The Research Of Key Techniques Of The Ray Imaging System Based On The Wireless Remote Control

The ray machine is connected with control side by cable in conventional X-ray inspection system at present, which greatly reduce the flexibility of equipment, and the adjustment of tube voltage and tube current by manual approach also reduces the detection efficiency of equipment. Based on the research of video coding technology and image processing, the ray imaging system based on the wireless remote control has been designed in the dissertation, which can achieve the remote wireless control of ray imaging system and the adaptive regulation of tube voltage and tube current to improve the flexibility and intelligence of radiation detection equipment .Firstly, the whole system structure, working principle and software functions of ray imaging system based on the remote wireless control have been introduced in detail. Video coding and decoding algorithm based on the MPEG-4 standard have been proposed to enhance the image transmission quality, and the video object extraction technique in the video coding has been researched emphatically. According to the characteristics of radiographic image, the imaging area of detected object is regarded as video object, and retractable coding based on bit plane is used to realize coding and decoding module. The experiment results show that the optimized system has better MTF performance, the video communication quality has been improved about 1dB, and the coding efficiency has been promoted using video object extraction technology.Secondly, the closed-loop control subsystem of X-ray machine has been designed to improve the level of intelligent system, which attain the adaptive control of tube voltage and current based on the ray image quality. On the basis of the image quality evaluation method, combined with X-ray image characteristics, the quality assessment method based on the weighted entropy of interested region has been proposed, which has better single-peak and sensitivity over the traditional method. Finally, in order to obtain the optimal value of tube voltage and current, the traditional climbing method is improved and the automatic extremum searching algorithm has been put forward in the dissertation.