Design And Implementation Of Large Format Multi-CCD Scanner Image Processing Module

Due to the application of large format scanners in increasing numbers ofprofessional fields, there have been more and more demands on scanning speed andaccuracy of these scanners, which makes the research and development of a newgeneration of large format scanners more realistically significant.The large format scanner described in this paper adopts the multi-CCD architectureand uses the high-performance scanner controller GL847. The whole scanner system isdivided into three layers, which includes the top-layer device driver, the middle-layerembedded control system and the bottom-layer hardware. This paper mainly introducesthe analysis and design of the top-layer device driver and emphasizes on the design andimplementation of its image processing module. Firstly, software requirements,functional modules division and interface design are presented. Then, a detaileddescription on the design and implementation of the view-display area of the softwareinterface is given. Secondly, there leads to the image processing module followed bynoise generated in the process of imaging, digitizing and transmitting, and thenintroduces the function division and workflow of the module. Finally, the paperdiscusses the design and implementation of each sub-function of the image processingmodule in detail, mainly including piece processing for multi-CCD images, descreenprocessing for scanning printed images, sharpen processing used for imageenhancement and solution to the horizontal stripes problem.Through later online debugging, the feasibility and effectiveness of the top-layerdevice driver are verified. Besides, the scanning speed and image quality of this type ofscanner is greatly improved with the cooperation of the three layers, and the expectedeffect is achieved.