Image Compression Using 2-d Multiple-level Discrete Wavelet Transform (dwt)

Wavelet is a recently developed compression technique in image compression. In this study, after multiple level 2-D wavelet transform of images, approximation and detail coefficients are obtained. These coefficients are quantized that more important coefficients are represented with higher accuracy and retained coefficients are represented with less accuracy or they are neglected. Afterward the quantized coefficient (symbols) are coded in a bit stream using recursive splitting Huffman coding. The quality of reconstructed images are measured with PSNR value, and compression ratio is calculated using given formula. Generally wavelet performs better compression than other compression methods.