Exploring Discrete Cosine Transform for Multi-resolution Analysis

• Main Author: Abedi, Safdar Ali Syed
• Format: Others
• Published: Digital Archive @ GSU 2005
• Subjects: Discrete cosine transform; Modified discrete cosine transform; Noise reduction; Multi-resolution analysis; Computer Sciences
• Online Access: http://digitalarchive.gsu.edu/cs_theses/12; http://digitalarchive.gsu.edu/cgi/viewcontent.cgi?article=1011&context=cs_theses

Multi-resolution analysis has been a very popular technique in the recent years. Wavelets have been used extensively to perform multi resolution image expansion and analysis. DCT, however, has been used to compress image but not for multi resolution image analysis. This thesis is an attempt to explore the possibilities of using DCT for multi-resolution image analysis. Naive implementation of block DCT for multi-resolution expansion has many difficulties that lead to signal distortion. One of the main causes of distortion is the blocking artifacts that appear when reconstructing images transformed by DCT. The new algorithm is based on line DCT which eliminates the need for block processing. The line DCT is one dimensional array based on cascading the image rows and columns in one transform operation. Several images have been used to test the algorithm at various resolution levels. The reconstruction mean square error rate is used as an indication to the success of the method. The proposed algorithm has also been tested against the traditional block DCT.