A Modified Quantization Based Image Compression Technique using Walsh-Hadamard Transform

A new quantization table using the nearest maximum common prime factor is generated for image compression using Walsh-Hadamard Transform (WHT). Image compression is important for many applications that involve huge data storage and transmission such as multimedia, video conferencing and medical imaging. In the proposed system, RGB components of color image are converted to YCbCr color image. Then an image is divided into 8x8 pixel block for each block. WHT based image compression is used to lossy image compression. The prime based new quantization table is created to reduce the quantization error (QE) bit in the quantization step. After the image is quantized, Huffman coding is a technique for representing the quantized coefficients as compactly as possible. The reverse process takes place for image decompression. The image compression system using WHT, standard quantization table, Huffman coding is also created. The performances are compared between original system and proposed system using performance parameters such as Compression ratio, Bit Per Pixel, Mean Square Error, Peak Signal to Noise Ratio and Time.