63fb46d6_bster_US___Patent_applications__Description
[Patent application number] 20090185228 [Published] 07-23-2009 [Description] 
REAL-TIME PROCESSING OF GRAYSCALE IMAGE DATA - In a digital reproduction system incorporating a single pass scanner, accurate image processing results from processing a subset of grayscale image data. More specifically, scanlines that correspond to the leading edge of a document are stored and processed to detect skew and to obtain an appropriate correction. The lead edge correction is then applied to the entire grayscale image. Accordingly, the present systems and methods eliminate skew from grayscale images in real-time. The corrected image is rendered to binary and stored in electronic pre-collation memory and cropping, masking and other image editing operations can be performed on the binary image data before the image is printed.
Xing Li, Webster US - Patent applications