Analysis of Image Compression Methods using DCT and Wavelet Transform in Matlab

Image compression reduces the amount of data required to represent an image. To compress an image efficiently we use various techniques to decrease the space and to increase the efficiency of transfer of the images over network for better access. This paper explains about compression methods such as Discrete Cosine Transform (DCT), Discrete Wavelet Transform (DWT) , JPEG 2000, EZW and SPIHT (Set Partition in Hierarchical Trees) on the basis error comparison, mean square error, peak signal to noise ratio and compression ratio. Provides substantial improvements in the quality of picture because of multi resolution nature. DWT is multi resolution in nature. So, it provides substantial improvements in the quality of picture. Image compression reduces the memory storage space of image and also maintains the quality information of the image. In this paper we have analysed some wavelet based compression techniques like Embedded Zero tree Wavelet (EZW), Set Partitioning in Hierarchical Trees (SPIHT) and JPEG2000. These techniques are analysed on lena image. The performance evaluation is made on the basis of parameters like PSNR, MSE and CR etc.