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The acquisition and processing of image signal are used widely in the fields of scientific research, industrial and agricultural production, medicine and sanitation, public security and so on. Meanwhile image acquisition is the basis of image processing, compressing and recognizing, so the research on image acquisition system is very important and valuable.The research of“Design of Image Acquisition System of Digital Microscope”is to design an image acquisition system of digital microscope. The system integrated modern image acquisition technology into traditional microscope, and incorporates microscope system, CCD vidicon, image acquisition card, device driver, application of windows OS and other main function module. In the research, the hardware circuit of the system was designed and PCB board was produced. The software of the card which incorporated device driver and application of windows OS was developed too.Philips SAA7134 PCI video decoder was adopted in the image acquisition card. The card incorporates ADC, video decoder and scaling control, supports all TV standard, PCI 2.2 compliant including full ACPI, configurable PCI FIFOs and Virtual-to-physical address conversion by the MMU.For the driver design, the architecture of AVStream minidriver, the structure of device descriptor, the processing paradigms, the allocating and maintaining of frames queue were deeply analyzed. Furthermore, the development of driver of image acquisition card was introduced, which include implements of PnP dispatch table, video capture filter, video capture pin, scatter/gather DMA transform, crossbar filter, installation of driver, debug of driver and so on.For the application design, the architecture and technology of DirectShow was introduced in detail. The main functions of application were implemented which include the creating of video capture filter graph, the stream control, the control of image quality, video preview and video capture.
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