An Energy-Efficient Approximate DCT for Wireless Capsule Endoscopy Application

摘要

Wireless capsule endoscopy is widely used as an efficient way to receive images of gastrointestinal tract for medical diagnostics. Due to its energy compaction property for correlated image pixels, DCT) is highly preferred in image compression for this real time application. To accommodate the tight power budget and small size condition in the wireless capsule endoscopy application, an energy efficient DCT based on CMOS implementation is proposed in this paper. Three approximating methods are combined and applied in a multiplier-less DCT architecture. The simulation results indicate that the proposed DCT reduces 53.85% energy and 25.32% area with a PSNR penalty of 1.9dB when compared with the integer DCT. Compared with CORDIC-Loeffler DCT, it achieves 19.38% reduction on energy dissipation and 14.4dB more PSNR at the cost of only 1.39% area overhead.