Advanced video processing techniques in video transmission systems.
详细信息
文摘
In this dissertation,we address four processing techniques in a video transmission system. First,we propose a homogenous video retargeting approach to dynamically adapt the video from a large resolution to a small one,keeping the interesting contents without introducing artifacts. We then design a video summarization system to summarize a long video into a shorter version,allowing viewers to access content more efficiently. The experiments of the proposed retargeting and summarization approaches show performance gain over existing solutions. For the events of video packet loss during transmission,we propose a perceptual quality model that mimics the human response scores after watching the impaired videos. Based on discovering the visual psychological factors that directly relate to the human scores,the perceptual quality model achieves better correlation with the true human response. Finally,we address the perceptual quality based rate-distortion optimization problem in the encoder design. We propose a piecewise approximation method to find out a rate distortion (perceptual) model,based on which the best rate-distortion trade-off is achieved.