Post Reply 

global color change

Nov 18, 2018, 16:05 (This post was last modified: Nov 18, 2018 16:09 by Whburling.)
Post: #1
global color change
I am creating test images for an electronic sign.

The image was created in GIMP 2.10.8 and was declared an RGB image
before anything was drawn.

It consists of 24 pairs of rows, one pixel in height and 112 pixels long. Each pair consists of a black row and a color row.

How to make a single test pattern and then change the color of the color row with a simple step(s) to make multiple test images.

I created the original image using a white background upon which I drew black foreground lines with a pencil..

When sent to the LED sign, the test image should turn on, in the vertical dimension only, every other pixel so that Red and Green and Blue LEDs produce white if the pixel is on. Otherwise the pixel is off.

Now i would like to create another test pattern replacing white with some other color.

I could select each white row and change its color using a bucket fill, but there must be a better way that reduces making all those selections. Since I am using only the foreground color and background color I thought maybe I could change the background color and all the spatial regions that were the original background color would automatically change. However that did not work.

In looking around it seems some people use "color to alpha plugin".
The only problem is I can not find such a plugin....not even a grayed out plugin.

So FIRST....Am i pursuing the most appropriate method of changing the white background (that is how the white originally was formed) to another color by using the color to alpha plugin. IF not please offer an alternative approach.

if so, please help me gain access to the color to alpha plugin. As mentioned earlier, I declared the image mode as RGB before I drew a single line.

One last request....It would be nice if I could reverse the black lines and make them white lines and repeat the above changes. That would enable me to test the pixels are not tested in the above test pattern. I also would like to change the horizontal lines to vertical lines. Perhaps there is an easy way to do that.

Keep in mind, I am trying to learn GIMP so I am willing to invest the time to learn the technique which I can use in the future for more complex images.

Thank you for any input you can offer me.

Find all posts by this user
Quote this message in a reply
Nov 18, 2018, 21:49
Post: #2
RE: global color change
This forum is had been DEAD for a long time.

The spammers keep trying to take over.

Save yourself from them and go to instead
Find all posts by this user
Quote this message in a reply
Post Reply 

Possibly Related Threads...
Thread: Author Replies: Views: Last Post
  Multi-Frame Color Change DarwinsFLinch 2 72 Apr 16, 2019 19:15
Last Post: DarwinsFLinch
  How to sweep an area with a color kkawabat 1 70 Apr 5, 2019 08:14
Last Post: paynekj
  Change the colour of the water Hymer 1 77 Mar 28, 2019 14:34
Last Post: paynekj
  How To Change PDF Pages To Suit Printout? abrogard 0 120 Mar 23, 2019 00:48
Last Post: abrogard
  How do I change font of placed text? JeffCyr 1 122 Mar 20, 2019 09:18
Last Post: paynekj

Forum Jump:

GIMP ForumPortalArchiveContactTermsRSS