Design And Implementation Of Image Processing Module For High Accuracy Large Format Scanner

Due to small size, low price, high resolution, large format scanners based on contact image sensor(CIS) became one of the solutions for large format scanning. Research of domestic scanner for this type is to begin from the last ten years, the foundation is weak, it results localization process developmental delay in large format scanner. Due to constrain of image scanning speed, image processing accuracy and etc., domestic high accuracy large format scanner systems are still in initial stage. It is image processing technology research focuses that how to accelerate the massive image data processing speed and improve the image color correction accuracy. In this dissertation key image processing technology is researched, and design and implementation of massive image data splicing, calibration, processing scheduling and display are proposed. The main researches are as follows.(1) The system design of large format scannerSystem framework for large format scanner system was analyzed, the system is divided into different modules, it includes component modules, control modules and PC software module, and brief design of each module is proposed.(2) The fast splicing of massive image dataThrough the source and type of image splicing error analysis, image fast splicing program is designed and implemented. During this process memory consumption is stable, time-consuming is short splicing error control in less than one pixel, which reaches high accuracy and fast splicing requirement.(3) The color correction of CIS imageImage-forming mechanism is studied and rapid exposure programs and multi-point regional calibration algorithm is presented. The experimental results have indicated that the image’s uniformity has been significant promotion and about eight times promotion than before correction and about two times promotion than two-point correction method, which meets the design requirements of high precision.(4) The scheduling of image processing and fast display of massive image dataBased on image block zoning method, the parallel scheduling program of image acquisition, processing and storage and large data images fast display is achieved. During this process memory consumption is stable, and data processing speed is fast, which enhances the efficiency of the scanner.By studying the above key image processing techniques, we proposed a series of image processing solutions for large data, put the techniques apply to large format scanner, improved the image processing speed and accuracy and can also be applied to other massive data processing, such as military reconnaissance, geographic information systems, etc.. In this dissertation large format scanner was constituted by five A4 format CIS, and the massive image data was processed, as far as I know, this is the first report in China.