Tom Poe wrote:

I scanned in a sketch that is displayed as a black and white sketch. I now want to replace the black with blue color. Then, I will have a blue and white sketch. Does that make sense? Is there a command, or feature on Gimp that lets me do that?

That is a fairly common operation. What you want is a colour map. Right click->Filters->Colors->Map->Color Exchange

Then select your black and blue as the colours to be exchanged (which you obviously knew).

Harish

Tom Poe wrote:

Harish: Thank you very much for the help. I created a .png file of a sketch, scanned into computer, brought it up in Gimp. Tried the color exchange on the image by selecting all, then filter->color->map->color exchange. Didn't work, so I tried creating a new file and adding the sketch as a paste in a new layer, selecting all and trying the color exchange, but no go. If I send you the file, could you check on your computer and see if it works for you?

Sure.

But before that, by "didn't work", do you mean the operation wasn't allowed (the menu option was greyed out) or the operation failed to do what you wanted?

If the menu option was greyed out, it is because your scanner's png is in 'indexed' mode. Follow
Right Click->Image->Mode-RGB to switch the image type to RGB and retry the operation. If it still doesn't work, e-mail it to me (off list), and I'll take a look.

Harish

Can you use the color picker for this? On 1/15/06, Harish Narayanan wrote:

Tom Poe wrote:

Harish: Thank you very much for the help. I created a .png file of a sketch, scanned into computer, brought it up in Gimp. Tried the color exchange on the image by selecting all, then filter->color->map->color exchange. Didn't work, so I tried creating a new file and adding the sketch as a paste in a new layer, selecting all and trying the color exchange, but no go. If I send you the file, could you check on your computer and see if it works for you?

Sure.

But before that, by "didn't work", do you mean the operation wasn't allowed (the menu option was greyed out) or the operation failed to do what you wanted?

If the menu option was greyed out, it is because your scanner's png is in 'indexed' mode. Follow
Right Click->Image->Mode-RGB to switch the image type to RGB and retry the operation. If it still doesn't work, e-mail it to me (off list), and I'll take a look.

Harish

I have changed Black & White images to Blue & White by using: Tools->Color Tools->Color Balance
and then increasing Blue and, if necessary, decreasing red (increasing cyan). I would then optionally use Tools->Color Tools->Brightness-Contrast and adjust brightness.

On Saturday 14 January 2006 21:55, Tom Poe wrote:

I scanned in a sketch that is displayed as a black and white sketch. I now want to replace the black with blue color. Then, I will have a blue and white sketch. Does that make sense? Is there a command, or feature on Gimp that lets me do that?
Thanks,
Tom