| 摘要 |
A method is provided for reducing a background in a raster image as generated from capturing a hardcopy original. The background indicates a deviation between a lightness value of a subset of pixels in the raster image and a maximum lightness value of raster image input values, contrasting with dark information in the image. Two areas around the target pixel are defined, one area being substantially smaller than the other. An average of a lightness value of the pixels in each of the two areas are combined to obtain a background parameter, indicating a locally varying background in the raster image. A target pixel lightness value is scaled using the background parameter and the maximum lightness value. |
