Perceptual coding for a super high-definition video based on subjective assessment of viewing distance

Very high-resolution video systems, such as 4K (3840×2160), enable a very close viewing distance that is almost the same as the picture height. This technology enables high-reality systems in homes to be realized. However, the very short distance causes significantly different views across the picture, and uniform processing for the picture may not always be the best choice. Here, we calculate the actual view size of a pixel, which depends on the pixel position in close viewing. We proposed the perceptual coding methods using pre/post-processing for the picture to be coded. It is a quantization control by a contrast change. However, the control of quantization should be decided based on the perceptual performance between pixel size and quantization. Therefore, we carried out subjective assessment about this. The bit rate reduction is checked for each method. The 4K resolution processing is realized by four patterns of HDTV picture coding with AVC. As the results of these experiments, it is recognized that the bit rate reduction 15 percent by the optimal coding.