I'm using Mac OS Big Sur and use GIMP 2.10. In spite of all the tutor video's I can't create a background to remove. After selecting Foreground at the end of the process, nothing happens. There appear no lining around the foreground. Does anyone recognise this problem? If yes, can it be solved?

When you have an image that is in indexed color (so it has a palette that contains a set numbers of colors, example 10 colors only).
Then when you bring in an RGB full color image (by pasting it in I guess).
GIMP will turn your your RGB full color image into indexed as well, while trying to match colors of your RGB to indexed as best it can.

What is their formula/algorithm for doing this? I want enough details to replicate GIMP's color-matching functionality.


How can I find it in code in GIMP's source code?

Why do I want to know this?: I want to add a color matching method for my cross-stitching plug-ins called "GIMP's method" instead of Delta-E and Perceptive as these are sometimes off as well...and GIMP's seem to do a great job at keeping the RGB image looking very close with those limited indexed colors.  Just curious to find out if GIMP's method is superior compared to Perceptive and/or Delta-E.

Thank you in advance.

Hello, I didn't find how to cross-link a path. Is it possible in Gimp and how to do it. I need it as i am using the path tool to create something like a map of countries with their borders. Thanks !

Hi, newbie to the forum here.

I wondered if anyone could advise on the following?

I am using artistic effects that apply to the whole layer rather than ones that can be used with a paint tool.

I want to style the artistic effect differently in different parts of the image - for example an artistic effect might have a stroke direction - an 'angle' -
so "on this part of the image strokes should be at 30 degrees and over here strokes should be at 60 degrees".

So the problem is how to vary effects that apply to the whole layer with regional variations by changing a variable or setting supplied in the artistic filter, I am using 'stroke angle' for an example but it could be any variable that can be changed on an artistic effect that is applied to the whole layer. 

The method I have been experimenting with is to make say 5 layers and apply the "whole layer" artistic effect to each layer in turn, each time with a different stroke angle.
So I may have

layer0 - stroke angle of 0 degrees applied to artistic effect
layer1 - stroke angle of 30 degrees applied to artistic effect
layer2 - stroke angle of 60 degrees applied to artistic effect

and so on....

I then added a layer mask to each layer.

This means I can achieve the result I want and I can see the result live in the main layer as I use say the rubber tool to remove areas of layer mask for each layer, if I rub out the layer1 mask at one location I can have a stroke of 30 degrees and then if I rub out the layer2 mask in a different place then I see the 60 degree stroke coming through.

Great it works !!! But.........


The only problem is that for this to work well I need to make sure that my layer masks are mutually exclusive from one another - if I use the rubber tool on one layer mask at position A then I must not use the rubber tool at that same position in any of the other masks otherwise I will not have the desired result that for any pixel the contribution comes from only one of my layers - in my case the layers in question are mode=dodge so I do not get the desired effect if more than one layer is allowed to contribute to any single pixel.

I cannot use modes on the layers themselves to combine them in different ways because they all have to be "dodge".

So it seems that the only way I can get the mutual exclusivity I want is to have some "magic" option that views my five layer masks as being part of a set and if a pixel in any one of these masks is transparent then the same pixels in all the other masks must be opaque - if I use the rubber tool to make a particular pixel transparent then the other layer masks must all react automatically and set that same pixel opaque.

It could be progressive, for instance perhaps the pixel at a particular position in the image might have transparency in the layer masks as follows  0.6, 0.2, 0.1, 0.1, 0.0   - ie adding up to 1.0 at all times - so if I used a rubber tool I might use multiple strokes to progressively make layer 5 dominant in a particular region but always so that the contribution from the other layers is decreased accordingly.   

I can't help thinking it must be a common wish to use an artistic effect that applies to the whole image and to wish to use layers each with the same image but a different setting for the artistic effect and then to want to paint on masks to determine which setting is used in different places on the screen?

Is there any kind of mask that can take say 5 layers as 'input' be painted on freehand with facilities to allow only one layer as output or to blend the contribution from each layer in a sensible way?

Conceptually a mask where each pixel has a value 1 to 5 to indicate layer and so can only accept one layer as input for any particular pixel? -

Or a mask system were five channels are blended according to how I paint on the mask but the result is only a weighted average of the 5 layers, perhaps a system that is progressive so that if I wish to have layer 5 dominate in a particular area then repeated strokes of a tool on the mask in that area will progressively weight more and more to layer 5 with the other other layers diminishing in their input at every stroke?

Its not an easy one to describe

Thanks in advance
Jon

Hi, 

I want to be able to measure the length of a path, but I can't see any way to do this. Ideally I want to be able to split the path up into equal line segments, in order to do this I first need to know how long the path is. Does anyone know how I can easily measure the length of a highly curved path? Bonus points if you also know how to split that path up into equally sized segments! 

I have attached an image of the path so you can see what I am am trying to measure. If you feel I have made anything unclear I am happy to answer any questions to clarify

Thanks in advance

Attached Files

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Hi you all,


Many colleague of mine work with TIFF files, in which (opening them with some apps like Photoshop) you can find several layers (brightness, shades, paints etc.).
How can I open them correctly and save them again with similar information?

I didn't find any working plugin. Even this one https://wiki.panotools.org/Multi-Layer_T...h_the_Gimp does not work with my version (2.10).
What can I do?

Thank you very much in advance

S


-------------- I searched this question through the forum without result - then sorry if I didn't find an already answered topic. Or if the section is wrong!

... Rich2005, who started the first thread that reached 100K views.

Congratulations!

OK I must be the dumbest person on the planet but I've been using photoshop for years and wanted to get off the Adobe train.  I wanted to try Gimp and I can't even change the color of the background.  I created a new "canvas" it was white, I wanted to change the color.  I selected all and went to the color picker, changed color, nothing...I added some text in the canvas.  I believe I have it selected.  Chose a different color, tired both foreground and background.  Nothing.  Wouldn't change.  Please help...

Is it me or are there general internet problems today? I have had problems accessing Reddit, StackOverflow, Gimp.org, and some others. Doesn't look like my own internet (mostly errors from the servers themselves, and doesn't work either on my work PC which  only sees the internet through a heavily filtered VPN...).