Methods for performing video quality evaluations in the field of medicine

As for the evaluation method of the motion picture compression, the International Telecommunication Union has issued some technical Recommendation. However, the tendency of the Recommendation doesn´t penetrate into telemedicine field to perform a remote medical diagnosis. Roughly, there are two kinds of classification about the evaluation of motion picture compression, subject and objective evaluation. The subject evaluation that ITU recommended shall be performed only with the eyes of the users. In general, when motion picture compressed with the discrete consine transform, the stream of the picture is consisted by each frame with the different quality, such as I-picture, P-picture, and B-picture. The I-picture is coded with full image information and independent from other frames, and P and B picture has only information of the difference from the I-picture. Due to this combination of three kinds of pictures, we have to evacuate the motion picture with subjective methods. The authors intend to introduce ITUs four Recommendations such as Double-Stimulus Continuous Quality-Scale of ITU-R BT.500. Also, they explained the PSNR and J.144 as objective approach. The authors suggest that the distance between the display and the subject should be changed 2 H, 6 H units based on the actual environment of the clinical office. Finally, the authors expect the Japanese Telemedicine Association to create the picture library to perform its verification in each clinical filed and that makes great contribution to the compression technology and to the communication circuit management.