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Expired Canadian patentCanada

Method and apparatus for providing anti-aliased edges in pixel-mapped computer graphics

CA 1250379 A · Owner: Edelson, Steven D. · Inventors: Edelson, Steven D.

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Abstract From the Canadian patent

Smoothing information consisting of a mix value which indicates what percentage of the new color is to be displayed in a given pixel is stored in a pixel-plane memory. The value for the percentage for the old color is derived by subtracting the indicated percentage from 100%. Three methods for encoding the mix value for a pixel are disclosed. The first method allocates specific bits for color and mix values. The second method encodes either mixing or color values in each pixel word. The subsequent pixel word is checked before deciding the proper treatment of a given pixel. The third method encodes either a color value or multiple mix values in each pixel word. The mix information is then …

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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 21, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 21, 2006.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledDecember 13, 1985
GrantedFebruary 21, 1989
Term endedFebruary 21, 2006
Patent numberCA 1250379 A
Classification (IPC)G09G3/00 +2 more

Timeline

Timeline From CIPO dates

1986198919921995199820012004Application filedDec 13, 1985Patent grantedFeb 21, 1989Term endedFeb 21, 2006

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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.