Research on Key Technologies for Image Compression and Transmission in Telemedical System
|School||Harbin Engineering University|
|Keywords||DICOM H.264 RTP/RTCP protocol image compression video transmission|
Telemedical is a new type of medical service, which plays a more and more important role in medical activities, so it has very important realistic significance for research on key technologies of telemedical. In order to solve key technologies such as data transmission, video communication and data storage, compression and transmission of DICOM medical images and video images is researched in this thesis.The size of DICOM image files is commonly large, so it is not suitable for transmission and storage. In this thesis, firstly the format of DICOM files is researched and then pixel information is extracted to prepare for image compression. In order to improve image quality. quantization factor is brought in this thesis to image compression, so we can change quantization factor value to improve image quality. Part of the DICOM files is saved to text file because it is not image and can’t be compressed, at last, compose the compressed image and text file to be the DICOM standard format. C-STORE service of DICOM standard is realized by using VC++. Because we use DICOM protocol to transmit images, this function can be conveniently integrated into PACS or HIS system and can reduce production cost and raise developing efficiency.Remote video is an important part of telemedical. We select H.264 video image as researching object, realize encoding, decoding, storage and remote transmission of 11.264 video. The usage of DirectShow streaming technology effectively reduces developing time on encoding, decoding and storage of H.264 video. Double-buffering and AIMD algorithm can improve video quality, especially in low band network. Double buffer is allocate tow memory blocks at SCU and SCP, captured data at SCU firstly stored to the first memory block, and then the second, and send data to SCP; when data received, it doesn’t play the data immediately but wait for the first block is full, store the received data to the second block.The research on DICOM images offers a very good solution for transmission and storage of medical data, and can provide effective help for remote diagnosis. Offline storage medical data can be consulted by doctors to improve their medical skills. The research on video encoding, decoding and transmission can provide convenient communication between doctors and patients, which is also benefit for remote teaching observation. In addition. mainly research of this thesis is based on software, so the low cost is beneficial for the extension of telemedical to middle and small hospitals.