A Study of Frequency Component Motion Estimation and Deformable Mesh Video Coding

• Main Authors: Chou, Yung-Ming, 周永銘
• Other Authors: Hsueh-Ming Hang, Wen-Thong Chang
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/64937177067598449643

博士 === 國立交通大學 === 電子工程學系 === 85 === Motion estimation techniques are widely used in today''s video processing systems. The most frequently used techniques are the block matching and the differential method. In the first part of this thesis, we have studied this topic form a viewpoint different from the above to explore the fundamental limits and tradeoffs in image motion estimation. The underlying principles behind two conflict requirements in motion estimation, accuracy and ambiguity, become clear when they are analyzed using this tool --- frequency component analysis. This analysis also suggests new motion estimation algorithm and ways to improve the existing algorithms. Ths so-called frequency component motion estimation algorithm is thus proposed. Comparing to the conventional block matching and phase correlation algorithms, this approach provides more reliable displacement estimates particularly for the noisy pictures. In a conventional motion- compensated coding scheme, images are often partitioned into artificial units such as rectangular blocks. Without considering the natural spatio-temporal structure of images and the characteristics of human visual system, the performance of block based motion compensation is often limited by this fundamental restriction. In addition, this coding structure does not match the object scalability requirement which is a new trend in video coding. Thus, in the second part of this thesis, we develop several techniques to form a new deformable mesh video coding algorithm. These techniques include foreground/ background separation, nodal point tracking with overlapped patch elimination, and nonrectangular DCT coding schemes. The simulation results indicate that this coding structure is quite suitable for object scalable coding at low bit rates.