Patent ID: 7187808

Claim:
A method to enhance a digital image quality wherein original brightness data Xij of a concerned pixel is compared with predetermined brightness levels X 1 and X 2 , which are reference variables to obtain new brightness data Yij, with an enhanced contrast, the method comprising: setting initial values of a parameter V b to calculate the brightness level X 1 , a parameter V P to calculate the brightness level X 2 , the brightness level X 1 , and the brightness level X 2 ; comparing the brightness data Xij with the parameters V b and V p , respectively, and outputting results indicative thereof; resetting the parameters V b and V p according to the results of the comparison; identifying a background area according to the results of the comparison between the brightness data Xij and parameter X 1 or X 2 ; performing the contrast enhancement on pixels belonging to the background area; and updating the brightness levels X 1 and X 2 using the parameters V b and V p , respectively, when the concerned pixel is the last one in the concerned line, wherein the comparison of the brightness data Xij with the parameters V b and V p is performed until one of the concerned pixel is the last one and the concerned pixel is the last pixel to be subject to the contrast enhancement.