Imprecise 4-2 compressor design used in image processing applications

Approximate computing can be used in the error-tolerant applications since it can provide meaningful results with lower power consumption. In this study, the authors proposed a novel imprecise 4-2 compressor which is used in the multipliers of image processing applications. Besides the output values, they also consider the pattern distribution to resynthesise the 4-2 compressor in imprecise style. Compared to the precise compressor, the proposed imprecise 4-2 compressor can reduce power consumption and delay by 56 and 39%. Compared to the precise multiplier, the simulation results show that the multiplier which uses the proposed imprecise 4-2 compressor can achieve 33 and 30% improvement in power consumption and delay, respectively. In addition, the image quality of their design is good for human perception because peak signal-to-noise ratio PSNR values are more than 33 and mean structural similarity values are more than 0.99. Even compared to the related imprecise works, their design has a better error rate to improve the quality of images while maintains both the high power efficiency and low circuit complexity.