Low-Voltage Low-Power Image Motion Estimation Circuit Design

• Main Authors: Sheng Hung Yu, 游勝鴻
• Other Authors: I. C. Wey
• Format: Others
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/78362255008263245428

碩士 === 長庚大學 === 電機工程學系 === 101 === In this thesis, we present a novel low power video motion estimation circuit to reduce the power consumption of the circuit and maintain the normal operation in a low-voltage environment by shortening the delay of operator. To achieve this goal, we present two architectures, which are Relax-ME and XOR-ME designs. In the Relax-ME architecture, an approach to split operation units is employed in order to divide the main arithmetic unit of the image motion estimation circuit into the upper and the lower significant-bit parts. These two parts simultaneously compute in the same clock cycle independently; thereby, the computation delay can be reduced significantly, so the video motion estimation circuit can operate in a low-voltage environment with lower power consumption. The segmentation of arithmetic units is done by modifying the original structure without adding any additional redundant circuit; accordingly, the hardware overhead of motion estimation circuit can be lowered and image quality of the video motion estimation circuit can be retained with no PSNR degradation. In the XOR-ME architecture, the computation of the major SAD arithmetic unit is improved by replacing the long-path-delay adder with the short-path-delay counters and comparators to maintain the normal operation in a low-voltage environment without any additional redundant circuit as well. In order to further reduce the power consumption of the ME circuit, an early termination method is proposed in both Relax-ME and XOR-ME architectures to omit unnecessary search calculations and save more power. Comparing the proposed Relax-ME and XOR-ME with the ISR-ANT ME design, the hardware overhead area in the proposed low-power video motion estimation circuits can be reduced by 23.25% and 30.05%, respectively. The power consumption in the proposed Relax-ME and XOR-ME designs can also be further saved by 42.18% and 49.11% respectively while comparing with the ISR-ANT ME design that all operate under low voltage supply environment and still met the motion estimation system PSNR performance requirement.