A Comparative Study of Image Compression Algorithms

Digital images in their uncompressed form require an enormous amount of storage capacity. Such uncompressed data needs large transmission bandwidth for the transmission over the network. Discrete Cosine Transform (DCT) is one of the widely used image compression method and the Discrete Wavelet Transform (DWT) provides substantial improvements in the quality of picture because of multi resolution nature. Image compression reduces the storage space of image and also maintains the quality information of the image. In this research study the performance of three most widely used techniques namely DCT, DWT and Hybrid DCT-DWT are discussed for image compression and their performance is evaluated in terms of Peak Signal to Noise Ratio (PSNR), Mean Square Error (MSE) and Compression Ratio (CR). The experimental results obtained from the study shows that the Hybrid DCT- DWT technique for image compression has in general a better performance than individual DCT or DWT.