Patent ID: 8670166

Claim:
A method of automatic white balance adjustment for a scanner, comprising: using a light source to provide a white light to make the scanner scan a document and get an initial image of the document; getting red, green and blue chromatic values of a background color in the initial image; calculating a factor based on the chromatic values and a calibration value which is stored in a calibration sheet; and automatically adjusting a brightness ratio of the red, green and blue lights of the light source according to the factor, and then rescanning the document to get a final image which has a processed background color; wherein the factor is calculated by a formula shown as follows: weighting=WhiteCalibrationSheetLevel/UserBackgroundLevel, where weighting is the factor, WhiteCalibrationSheetLevel is the calibration value in the calibration sheet, and UserBackgroundLevel is the chromatic values can be eliminated of the background color in the initial image.