|Budget Amount *help
¥4,000,000 (Direct Cost : ¥4,000,000)
Fiscal Year 1999 : ¥2,000,000 (Direct Cost : ¥2,000,000)
Fiscal Year 1998 : ¥2,000,000 (Direct Cost : ¥2,000,000)
For fast MPEG-2 encoding, a fast motion-estimation (ME) algorithm, called the "breaking-off-search (BOS)" algorithm, was developed in 1998. The number of computations is drastically reduced by introducing computational constraints in a conventional fun-search (FS) algorithm. By improving the BOS algorithm, "modified breaking-off-search (MBOS)" was also developed in 1999. The MBOS algorithm with threshold values, which are adaptively assigned, can increase processing speed by a factor of 3.4. It can not only keep the same visual quality as that of the FS method, but can sometimes achieve a higher PSNR than FS. The MBOS algorithm can eliminate serious degradations of picture quality and speed associated with BOS due to the presence of scene changes. Furthermore, a drastic speed improvement substantially reduces the power dissipation of the ME array. A 40.5-MHz, 2.5-V, ME test chip using the MBOS method was fabricated by using the 0.6-μm CMOS process. The measured power dissipation was reduced to 410 mW, which is about 1/14 that of the ME-array using FS.