User`s guide

January 2008 15
IMAGE PROCESSING FEATURES
Advanced image processing capabilities have long been the hallmark of document image
scanners. The i780 Scanner advances image processing to a new level, taking all the best and
adding more. Full-speed image processing in color, grayscale and black and white arenas in a
scanner of this capability offers an unparalleled opportunity for today’s demanding document
management systems. The table below outlines the image processing features available for
color/grayscale and black and white images. Remember that the i780 Scanner processes images
at full rated speed.
Feature Color
Black and
White
Grayscale
Adaptive Threshold Processing X
Auto Color Detection X X
Brightness and Contrast Control X
Four cropping options X X X
Deskew X X X
Electronic Color Dropout X
Fixed Thresholding X
Halftone Removal X
Polarity X
Noise Filter X
Orthogonal Rotation X X X
Auto Orientation/Auto Rotation X X X
Perfect Page with iThresholding X
Adaptive Threshold Processing
After skew correction and auto-cropping algorithms have been applied to the scanned image, the
grayscale image is processed using Adaptive Threshold Processor (ATP) which is built into the
scanner software. ATP turns a grayscale image into a black and white image. The ATP algorithms
utilize a two-dimensional symmetrical array of surrounding pixels in order to accurately determine
the value of each pixel. Other approaches use only a few surrounding pixels to make the
determination.