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DCTlab – DIDACTIC TOOL FOR THE STUDY OF IMAGE COMPRESSION

Current standards for the compression of still and moving images use Discrete Cosine Transform (DCT) which represents an image as a superposition of cosine functions with different discrete frequencies. Students and engineers specializing in image and video systems engineering need to understand why DCT is necessary and to understand the influence of DCT based image compression on picture quality. Therefore, education software "DCTlab" for the analysis of DCT application in image compression systems is developed. DCTlab is a library of MATLAB routines for DCT image compression with graphical user interface. DCTlab includes tools for spatial-frequency image analysis and procedures for image quality evaluation. The user can specify input image and compression parameters such as compression ratio or image quality. The compression results can be assessed and visual image quality of input and reconstructed image can be compared.