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+--- Thread: Working with layers - a headstart of a beginner... (/Thread-Working-with-layers-a-headstart-of-a-beginner)
Working with layers - a headstart of a beginner... - saint_m - 04-10-2026
good day dear experts, hello everyone,
i am currenty workin on some preliminary steps for a new project.
i want to show a little image for illustration. Therefore i need a image with some dots.
I have a basic-image (which i want to use as a starting point.)
well -i need only the dots - that are blue - not the green ones and not the yellow ones.
how to achive this:
well i think that i can work here with layers - or "masks" : can ´t i?
that saidL i think that we re able to - let us say "to isolate a certain amount oif the dots"
So - if i could work with layers - then i would be able to achive a image where i only have a certain amound of dots left - the (above menitoned) blue ones
How would you do that: - how would you try to achieve that - to make sure that only this blue dots remain.
so the question is: – how would you approach this, what's the best way to proceed? Should I use layers or masks?
I think it should be possible to isolate a single color here – to focus on the dots with only one certain color - the blue oner: , so to speak – and extract them - so that those dots are what remains in the end.
Should I do this with layers (or layers) or masks?
[attachment=14360]
i think that this is a gerneral Beginner question - and yes: if i can do this - if i achive this - then i guess that i would be able to lots of other things more with GIMP
Loook forward to hear from you
greetings
RE: Working with layers - a headstart of a beginner... - denzjos - 04-10-2026
Use the 'Select by Colour Tool', set Threshold 25, set the 'Select by Colour' mode to add (second icon from the left below the tekst 'Select by Colour) and click on a few blue dots (dark blue, light blue,... what you want). Then 'Select / Grow' set 2 pixels and copy the result to a new layer and make a new white layer (or the colour you like) below the 'dots' layer.
[attachment=14361]
RE: Working with layers - a headstart of a beginner... - saint_m - 04-10-2026
hello dear Denzjos
many thanks for the quick reply and for the input - awesome - and a great asset of GIMP-knowledge for me. I am delighted. Your image - it shows great great achivements.
as i understand that - i can use "Color-Tool"
and within that - i can set the threshold - to a "certain value"
BTW: you
firstly: took the Threshold 25, and afterwards you set the 'Select by Colour' mode to add (second icon from the left below the tekst 'Select by Colour)
and afterwards - you
second: click on a few blue dots (dark blue, light blue,...) and then
thirds: 'Select / Grow' set 2 pixels and copy the result to a new layer and make a new white layer (or the colour you like) below the 'dots' layer.
thank you so much. I will try out these steps at the weekend.
you saved my day.
have a great day. - greetings.
Saint_M
BTW: you earned 10 stars out of 5 possible..
ps and update:
btw:
according to this thread here - https://www.gimp-forum.net/Thread-color-scala-how-to-define-the-colors-right-with-a-real-example
here a additional question: how to apply the LCH-Ideas to the above mentioned image - how to proceed!?
cf : see the link here to the according description: https://www.prasannamestha.com/blog/science-of-beautiful-color-gradients
you recommended me this - in the above mentioned thread.
the so called: LCH Color Mode
Quote:LCH stands for Lightness, Chroma and Hue. It is pretty similar to HSL but is modelled after human vision. Oftentimes, it is referred to as HCL color mode.
HCL or LCH - however you may want to call it, provides a consistent lightness of colors as perceived by human eyes. I prefer this color mode as it enables us to generate gradients with consistent lightness. Here’s an example:
well - could i apply this to the dots-collection in the image:;
well i guess that we need to work here -with two different layers/( or masks)?
How - and that is the question - how would you do this!?
on which way and method would you apply the scale of various colors to the above mentioned image - with the dots.
Can we apply the gradient with some kind of increasing "behaviour" or "manner"!?
intended Structure: from Left (cold colors) to right (warm and hot colors of the LCH-Gradiend...
Look forward to hear from you
greetings.