A Study On Medical Image Compression Techniques

Abstract

Medical images play an important role in diagnosis and treatment newlineprocedures These medical images have high spatial and graylevel resolution newlinefor providing better diagnosis and hence generate large amount of data newlinecreating storage and transmission problems Compression of medical images newlinecould minimize storage space and allow fast transmission In this research newlinefive techniques have been proposed for the compression of medical images newlinewhich provide good compression ratio and also preserves the diagnostically newlinesignificant information Five different image modalities have been newlinecompressed using the proposed methods which include Magnetic Resonance newlineImaging MRI Computed Tomography CT Ultrasound US Coronary newlineAngiogram CA and Functional Magnetic Resonance Imaging fMRI The newlineproposed methods have been assessed through objective measures like Mean newlineSquare Error MSE Peak Signal to Noise Ratio PSNR etc and through newlinesubjective measures by the opinion of physicians in the corresponding field newlineThe proposed schemes have also been evaluated on comparison with existing newlinecompression standards like Joint Photographic Experts Group JPEG lossy newlineJPEG 2000 and also with the existing compression techniques for the newlinecorresponding medical image modality newlineA TwoDimensional 2D lossy compression algorithm using newlinebilinear interpolation has been proposed for medical images in Chapter 2 The newlineproposed method presents a technique for the classification of image blocks newlineas significant or insignificant on the basis of threshold value of variance The newlinecorner pixels of the blocks are stored and the remaining pixels are obtained by newlinebilinear interpolation The difference between the original and interpolated newlineimage is calculated and the difference is transmitted along with the bilinear newlinecoefficients At the receiving end images are reconstructed with corner newlinepixels The difference is added only to the significant blocks The newlineexperimental results show that the proposed technique yields better newlineperformance in terms of CR and PSNR compared to JPEG standard newlineA 2D lossy compression newline