Patent ID: 8526077

Claim:
A scanning system having a brightness compensation mechanism for compensating brightness when the scanning system scans a plurality of pages, the scanning system comprising: a light source, for generating a brightness to illuminate the pages; an image sensor, for sensing image data shown on the pages in order to output analog signal data corresponding to the image data; an analog-front-end control unit, for controlling a gain value and an offset value of digital signal data in an analog-front-end; and an image processing apparatus, comprising: an image processing module, for receiving digital signal data which are converted format of analog image data; a statistic window control unit coupled to the image processing module, for establishing a statistic window setting region wherein the statistic window setting region serves as a reference region of brightness statistic data associated with each of the pages; a brightness statistic logic unit coupled to statistic window control unit, for generating current brightness statistic data of a current page based on the statistic window setting region; and a comparison logic unit coupled to the brightness statistic logic unit, for comparing the brightness statistic data with a brightness target value to determine whether the brightness statistic data is the same as the brightness target value for adjusting the brightness of the scanning system according to the compared result between the brightness statistic data and the brightness target value, wherein when the current brightness statistic data is different from the brightness target value, the image processing apparatus utilizes an adjusting signal based on a brightness difference between the current brightness statistic data and the brightness target value for compensating the brightness of the light source, wherein when the current brightness statistic data is different from the brightness target value the analog-front-end control unit utilizes the adjusting signal based on a brightness difference between the current brightness statistic data and the brightness target value for adjusting the gain value of the analog-front-end (AFE) in the scanning system.