DWT Algorithm Implementation for Image Compression using VLSI

摘要

Image compression is very important in order to reduce storage need. An image is represented as a two dimensional array of coefficients. The best image quality at a given bit-rate (or compression rate) is the main goal of image compression. Image compression may be lossy or lossless. The DWT has the two properties of no blocking effect and perfect reconstruction of the analysis and the synthesis wavelets. The discrete wavelet transform (DWT) has recently received considerable attention in the context of image compression due to its flexibility in representing nonstationary image signals and its ability in adapting to human visual characteristics. It has also been adopted by the next generation image compression standard known as JPEG 2000, due to its superior rate-distortion performance as compared to DCT.The Discrete Wavelet Transform (DWT), which is based on sub-band coding is found to yield a fast computation of Wavelet Transform. It is easy to implement and reduces the computation time and resources required. DWT is a suitable tool for extraction image features because it allows the analysis of image on various levels of resolution. The Wavelet transform is an alternative time frequency analysis technique compared to the traditional methods. The attractive features of DWT in image coding have conducted to significant interest in efficient algorithms for its hardware implementation.