Gray Scale Image Compression

Abstract: The process of reducing the size of a data file is referred to as data compression. Compression is useful because it helps in resources usage reduction, such as data storage space or transmission capacity over internet. Image compression is a main technology in transmission and storage of images and scanned documents, because of large amount of data and information is associated with them. This paper proposes a compression technique for scanned documents and images, based compression method using discrete wavelet transformation (DWT), Discrete Cosine Transformation, (DCT) and Code Book Vector. The importance of the DCT in an image compression is that it takes correlated input image and concentrates its energy in just the first few transform coefficients. This feature of DCT makes it useful in data compression. The effectiveness of the algorithm has been justified over some real images and scanned documents. The performance of the proposed algorithm has been compared with other common compression algorithm.

Keywords: Discrete Wavelet Transformation (DWT), Discrete Cosine Transformation (DCT), Code Book Vector, Customized file format, JPEG images.