Optimal nearly uniform scalar quantizer design for wavelet coding
C. Parisot, Marc Antonini, Michel Barlaud · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2002
Uniform scalar quantizers are widely used in image coding. They are known to be optimum entropy constrained scalar quantizers within the high resolution assumption. In this paper, we focus on the design of nearly uniform scalar quantizers for high performance coding of wavelet coefficients whatever the bitrate is. Some codecs use uniform scalar quantizers with a zero quantization bin size (deadzone) equal to two times the other quantization bin sizes (for example JPEG2000). We address the problem of deadzone size optimization using distortion rate considerations. The advantages of the proposed method are that the quantizer design is adapted to both the source statistics and the compression ratio. Our method is based on statistical information of the wavelet coefficients distribution. It provides experimental gains up to 0.19 dB.