Power-optimized log-based image processing system

Abstract

The continuous development of devices such as mobile phones and digital cameras has led to a higher amount of research being dedicated to the image processing field. Today's image-acquiring tools require battery-operated power, and hence, power optimization becomes a major factor to be considered in the hardware implementation of image systems. This paper proposes an image processing system which utilizes set partitioning in hierarchical trees (SPIHT)-integrated discrete wavelet transform (DWT) structure for image processing. The overall advantage of this proposal is achieved by modifying the arithmetic units in the DWT structure. Utilizing a logarithm-based floating point unit (FPU) in the DWT computation structures, the logarithmic number system (LNS) adaptation in the arithmetic unit results in overall accuracy enhancement with reduced area and power consumption. To ensure the versatility of the proposal and for further evaluating the performance and correctness of the structure, the model is implemented using Xilinx and Altera field-programmable gate array (FPGA) devices. The analyses obtained from the implementation show that the structure incorporated with the log-based FPU is 25% more accurate with 47% reduced power consumption than the integer-styled FPU incorporated DWTs, along with enhanced speed and optimal area utilization.