The Design And Implementation Of CCD Image Acquisition Software System

The Multi-CCD scanners which are widely used in printing, scientific research,medical and other fields have important applications in optical-electronic-machineryintegration equipment. At present, with the rapid development a lot of industries need toarchive large format materials. Therefore, the demand for large-format scanner isincreasing, while promoting the development and production of large format scanners.The main work of the large-format scanner is to convert the analog signal to the digitalsignal which the computer can identify after converting the image’s optical signal to theanalog signal. In order to scan large format images, an effective approach is to captureimages through multiple sensors, then splice the image to complete the large-formatscanner’s work. The scanner use four same type CCD to capture the images then splicethem into one. While the four CCDs scan asynchronously to accomplish thephotoelectric conversion in the process.The main work of this paper can be divided into two parts, hardware and softwaredesign. The first part is the hardware work, after analyzing the large format scanner’sworking principle and hardware system’s performance parameters the developmentcontent and focuses of the work of large-format scanner has been determined. Thedevices have been selected according to the parameters. Then we finished the scannerhardware circuit design and FPGA’s timing design including the driver andconfiguration of the digital-to-analog conversion chip. This is the important factor to theimage quality. Converting the optical signal to the analog signal laid a foundation toenhance image quality which is the key to large-format scanning. The second part isabout the upper software system development. About this the paper introduced thedemand, the division of the functional modules of the software and the three-tierstructure of the large-format scanner software system firstly. Then the paper detailed thescanning interface design and implementation, focused on the design ideas of themulti-threaded parallel data acquisition and memory management strategy to deal withthe large amount of image data. This content is directly related to the focus of the userapplication experience of the large-format scanner, also is the the focal point to the implement.Final, the test of the system’s hardware and software. The test results show that thedesign achieved the acquistion function and good performance. At the same time, thesystem achieved the expected acquisition speed and quality of the collected image.