Design of a Telepathology Model Utilising JPEG For Compression of Medical Images

Abstract

The specific objectives of the research were to examine the efficacy of Discrete Cosine Transform(DCT) as an image compression algorithm using the Joint Photographic Expert Group (JPEG) standard; and determine the suitability or otherwise of application of DCT on images required for Collaborative Pathological diagnosis. Seven histological images acquired with the use of Digital microscope from the University of Alberta, Canada were sent by e-mail by the Lead Pathologist to the researcher in Nigeria. These were compressed using GNU Image Processing software (GIMP, a third party freeware) at 25% and 50% factor and presented randomly to researchers along with a questionnaire. Ten responses were received and analysed using simple percentage and tabulation. The result showed that JPEG is efficient in compression of medical images because the images compressed at 25% factor were reduced from between 22% - 32%. The ones compressed at 50% factor were reduced between 15% - 20% which revealed that though the JPEG algorithm does not reduce images literarily based on the factor of reduction, size reduction is still significant. Furthermore, from the responses of the Participating Pathologist on the seven cases compressed at 25% factor, nine of the participating Pathologist agreed with the owner on the suitability of the compressed image for diagnosis for Case 1 and Case 2; as such the degree of confidence was 90%. In Cases 3, 4, 5, 6, and 7 all the 10 participating Pathologist agreed with the owner’s opinion; that is 100% degree of confidence. For images compressed at 50% factor, the ten participating Pathologists all agreed with the Owner’s opinion on the compressed images for Cases 1, 2, 3, 4, 5, 6 and 7 thereby giving a 100% degree of confidence in all the cases examined. The conclusion therefore is that the DCT is an efficient image compression algorithm and that using JPEG for telepathology systems is not only suitable but desirable because of the various practical usefulness to providing cost effective pathology services to the rural areas of the developing world.