A new adaptive quantization method to reduce blocking effect

In this paper, we present a method to reduce the blocking effects in block based coding schemes. Based on our observations, the blocking effect appears mainly in the regions where motion is so fast or complex that its motion is not well compensated. These regions tend to be coarsely quantized in the traditional method using only the spatial activity measure. In order to apply fine quantization on these regions, we introduce a new activity measure, the slope activity. By using this measure together with the spatial activity measure, we can perform an adaptive quantization on each macroblock in a picture. Our approach shows better picture quality compared to the MPEG2 TM5. Particularly in fast or complex motion scenes, the blocking effect in the object boundaries are far more reduced than that of MPEG2 TM5, therefore generating a much smoother image for comfortable viewing. Also, our method shows a higher PSNR than that of the MPEG2 TM5.