INPUT IMAGE DEVICE PROVIDING BACKGROUND DETECTION ARRANGEMENT
Original Publication Date: 1990-Dec-31
Included in the Prior Art Database: 2004-Apr-05
Xerox Disclosure Journal
In the reproduction of copies of an original from video image data created, for example, by electronic input scanning from an original document, it is often desirable to provide features dependent on determining the exterior edges of the document. Such features include, for example, automatic magnification, automatic two-up copying, background deletion to avoid storing a document requiring more space than necessary, etc. In the analogous field of light lens copying this has commonly been done by providing a background, against which the document is viewed, that has a tendency to be distinguishable from the image. Thus, for example, backgrounds have been provided with a yellow color, with a black color, with a white color with a whiter than white color, and various other alternatives. All these alternatives work to some extent, but each suffers from the problem that for some documents the background is not well distinguishable from the sheet edge. Thus, black edges of a sheet cannot be distinguished against a black background, canary paper may not be distinguishable against a yellow background, white paper on a white background is questionably detectable, etc.