lyon@zeppy.Sun.COM (Lional Kendall) (11/30/89)
Graphics Wizards: I am looking for software that will convert grey scale pictures (.tiff) from my HP Scanjet back to their original colors. My scanner is presently connected to a 286AT, but I can connect it to my Sun 386i if necessary. Thanks, Lional Kendall SSD Systems Administrator Sun Microsystems, Inc. Mt. View, Ca. 94043 E-Mail: lyon@sun
mjones@stdc01.UUCP (Michael Jones) (12/01/89)
In article <128585@sun.Eng.Sun.COM> lyon@zeppy.Sun.COM (Lional Kendall) writes: > I am looking for software that will convert grey scale pictures (.tiff) > from my HP Scanjet back to their original colors. > My scanner is presently connected to a 286AT, but I can connect it to > my Sun 386i if necessary. I think that this is an honest question, so here is an honest answer: 1. You can't. The color information has been lost. Each monochrome pixel value has been calculated by the scanner as M = .30*R + .59*G + .11*B where R, G, and B are the "colors" in the original. (The scanner may not use the NTSC primaries, but this is the general scheme.) After this, you no longer know, when given M, what the R, G, and B values are. Perhaps Green was more, and Red was less ... or, else Green and Red were less, but Blue was much more, etc. Imagine a guessing game where player A (the scanner) says: "I have a number whose square is 4. Guess it!" and Player B (the person who wants the color back) says "sqrt(4.0) -> 2.0 ... I guess two!". You may be suprised when player A sounds the jarring buzzer and shouts "NO! WRONG! The answer was negative two". The needed information was lost in the squaring, just as it is in scanning. 2. You might. But not in an automated, magic, manner. If you know what colors (pixel chromaticities) were in your original image, then you will be able to supply the information that the scanner lost. If you think you know (i.e. are willing to guess), then you should talk to someone in the "Movie Colorization" industry. Suitable examples would be Color Systems Technologies, American Film Technologies, Colorization, Tintoretto, and Spectral Effects. I can steer you to the best technology for this task if you want to do it, but you really should try solution number three if you have access to the original color material. 3. You can. Buy a color scanner. Several are available, ranging from the basic Mitsubishi SC-7500 (which is sitting beside me now), to the very high quality scanners made by scitex and other prepress groups. You might check out "Array Technologies" -- -- Michael T. Jones Email: ...!{uunet,mcnc}!rti!stdc01!mjones -- -- The wise man will pursue Paper: 3101-H Aileen Drive, Raleigh NC 27606 -- -- excellence in all things Voice: W:(919)361-3800 and H:(919)851-7979 --