Research On Correction Technology Of Large Format Flathed Scanner Based On Gl847Controller

The quality of image scanning (QoIS) which mainly consists of color accuracyand geometry accuracy is an extremely important metric in the performanceevaluations of scanners. The scanners developed by our team are able to meet therequirements such as high resolution and high speed in some special applications.However, they are still not good enough for the applications where high coloraccuracy and high geometry accuracy are demanded.This paper proposes a new method towards the direction of improving the QoISof scanners on the basis of previous works. We first conduct the Black and WhiteField Correction by adjusting the black field offsets and white field target valuesbased on the characteristics of scanned images. With the help of field corrections, weadopt the power function instead of the third-order or fifth-order polynomial functionas the basis function to perform the curve fitting in Gamma Correction. To improvethe geometry accuracy of image scanning, condition variables are used to replace themutex in the thread synchronization procedure.Finally, the results in this paper indicate that our method can greatly enhance theQoIS of the concerned scanner. In particular, it can reduce the aberration and stabilizethe height difference between sub-images in the conjunction area.