Image Compression Based On Modified Walsh-Hadamard Transform (MWHT)
Image compression techniques are used for reducing the amount of data required to represent a digital image. An image can be compressed with the use of Walsh-Hadamard Transform (WHT), quantization and encoding steps in the compression of the JPEG image format. In this system, RGB components of color image are converted to YCbCr. For image quantization, YCbCr color space is more convenient than RGB color space. The original image is broken into 8×8 blocks of pixel. In this system, the proposed method is mainly performed by modifying Walsh-Hadamard transform (WHT) method to optimize the processing time of image compression. Each block is calculated by using the modified Walsh-Hadamard Transform (MWHT). Then image quantization calculates probability index for each unique quantity. After applying quantization, Huffman code for each unique symbol is calculated so as to compress the image using Huffman compression. The main objective of this system is to decrease the transmission time for transmission of images. Experimental result shows that the result of the performances for the proposed method of BMP and GIF images is compared. So, the performances are evaluated in term of Bit Per Pixel (BPP), Compression Ratio (CR), Compression Time (CT). The system is implemented by using C# programming Language.
Index Terms- Huffman encoding, Image compression, Modified Walsh-Hadamard Transform (MWHT), Quantization, YCbCr.