Differential Contrast Based Adaptive Quantization for Perceptual Quality Optimization in Image Coding.

We consider the perceptual quality optimization in image coding through adaptive quantization. A differential contrast model is proposed to measure the visual sensitivity to the quantization distortions, and thereby deriving the spatially adaptive quantization strategy. A complementary quantitative approach is provided as a means to efficiently calculate the proposed differential contrast model. The resulting visual quality improvement is experimentally demonstrated.