Improved Bit Allocation for Transform Coding of Images
Patrick Kechichian, Dinh-Manh-Cuong Tran, Fabrice Labeau · 2006
In this paper, an algorithm is proposed to allocate quantizer levels to transform coefficients of image blocks that have been transformed using the Karhunen-Lo` eve Transform (KLT). This algorithm adjusts the well known bit allocation formula for a Gaussian source to compress natural images that in general, are not Gaussian. By varying the weight of the logarithmic term in the bit allocation formula, it is possible to obtain a higher PSNR for a given image at a specified desired bit rate. An additional interpretation of the effect of this weighting in terms of zonal bit allocations is provided.