Scanning bi-tonal images Bi-tonal images are scanned images that are made up of only black- and-white elements. The descriptions below are for bi-tonal images only.

Binarization is the process of converting a grayscale or color image to a bi-tonal image. There are several different methods of performing this conversion. Two of the options Kodak provides are iThresholding and Adaptive Threshold Processing.

These options are applied to grayscale scanned images and output a bi-tonal electronic image. Thresholding and Adaptive Threshold Processing separate the foreground information from the background information even when the background color or shading varies, and the foreground information varies in color quality and darkness. Different types of documents may be scanned using the same image processing parameters and still result in excellent scanned images.

•iThresholding: selecting iThresholding allows the scanner to dynamically evaluate each document to determine the optimal threshold value to produce the highest quality image. This allows scanning of mixed document sets with varying quality (i.e., faint text, shaded backgrounds, color backgrounds) to be scanned using a single setting thus reducing the need for document sorting.

When using iThresholding, only Contrast may be adjusted.

•Adaptive Thresholding (ATP): the Adaptive Threshold Processor separates the foreground information in an image (i.e., text, graphics, lines, etc.) from the background information (i.e., white or non-white paper background).

When using Adaptive Thresholding, Threshold and Contrast may be adjusted.

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A-61527 May 2006