VLSI-Oriented Lossy Image Compression Approach Using DA-Based 2D-Discrete Wavelet

1Devangkumar Umakant Shah and 2Chandresh H. Vithlani
1Electronics & Communication Department, School of Engineering, R. K. University, Rajkot
2Electronics & Communication Department, Government Engineering College, Rajkot

Abstract: In this paper, we introduced a discrete wavelet transform based VLSI-oriented lossy image compression approach, widely used as the core of digital image compression. Here, Distributed Arithmetic (DA) technique is applied to determine the wavelet coefficients, so that the number of arithmetic operation can be reduced substantially. As well, the compression rate is enhanced with the aid of introducing RW block that blocks some of the coefficients obtained from the high pass filter to zero.  Subsequently, DPCM (differential pulse-code modulation) and Huffman-encoding are applied to acquire the binary sequence of the image. The functional simulation of each module is presented as well as the performance of each module is widely analyzed with gate required, clock cycles required, power, processing rate, and processing time. From the analysis, it is found that the DCM module requires more gates to do the transformation process compared to other modules. Eventually, the proposed compression approach is compared with the existing methods in terms of processor area and power. Comparative result shows that the proposed method offers good performance in power-efficiency corresponding to 0.328mW/chip than the prior methods.

Keywords: Image compression, Discrete Wavelet Transform, Distributed Arithmetic, Differential Pulse-Code Modulation (DPCM), Huffman-coding.

 

Received November 11, 2011; accepted May 22, 2012

  

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