How can I redraw a line in the diagram

[andreas5gfrei]

Hello
I am a Gimp beginner, although I have already mastered the basics.

Attached are two graphics: One shows a diagram in black and white. I need a revision, as shown in the other image: the diagram in red, the rest remains black.

The red line should remain as thin as possible and be smoothed, not like in my example with these outliers.

Since I have to revise a lot of these charts like this, I'm looking for a very quick solution so I don't have to spend a lot of time on this.

Thanks for any good tips.

Greetings
Andreas

[Ofnuts]

Are they supposed to be the same size (because these are not). And if I put them to sale they look about identical.

   

[andreas5gfrei]

yes, they should be same size and should be "identical":
except, that the result of the work should be, that the graph is red, not the circles, not the grate.

[Ofnuts]

(12-29-2022, 09:43 AM)andreas5gfrei Wrote: yes, they should be same size and should be "identical":
except, that the result of the work should be, that the graph is red, not the circles, not the grate.

So how is this different from the first one (bar the 10/20/30dB lines)?

[denzjos]

So I tried:
Make a copy layer
Make a path from the dB lines
Stroke the path with white
Copy the left side of the drawing to a new layer, flip it horizontal and drag it in place
Do the same with part of the upper side of the drawing and flip it vertical
Optimise the rest (two vertical lines in the center)
Make a new layer and stroke the path with red
   

  dB path.xcf (Size: 83.78 KB / Downloads: 90)

[andreas5gfrei]

[quote pid='32644' dateline='1672313049']
hot to
Make a path from the dB lines
??
with magnetic scissors







[/quote]

[rich2005]

Another way. I wish I had a shortcut method for you. Because of the image this is very hands-on You will be hard pressed for a quick solution.

In the video: https://youtu.be/vcLgq7cP3K8  3 minutes

1. Duplicate layer
2. Fuzzy select the line, threshold 120 to 130 (add any little bits missing as well)
3. Grow the selection by 1 pixel
4. Colors -> Map -> Color Exchange black to red and up the 3 sliders to maximaum
5. Repair the lettering using the clone tool, alignment = registered and clone from bottomlayer to top.





   

( curses, missed a bit )

[andreas5gfrei]

(12-29-2022, 12:54 PM)andreas5gfrei Wrote: [quote pid='32644' dateline='1672313049']
Hi rich2005
thank you very much for this excellent solution and tutorial.

Now I can do this within a minute.


Res

[/quote]