Suggested hybrid Transform Technique for image compression

Ismael Hadi challoob; Rasha Riyadh Mahmood

Ismael Hadi challoob Middle Technical University \Technical College of Management - Baghdad
Rasha Riyadh Mahmood Middle Technical University \Technical College of Management – Baghdad\Information

Keywords: Image compression, Discrete Cosine Transform, Discrete wavelet Transform, Slantlet Transform, CR, PSNR, MSE, UQI, SSIM

Abstract

Digital images are used in several domains. Large amount of data is necessary to represent the digital images such data needs large transmission bandwidth for the transmission over the network and also require storage capacity. Hence the data in the images should compressed by extracting only the visible elements. The image compression technique can reduce the storage and transmission costs. Image compression techniques should also maintains the quality of images. This paper proposes hybrid image compression technique which combines Discrete Cosine Transform (DCT) with Slantlet Transform (SLT). Several methods such as Discrete Cosine Transform (DCT), is used for compressing the images. But, these methods contain some artifacts. In order to overcome this difficulty and compress the image efficiently, a combination of DCT and SLT is proposed. Firstly Transform the image to frequency domain by applying SLT and decompose it into three levels, then DCT is applied on LL3.The results indicate that hybrid (SLT-DCT) technique offers superior compression performance compared to hybrid (DWT-DCT) based approaches. Their performance is evaluated in terms of Peak Signal to Noise Ratio (PSNR), Mean Square Error (MSE), UQI, SSIM and Compression Ratio (CR).