- From: Glenn Randers-Pehrson <glennrp@home.com>
- Date: Thu, 04 Oct 2001 12:14:04 -0400
- To: www-patentpolicy-comment@w3.org
Chris Lilley wrote: >Cool. I assume that this is the Dec 1991 reease of NetPBM, so the code >dates from at the latest, 1 December 1991 which is five months before >the patent application on 8 May 1992. Since NetPBM was extremely widely >announced and deployed, and has freely available source, it is a good >prior art claim. Yes, pnmarith is in the 1991 release. >Could you post a command line that takes A.ppm, does channel by channel >composition using channels from B.ppm and composites the result over >C.ppm? Where A, B and C are any rgb ppm images. OK but you'll need to hold me harmless for infringement of the Apple patent. I grant everyone a royalty-free license to use this script for research purposes only. I make no guarantee that using this script will not violate third-party intellectual property claims or that the script is suitable for its intended use. This license expires 11 October 2001. #!/bin/sh # 3-way blending with separate alpha channel per color # (infringes on Apple patent 5379129) # Copyright 2001, Glenn Randers-Pehrson, all rights reserved. # Usage: blend3 width height alpha.ppm file1.ppm file2.ppm # blended file is on standard output pnmmake "#ffffff" width height > ffffff.ppm pnmarith -mult $3 $4 > alpha-times-alpha.ppm pnmarith -subtract ffffff.ppm $3 > 1-minus-alpha.ppm pnmarith -mult 1-minus-alpha.ppm $5 > alpha-minus-1-times-b.ppm pnmarith -add alpha-times-alpha.ppm alpha-minus-1-times-b.ppm rm alpha-times-alpha.ppm 1-minus-alpha.ppm alpha-minus-1-times-b.ppm rm ffffff.ppm Glenn
Received on Thursday, 4 October 2001 12:16:49 UTC