Improving hybrid coding via control of quantization errors in the spatial and frequency domains

We propose new techniques to improve hybrid coding of images and video, without increasing decoder complexity, by controlling quantization effects in spatial and frequency domains, and finding optimal quantized coefficients via optimization. Additional compression is achieved by finding sets of optimal parameters, determined using training techniques. Experimental results confirm that the new method is able to provide better compression, both in objective measures, like signal-to-noise ratios, and also subjective, by reducing visually annoying blocking and banding artifacts.