Low-power VLSI design for motion estimation using adaptive pixel truncation

Abstract

Power consumption is very critical for portable video applications such as portable videophone and digital camcorder. Motion estimation (ME) in the video encoder requires a huge amount of computation, and hence consumes the largest portion of power. In this paper, we propose a novel method of reducing power consumption of the ME by adaptively changing the pixel resolution during the computation of the motion vector. The pixel resolution is changed by masking or truncating the least significant bits of the pixel data, which is governed by the bit-rate control mechanism. Experimental results show that on average more than 4 bits can be truncated without significantly affecting the picture quality. This results in more than 60% reduction in power consumption.

Low power variable block size motion estimation using pixel truncation

“…Truncating pixels at a 16x16 block size results in acceptable performance as shown in the literature [2]. However, at smaller block sizes, the number of pixels involved during motion prediction is reduced.…”

“…From [2], pixels truncation for a 16x16 block size gives a small PSNR drop compared to untruncated pixels. At a 16x16 block size, there are 256 pixels involve in the matching calculation.…”

“…In motion estimation, pixel truncation has been used to reduce the computational load for matching calculation unit [1]. The authors in [2] implemented adaptive pixel truncation on the least significan bits (LSB). The number of truncated pixels is modified according to the quantisation parameter (QP) value.…”

Uma proposta de estimação de movimento para o codificador de vídeo Dirac

“…Esta etapa, entretanto, é, na maioria dos casos, bastante intensiva em complexidade computacionalde forma geral, uma compressão mais eficiente demanda mais processamento -, de modo que é essencial que sejam estudados estes trade-offs (1). A estimação de movimento é responsável por até 50% da computação encontrada em todo o sistema de codificação, sendo sua parte mais complexa (40).…”