unit in the prediction schemes. In addition to the considerable scalability techniques, a lookahead quantization scheme is introduced for P- and B-type picture coding. The new quantization scheme results in further performance improvement by selective combination of the DCT domain scalar quantization and the spatial domain entropy- constrained vector quantization. The performance of the proposed scalable scheme is compared with that of the simulcast technique and the single layer coding. Remarkable performance improvement over the simulcast coding is achieved. While spatial scalability involves multi-layer coding, the new scalable scheme also achieves comparable or better performance that the single layer coding.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

MPEG-2/ECVQ lookahead hybrid quantization and spatially scalable coding

Abstract: In this paper, a nonlinear approach to spatially scalable coding is developed. Within the context of the MPEG-2 scalable syntax, various decimation and prediction schemes are discussed for the interlaced and progressive format video processing. A novel spatio-temporal video interpolation technique is presented, which is used as the basic unit in the prediction schemes. In addition to the considered scalability techniques, a lookahead quantization scheme is introduced for P- and B-type picture coding. The new quantization scheme results in further performance improvement by selective combination of the DCT domain scalar quantization and the spatial domain entropy-constrained vector quantization. The performance of the proposed scalable scheme is compared with that of the simulcast technique and the single layer coding. Remarkable performance improvement over the simulcast coding is achieved. While spatial scalability involves multi-layer coding, the new scalable scheme also achieves comparable or better performance than the single layer coding.