Space-Frequency Quantization for Image Compression With Directionlets

Space-frequency quantization for wavelet image coding

A new class of image coding algorithms coupling standard scalar quantization of frequency coefficients with tree-structured quantization (related to spatial structures) has attracted wide attention because its good performance appears to confirm the promised efficiencies of hierarchical representation. This paper addresses the problem of how spatial quantization modes and standard scalar quanti...

Vector Quantization for Image Compression-Concept Quantization

Progressive trellis-coded space-frequency quantization for wavelet image coding

This paper addresses progressive wavelet image coding within the trellis-coded space-frequency quantization (TCSFQ) framework [1]. A method similar to that in [2] is used to approximately invert TCSFQ when decoding at rates lower than the encoding rate. Our experiments show that the loss incurred for progressive transmission is within 1 dB in peak signal-to-noise ratio and that the progressive ...

Wavelet packet image coding using space-frequency quantization

We extend our previous work on space-frequency quantization (SFQ) for image coding from wavelet transforms to the more general wavelet packet transforms. The resulting wavelet packet coder offers a universal transform coding framework within the constraints of filterbank structures by allowing joint transform and quantizer design without assuming a priori statistics of the input image. In other...

Modified Vector Quantization Method for Image Compression

A low bit rate still image compression scheme by compressing the indices of Vector Quantization (VQ) and generating residual codebook is proposed. The indices of VQ are compressed by exploiting correlation among image blocks, which reduces the bit per index. A residual codebook similar to VQ codebook is generated that represents the distortion produced in VQ. Using this residual codebook the di...