Thresholder for text and photographs
CA 1182554 A · Owner: International Business Machines Corporation · Inventors: Fox, Sidney J.; Zimmermann, William J. Jr.; Yeskel, Filip J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An image processing apparatus and method adapted for use with a bilevel printer to reproduce mixed format documents including text and photographs. The image processing apparatus includes an input buffer means for storing pixels. For each pixel of interest a, gradient signal of surrounding pixels is generated. A plurality of reflectance signals representative of the characteristics of pixels downstream from the pixel of interest is determined. A plurality of machine state signals representative of desired reflectance characteristics of a document are stored. A controller correlates the state signals the, reflectance signals and the gradient signals to select an optimum thresholder for …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted February 12, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 12, 2002.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.