Title :
Convex projections based edge recovery in low bit rate VQ
Author :
Narayan, Ajai ; Doherty, John F.
Author_Institution :
Dept. of Electr. Eng. & Comput. Eng., Iowa State Univ., Ames, IA, USA
fDate :
4/1/1996 12:00:00 AM
Abstract :
This paper proposes an implementation for vector quantizers (VQ) with very small codebooks (i.e., 30-32 codevectors) for compressing grayscale images. The technique uses a convex projections (CP) based algorithm for iterative restoration of edges, as part of the decoding process. The objective of this approach is to code the edge blocks vestigially by drastically reducing the number of edge vectors in a codebook. This will result in a large reduction in codebook size and hence fast searches. Also this method works better on images outside the training set since encoding is less dependent on the edges.
Keywords :
decoding; edge detection; image coding; image restoration; iterative methods; vector quantisation; algorithm; codebook size reduction; codevectors; convex projections; decoding process; edge blocks coding; edge recovery; grayscale image compression; iterative edge restoration; low bit rate VQ; training set; vector quantizers; very small codebooks; Bit rate; Fourier transforms; Gray-scale; Hilbert space; Image coding; Image restoration; Iterative algorithms; Iterative decoding; Pixel; Reproducibility of results;
Journal_Title :
Signal Processing Letters, IEEE