Abstract
In general, image compression is the best way to decrease the communication bandwidth and save the transmission power. However, due to power and size limitation, traditional image compression techniques are not appropriate, therefore, more special techniques are required. So, the image compressor should be able to sufficiently compress the captured images to save the transmission power, retain reconstruction quality for an accurate diagnosis and should also take a small physical area. To meet all these conditions, we proposed an efficient hardware architecture of Cordic based Loeffler DCT compression algorithm designed for wireless endoscopic capsule. Our improvement over the original algorithm concerns the cordic part. This allowed us to reduce the number of addition from 38 to 30 add operations in the main algorithm whereas the shift operations number remain constant (16 shift operations). Moreover, to further ameliorate our results, we used Modified Carry Look Ahead adder (MCLA) and Carry Save Adder (CSA) which are characterized by low power and high speed compared to classical Carry Look Ahead Adder (CLA). Our aim is to provide an optimized architecture in terms of area and power consumption all in accordance with the image quality. The proposed design was implemented on (Field Programmable Gate Arrays) FPGA. Compared to other architectures; the proposed architecture has not only reduced the computation complexity, but also the area and power consumption. It should be noted that the proposed DCT architecture is very suitable for low power and high-quality codecs, that granted the image quality and this is proved by a software implementation using Matlab, especially for battery-based systems.