Title :
Edge-preserving ADPCM and ECVQ coding of image sub-bands using subjective criteria
Author :
Jourdan, Marcelo Mollica ; Alcaim, Abraham
Author_Institution :
Centro dfe Estudos em Telecomunicacoes, Pontificia Univ. Catolica do Rio de Janeiro, Brazil
Abstract :
We propose an adaptive sub-band image coder designed according to subjective criteria. A pre-processing technique is applied to the high subbands and discards local information irrelevant to the overall subjective quality. Pixels not removed by this technique are classified as edges and non-edges by means of a specific algorithm designed for each sub-band. The two classes in each high-frequency sub-band are quantized with entropy constrained vector quantizers (ECVQ). The low sub-band is encoded with an edge-preserving ADPCM. Both in terms of PSNR and visual quality the proposed codec offers meaningful improvements compared to the JPEG algorithm
Keywords :
adaptive signal processing; differential pulse code modulation; edge detection; entropy codes; image classification; image coding; vector quantisation; ECVQ coding; JPEG algorithm; PSNR; adaptive subband image coder; edge preserving ADPCM coding; edges; entropy constrained vector quantizers; high frequency subband; high subbands; image subbands; nonedges; pixels classification; preprocessing technique; subjective criteria; subjective quality; visual quality; Algorithm design and analysis; Bit rate; Codecs; Entropy; Image coding; PSNR; Quantization; Redundancy; Telecommunications; Transform coding;
Conference_Titel :
Image Processing, 1996. Proceedings., International Conference on
Conference_Location :
Lausanne
Print_ISBN :
0-7803-3259-8
DOI :
10.1109/ICIP.1996.560518
