1. BLOCK MOTION ESTIMATION USING ADAPTIVE PARTIAL DISTORTION SEARCH Yui-Lam Chan, Wan-Chi Siu and Ko-Cheung Hui Centre for Multimedia Signal Processing Department of Electronic and Information Engineering The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong ICIP 2002

3. Accumulated partial distortion

5. Sub-sampling PDS (SSPDS)

6. Speed up of the PDS How fast the computation of the accumulated partial distortion is stopped. The proposed technique –Based on the fact that high activities in pixels contribute most to the MAD criterion.

7. Representative pixels The representative pixels in the block –Pixel with high activities Edges Texture

8. Hilbert scan and its features Pass through all the grid points only once in a 2-D space. –1891, German mathematician Hilbert The edge info. In a 2-D image is preserved in its 1-D Hilbert-scan sequence more effectively than the raster scan which may miss edges due to its scanning direction.

9. 16x16 blockHilbert scanRaster scan Yankang Wang, Yanqun Wang and H. Kuroda, “A globally adaptive pixel-decimation algorithm for block-motion estimation, “ IEEE Trans. On Circuits and Syst. For Video Tech., Vol. 10 pp.1006-1011, Sept. 2000.

10. The Hilbert scan

11. The proposed APDS Algorithm

13. An example of formatting a final sorted sequence, hs’

15. The proposed APDS Algorithm

16. Simulation Results Average operations per block for different sequences. A speed up about 1.96 to 4.73 4.73 1.96 3.45 3.76

17. Simulation Results Frame-by-frame comparison of average operations per block in the “Salesman” sequence.