Comparison of the effect of lossy compressions with the modulation transfer function

摘要

Abstract: The purpose of this study was to examine the effects of lossy image compression on the quality of digital radiographic images and to compare the resolution properties of the three image compression algorithms (JPEG) on digital radiographic images using the Modulation Transfer Function (MTF). A single point source of Tc$+99m$/ was scanned by a Gamma camera and its image was compressed by JPEG, wavelet and fractal algorithms at various compression levels. The PSFs for the original and compressed images were generated in Matlab 5.0. This was done by analyzing the pixel values along a direction through the center of the point source on each image. The MTF for each image was then calculated by Fourier transform of its PSF. The resolution properties of each compression techniques were presented. It has been found that the resolution properties of the compressed levels and algorithms are not straightforward. !20