Optical Projection System Based On The Defocus Depth Adjustment Methods And Experimental Research

Auto-focus is one of the key technologies in computer vision, imaging system and all kinds of rigid apparatuses.As the utilization of digital imaging apparatus, the research on auto-focus was focused on digital image processing and there were many achievements on this field. Projection display technology has been growing up rapidly in the 1990's. This display technology integrates microelectronics, precision optical instrumentation and precision mechanical technology, and is becoming one of the main stream in the present display field. As one of optical imaging system, the projecting system must involve focus. In this paper, the traits of digital image processing and optical projecting system are gathered. Analysis the auto-focus of projecting system based on DFD(Depth From Defocus) academically and practically.At first, the principal of optical projecting system, auto-focus of digital imaging system and the researching status is introduced. There are mainly two algorithms about digital auto-focus: Depth from focus and Depth from defocus.Then analyzed the optical characters of optical projecting system. Aimed at the traits of optical projecting system, one model of auto-focus of optical projecting system was proposed based on digital image processing technology and computer controlling, also the computing principals and equations were analyzed.After the analysis of the auto-focus model, an experimenting hardware system composed of wide LCD screen projecting system and net-computers was built. Also a software system built on Visual C++ was used to analyze the result of focus of the optical projecting system and to realize the auto-focus of optical projecting system..The theories of digital image processing involved in the processing system were introduced in detail next. Including the image obtaining, image analyzation, image processing and the principals of the image processing software dealing with result feedback.At last, analyzed the value of DFD, prospected the optimization of the DFDalgorithm, discussed the auto-focus digital projecting system on the aspects of hardware and software. Finally, summed up the work having been done and expecting the foreground of application of auto-focus technology.