Telemedicine System In The Image Compression Algorithm

It is possible to store large quantity of medical image with the development of computer technology and application of image compression technology. It settled a basis for the new development of telemedicine with the establishment of DICOM standard and rapid development of network technology. In view of the characteristic of medical image, we must get good quality image and complete relative medical image to ensure the diagnostic correctness. Nevertheless the existing network bandwidth restricts the rapid transmission of medical information. So the compression of medical image and communication of diagnosis data is still a hot and key problem to study.The image compression and coding method developed soon from entropy coding, predictive coding, transformation coding to new vector quantization coding, fractal image coding, wavelet coding etc. Using the image coding method directly cannot solve the contradiction between high compression ratio and good quality image. Recently by way of a math theory wavelet transform catches more attention, which has good orientation quality in both spatial domain and frequency domain. The two-dimensional image is decomposed into three class and the author analyzed the coefficients in every sub image, studied the impact of the coefficients for construction image in different frequency sub band and different region, studied the impact for the construction image discarding different frequency wavelet coefficients simultaneously. The conclusion we get is: the low frequency image contains the majority image information; the wavelet coefficients in high frequency sub band distribute near the zero values symmetrically; more higher the frequency is, more smaller the range of coefficients distribute and more smaller the contribution is for the construction image. In view of the characteristic of wavelet coefficients, we can get high compression ratio quantizing and coding the coefficients in different frequency sub band. Commonly the doctor is only interested in a certain region, so we presented an independent coding technology for the interested region with lossless compression method and the other region with lossful compression method.DICOM is an international standard for medical information transmission, so the medical image compression technology must follow the standard in the future. In this paper, after the general content of DICOM standard is briefly introduced, we put forward a method to adjust the image color according to the human eye's vision characteristic. And we studied the method to transform DICOM image to BMP image.In this task, the study to wavelet coefficients is helpful for searching better image compression and coding method in telemedicine system. The discussion for DICOM standard is helpful for searching a method to transform DICOM image to BMP image. The existing DICOM standard will be more perfect combining with new compression technology. So the study to this task is valuable in theory and application field.