FPGA Implementation of Approximate 2D Discrete Cosine Transforms

M Thiruveni Raguraman,D Shanthi Saravanan

doi:10.4236/cs.2016.74037

Abstract

Discrete cosine transform (DCT) is frequently used in image and video signal processing due to its high energy compaction property. Humans are able to perceive and identify the information from slightly erroneous images. It is enough to produce approximate outputs rather than absolute outputs which in turn reduce the circuit complexity. Numbers of applications like image and video processing need higher dimensional DCT algorithms. So the existing architectures of one dimensional (1D) approximate DCTs are reviewed and extended to two dimensional (2D) approximate DCTs. Approximate 2D multiplier-free DCT architectures are coded in Verilog, simulated in Modelsim to evaluate the correctness, synthesized to evaluate the performance and implemented in virtexE Field Programmable Gate Array (FPGA) kit. A comparative analysis of approximate 2D DCT architectures is carried out in terms of speed and area.

Highlights

The increase in use of computers increases the use of digital signal processing (DSP)
A Discrete Cosine Transform (DCT) [1] gives a finite number of points in terms of addition of cosine functions oscillating at different frequencies
We proposed 1) VLSI Architectures for Approximate 2D Discrete cosine transform (DCT) and 2) hardware implementation of proposed approximate 2D DCT transforms

Summary

Introduction

The increase in use of computers increases the use of digital signal processing (DSP). In DSP, three domains are used to represent the signals. Due to its strong “energy compaction” property DCT is frequently used in signal and image processing. It is used in a multitude of compression standards. (2016) FPGA Implementation of Approximate 2D Discrete Cosine Transforms. Approximation of DCT transform becomes efficient by the vast improvement in fast algorithms. A Discrete Cosine Transform (DCT) [1] gives a finite number of points in terms of addition of cosine functions oscillating at different frequencies. Image and video signal needs 2D-DCT for its handling. The computation of 2D-DCT from 1D-DCTs across all dimension is known as a row-column algorithm.

Methods and Materials

One-Dimensional Digital Architectures of Approximate DCT

Two Dimensional Approximate Transform

FPGA Implementations and Discussions

Findings

Conclusion