Article View: sci.image.processing
Article #865Question: Converting a Negative to a Positive
From: Local Brian Lee
Date: Mon, 23 Nov 1992 23:22
Date: Mon, 23 Nov 1992 23:22
51 lines
2343 bytes
2343 bytes
-- hello people, I'm not too sure if this is the right place to ask this but if it's not I'm sure s/one will set me straight. This is probably a simple question for all you graphics/imaging gurus out there so I'm expecting a flood of responses: OK: If I have a 35mm negative and I grab that slide onto my PC with some sort of frame grabber then what's involved in turning that image into a positive ? Is it a simple matter of subtracting every pixel from its max value ? e.g. say I have a 24 plane image (i.e. no colour map) to get a positive of a pixel with a value of say 0x123456 is it as simple as doing: 0xffffff - 0x123456 = positive value ? Any comments please ...Thanks...Brian hello people, I'm not too sure if this is the right place to ask this but if it's not I'm sure s/one will set me straight. This is probably a simple question for all you graphics/imaging gurus out there so I'm expecting a flood of responses: OK: If I have a 35mm negative and I grab that slide onto my PC with some sort of frame grabber then what's involved in turning that image into a positive ? Is it a simple matter of subtracting every pixel from its max value ? e.g. say I have a 24 plane image (i.e. no colour map) to get a positive of a pixel with a value of say 0x123456 is it as simple as doing: 0xffffff - 0x123456 = positive value ? Any comments please ...Thanks...Brian ============================================================================== This is my signature file. This file tells people that I don't know anything and that I don't mean to say anything. And that Anything that sounds like I might have said really is just a figment of the readers imagination. =============================================================================
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arc1-ca.pugleaf.net!sparky!uunet!haven.umd.edu!decuac!pa.dec.com!e2big.mko.dec.com!funlwb.stl.dec.com!bribie.sna.dec.com!leeShow Full Headers
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Newsgroups: sci.image.processing Path: arc1-ca.pugleaf.net!sparky!uunet!haven.umd.edu!decuac!pa.dec.com!e2big.mko.dec.com!funlwb.stl.dec.com!bribie.sna.dec.com!lee From: lee@bribie.sna.dec.com (Local Brian Lee) Subject: Question: Converting a Negative to a Positive Message-ID: <1992Nov23.232235.10201@funlwb.enet.dec.com> Lines: 51 Sender: l_lee@bribie.sna.dec.com (Local Brian Lee) Nntp-Posting-Host: bribie.sna.dec.com Reply-To: lee@aussie.enet.dec.com Organization: Digital CSS Sydney Australia Date: Mon, 23 Nov 1992 23:22:35 GMT