replace color of pixels of one color in a specific area???

[TMORT]

I have an image that is from a picture of a drawing. It is all one layer.  I would like to change certain specific colored pixels in specific areas from their current color to another. I know I can do this for the entire image.

In this case it is text and the current color is black which is present in other parts of the drawing and it is on a background color that is also in other parts of the drawing.

Something like a brush or eraser set so when it passes over an area would change just any black pixels to red might be best for this situation.


A rectangle or free select might work too, but  in this case maybe a brush type thing seems like it would be easier.

It sort of sounds like the magic wand tool, but that is different and pretty unpredictable as well.

[rich2005]

(05-23-2023, 02:02 PM)TMORT Wrote: I have an image that is from a picture of a drawing. It is all one layer.  I would like to change certain specific colored pixels in specific areas from their current color to another. I know I can do this for the entire image.

In this case it is text and the current color is black which is present in other parts of the drawing and it is on a background color that is also in other parts of the drawing.

Something like a brush or eraser set so when it passes over an area would change just any black pixels to red might be best for this situation.

I can not think of a really good way, apart from identifying the font and typing over existing. All depends on the background to the text.

There is a brush mode Color Erase which does what it says but is also liable to change the underlying colours.

Quote:A rectangle or free select might work too, but  in this case maybe a brush type thing seems like it would be easier.

It sort of sounds like the magic wand tool, but that is different and pretty unpredictable as well.

Maybe a combination of selection tools

1. Isolate the text with (say) Rectangular select tool.
2. Use the Colour select tool in Intersect mode with increased threshold value to select the text.
3. Colour Fill the selection

40 second demo of that: https://i.imgur.com/nUI0g65.mp4

[TMORT]

I think I'll just erase the text, grab the background color and refill the now transparent area with the old color and then add new text.

It is a GeoTiff image and I found that GIMP saves the georeferences, and I am working with the image after it has been warped.

So that is my plan. It may take me a while to get to it though.

Maybe this will be a chance to learn the text tool well too. I've used it, but I do struggle with setting the size, color and what not. I can get it to work eventually, but usually there is quite a struggle.