The Design Of PAL-XGA Image Conversion Controller Based On FPGA

With the development of science and technology, various video display modules show themselves. The compatibility among them is an important problem. However, due to the more and more important role that video products play in our daily life, the video conversion equipment has a larger market. Under this background, this paper focuses on the compatibility of TV signals and computer signals, and designs an image conversion controller.This paper is on the conversion of the digital image in PAL format to the signals that satisfy the XGA standard. After D/A conversion the digital signals can be displayed on the computer screen according to VGA port. Firstly, this paper introduces the principles of video display, including the TV display and computer display, followed with the description of different formats, e.g. PAL, NTSC and XGA display standard. Then the related knowledge about image structure conversion and corresponding realization methods are introduced and we also give the concrete realization methods, such as, the interpolation method for image size conversion, realization method for the frame rate conversion, and conversion scheme from interlaced scanning to non-interlaced scanning, etc. Research and comparison among these methods are performed and the design scheme is proposed.This paper mainly introduced the design process of the image conversion system and the establishment of each module with their algorithms. The whole system is divided into main control module, double RAM module, double FIFO module, image structure rebuilding module and color space conversion module. The whole design plan of the system is shown firstly. The function and structure of the main modules are explained with text illustration. The detailed design scheme, the port diagram and inner configuration of each module as well as the truth tables of some modules are also shown, which describes the whole system in detail and intuitionally. This thesis prsents the specific selected chips as well as the configuration circuits of FPGA, and the scheme of the hardware design for the FPGA based controller is also given.In the final part of this paper, we program each individual module with VHDL language, and debug on the QUARTUS-II software separately. The simulation results which testify that each module can realize its function accurately are given. Then we program and simulate the whole design with the results that have been analyzed to be satisfied with time order of XGA, and prove that the design is rational and realizable with those results.