A Low-Power Color Mosaic Image Compressor Based on Optimal Combination of 1-D Discrete Wavelet Packet Transform and DPCM for Wireless Capsule Endoscopy
Kinde Anlay Fante, Basabi Bhaumik, Shouri Chatterjee · 2015
A novel low-power endoscopic image compressor is designed that occupies small silicon chip area, gives a high compression rate and maintains acceptable image quality. By utilizing unique properties of human gastrointestinal tract images, computationally simple and elegant methods are employed. The employed methods are lifting scheme based two level 1-D discrete wavelet packet transform, uniform quantization, chrominance component sub-sampling, differential pulse code modulation and Golomb-Rice entropy encoder. All the modules are highly optimized from computational complexity, efficiency and memory requirement perspectives. The proposed algorithm requires neither demosaicking nor de-interleaving operations that require large memory and consume a significant amount of power. The proposed image compression scheme achieves a compression rate of 81.31 % with peak signal to noise ratio of 39.45 dB. The implementation of the algorithm in 130 nm standard CMOS process technology occupies a core area of 0.342 mm×0.342 mm. It consumes 48.4 I¼W of power for encoding two color mosaic frames, with a resolution of 512×512, per second. The proposed endoscopic image compression scheme gives a power consumption reduction of about two orders less than the realizations proposed in literature.