Low Power and Area Efficient Approximate 2D-DCT Architecture for Wireless Capsule Endoscopy
Vaibhavi Solanki, Rahul Ranjan Kumar, Praveen Ghagare, Anand D. Darji · 2022
Wireless Capsule Endoscopy (WCE) is an efficient method to diagnose the Gastrointestinal Tract for determining various digestive diseases accurately. WCE module requires low power Discrete Cosine Transform (DCT) architecture for image compression because the transmission of the image data consumes about 90% of the total battery power. The image data should be compressed initially to reduce the power of the image data to be transmitted and the communication bandwidth without affecting the image quality significantly as the physician may apply the zooming effect to perform a detailed diagnosis. Without proper clarity in the images, it will be very difficult for the physician to diagnose the disease. Therefore, an optimized image compression algorithm is required to maintain the sufficient video quality with low power consumption. This paper introduces an approximate DCT architecture with approximate coefficients for low power consumption. The proposed design is multiplier-free as it uses shift and add architecture for the implementation of a multiplier. An inexact adder is also introduced in the two-dimensional DCT (2D-DCT) architecture to achieve better performance in terms of power, area and delay. It achieves the performance improvement due to approximation of DCT coefficients and inexact adders. The proposed design is implemented using Verilog HDL and synthesized in Synopsys Design Compiler using Faraday’s 180nm technology library. It achieves about the reduction of 9.4%, 47.17% and 8.36% in area, power and delay respectively compared to the most recent existing design.