Image compression technique

Digital images generally contain significant amounts of spatial and spectral redundancy. Spatial redundancy is due to the correlation between neighboring pixel values, and spectral redundancy is due to the correlation between different color planes. Image compression (coding) techniques reduce the number of bits required to represent an image by taking advantage of these redundancies. An inverse process called decompression (decoding) is applied to the compressed data to get the reconstructed image. The objective of compression is to reduce the number of bits as much as possible, while keeping the resolution and the visual quality of the reconstructed image as close to the original image as possible. This article gives an overview of the major image compression techniques. The decoding steps for most of the coding schemes are quite intuitive and are usually the reverse of the encoding steps