Low-Bitrate Video Coding using Adaptive Wavelet Quantization of Difference Image

摘要

This paper presents a simple and effective image coding method that is well adaptive to close-range video transmission because of its low bit rate and simple coding procedure. At first, it reduces temporal redundancies by performing image DPCM between previous frame and current frame, and makes wavelet transformed image of this difference image. Then, the coefficients are quantized selectively by using the coefficient values of base level and mid-frequency level because inter-level redundancies are widely exists in multi-resolution images. Finally quantized coefficients are made from the function that implies the target bit rate, the average coefficient energy, and the value of the level. The proposed method shows the effective performance in the experiments using the continuous motion images and transition images.