Aces High Bulletin Board

General Forums => The O' Club => Topic started by: Scherf on June 13, 2011, 04:05:30 AM

Title: Can computer software "attribute" colours to B&W?
Post by: Scherf on June 13, 2011, 04:05:30 AM
Got a black and white shot of a crashed Mossie - roundels, squadron markings and fin flash are all visible, so can tell the software what's red, what's blue, what's yellow, what's grey and, since it's on a grassy field, what's brown/black and what's green.

Can software attribute the rest?
Title: Re: Can computer software "attribute" colours to B&W?
Post by: gyrene81 on June 13, 2011, 08:37:33 AM
oooh, good question...very interesting idea.

did a search and found some interesting tidbits of info...evidently it's a grayscale to rgb filter process.

http://www.google.com/search?hl=en&lr=&q=Convert+GRAYSCALE+to+COLOR&btnG=Google+Search (http://www.google.com/search?hl=en&lr=&q=Convert+GRAYSCALE+to+COLOR&btnG=Google+Search)


this one may be a down and dirty way to do it...
http://lists.xcf.berkeley.edu/lists/gimp-user/2000-March/000961.html (http://lists.xcf.berkeley.edu/lists/gimp-user/2000-March/000961.html)
Quote
If you've got one of the newer 1.1.x versions of Gimp you already have
the software.
Here is a quickie intro to how its done.

First you'll need your greyscale image and another image that you're
going to get colors from. 

Convert the greyscale image to RGB

Select an area from the color image, this will be the source for the
color in your colorized image.

Now right mouse click on the image to be colorized and select Filters >
Colors > Map > Sample Colorize.

You'll get a dialogue window where you can select the source and target
and adjust colors and stuff.  When the preview looks like it might work
click Apply and be amazed as your image is colorized.

This filter is a LOT of fun and I think you'll be surprised by the
results. If you do a good job of selecting the source colors you can get
some incredible results. 
Title: Re: Can computer software "attribute" colours to B&W?
Post by: Scherf on June 13, 2011, 08:49:44 AM
Thanks for that. It:s all about seeing whether, given a bunch of other colour parameters, the computer thinks a specific area is grey or brown...
Title: Re: Can computer software "attribute" colours to B&W?
Post by: Bino on June 13, 2011, 08:58:00 AM
Just remember that the original image might have some odd characteristics.  For example, there was a B&W film used in the 1940's - called orthographic, if I recall right - that rendered the bright yellow poison gas detector patches on RAF fighters' wings as a very dark grey.