Research And Implementation Of Key System Based On FPGA

With the developments of broadcast and television manufacture technology, the program quality that audience request become more and more high, the traditional mode that builds the real-life scenery to carry on the photography not only to cost the massive time and the energy, but also can't satisfy the production request much of time, therefore the Virtual Studio technology appear and is applied more and more widely in the recent years. As the core of Virtual studio, key technology is hot pot of the research.In this article the digital key system based on FPGA (Field Programmable Gate Array) is discussed which was studied and implemented by the author. This established to be able effectively to dig out and synthesis stable software and hardware environment, and has applied in the actual project. This research both have throe and reality means.First, one kind of double foreground matting technology is proposed based on analyses of tradition matting technology. This technology can be used to dug out the foreground from the free color background, which transparency objects dug out the picture can be solved perfectly.Then, the digital television signal quantification standard is analyzed, base on traditional key modulation existence problem is pointed out. The method to improve the operational formula has made. Two levels of mapping way are proposed to enhance the processing speed and the precision.After that, the issue, which should be solved in the picture additive process, is discussed in detail. On the base of analyzing digital television signal data construction, TBC (Time Base Correct) processes is put forward to apply in each group signal. Effective data taken off from the key signal is also solved. And the choice and insertion is used to protect assistant data.Finally, the digital keyed system structure is introduced, as well as the key control system working mode. This system is designed and put into effect. The system is proved to be standard for digital television by experiment test and analysis.