Note: this method applies only to bigger images cut out properly (for instance, multiple screenshots of something too big to fit on a screen), not to picture extracts done with a handheld camera/smartphone that are in the realm of panorama software such as Hugin). This method can also give decent results with partial scans, but this assumes that there is very little distortion in the scanner, which isn't always a given.

• You temporarily set the layer at the top to Difference mode. This will show you outlines in both pics where they overlap. Yes, the top layer doesn't show in the areas where there is nothing below it.
  

   

• You move the top layer and and when the position is pixel-perfect the overlap goes completely black. In the last stages you can move the layer pixel-by-pixel using the cursor keys (or you can zoom in to some part of the image with many small details)
  

   

• You set the top layer back to Normal mode to restore the full image.
  

   

• Rinse and repeat for every layer.
  

Hello, I am newbbie, so please excuse my question if it is too stupid!
I have an .png image (white-logo.png), which I want to exploit/project on a bigger background image (04.png).
Not sure if this is possible at all with GiMP.

Thank you in advance for your response!

Best regards,
Lucky

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  Colour change.xcf (Size: 18.88 KB / Downloads: 1057)   If I have a circle filled with red colour with anti-aliasing and feathering turned on, and if I then change the colour to blue, the colour on the edges still remains red. How can I fill the colour perfectly including the anti-aliased and feathered margins?

Hello. I'm running Gimp 2.10 on Linux Mint 20.  I have a standard AFAIK rgb jpg from my android phone.  I am having trouble with the clone tool selecting a source.  I have got it to sometimes, but mostly not.  I don't know what I did to make it work, but it now won't work again.  

I know about holding ctrl to select source, then releasing it. But it's not working and  doesn't leave the source brush behind and sometimes leaves the error message to set a clone source - which disappears at some point (again, I can't make it go, not sure what the trigger is).

I am also having problems with the dodge/burn not toggling too.  
I've used the clone tool loads before with no problems, but I'm an intermittent user but have been for many years.
I also previously installed the resynthesiser plugin - could this be linked?

If anyone could help, I'd appreciate it as I've used up a load of time getting nowhere.
Many thanks

I tried to use the Formula in the manual but the results are similar to when I use Subtract and Addition Modes in Gimp when using MixRGB Nodes in Blender.
 I tried separating the RGB channels and did a straight up calculation on each channel and the results look to washed out. 

I looked in the code at github and is says:

[blendModeKeys.GRAIN_EXTRACT]: (i, m) => (
i - m + 0.5

I attached a pic of the Node Setup and the results and what it should look like.
Anybody know what the problem is?

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Hi, I installed gimp a while ago and sharpened worked for a bit then stopped. Now it doesn't show as highlighted? Or whatever you call it, I try to click it and it doesn't work for me? I operate on Windows 10 Vista. I also put a picture below to show what I mean.

Hello,

I have split an image with guides and now have quite a few images. I would like to export all of them, but then I would have to click on export for each image.

Is there a better way?

Hi all! I'm trying to work out a script that I can use to reduce the size of an image by half. However, I need this to work with images of different sizes, but I always want them to be scaled to half their size. I know that this code exists:

It is sometimes needed to add an object in an image and make it look part of it by appearing behind foreground elements and in front of background elements. With the proper technique this isn't difficult:

• Add the object in a new layer
  
• Duplicate the image layer
  
• Move the copy above the object layer (which is sandwiched between the two images)
  
• Using a layer mask, erase the top image except where it is in the immediate vicinity of the object: you start by removing most of the image (big brush or bucket-fill with a selection), remove most of the rest with a small brush, and shave off the outline where needed with a soft brush.
  
• The only place where erasure should be accurate is where a foreground element intersects the inserted object
  

   

• The layer group is not strictly necessary. It is  used for demo purposes so the group thumbnail shows the effect of the mask
  
• You can see how little of the "copy" you need
  
• The image a good example... cutting out the whole cat properly with all the hairs would have been a daunting task (1600 pixels of fuzziness). But here the only place where we need a sharp cut in on the ears, which are not fuzzy (200 pixels of sharpness), as shown by the red lines below:
  

   

Can one set the aspect ratio toggle switch from the 'Set Image Canvas Size' always 'on'  (locked) ?