Good day Everyone.

Beginner here.

I took a Screen Print (ie pressing the Print Screen button) and pasted it into GIMP 2.10.32 (rev 1) as a new image. The size of the screen print is 6646 x 1080 pixels as I have 4 monitors.

I then used the crop tool to crop part of the image (1170 x 705 pixels). I did a few tweaks with the paint brush then saved as xcf.

I then opened up G'MIC-Qt by pressing the Filters menu item, then choosing Q'MIC-Qt...

A new window opens up with the Q'MIC-Qt options and stuff HOWEVER the left hand side of the window where the preview image is shows the entire uncropped image instead of the cropped image.

Thinking that maybe Q'MIC-Qt is working with the clipboard image and not the cropped image I took a different screen print and pasted that as a new image in GIMP, then selected the image and then open up Q'MIC-Qt again however it did not show the new screen print but the old one instead so it's not working from the clipboard.
I restarted the PC and loaded up the saved cropped image then selected Q'MIC again and still the large uncropped screen print shows up. I am confused!

Any idea how to get Q'MIC-Qt to work with the actual cropped image?

Thanks

Gimp 2.10.32 - it doesn't delete information from the channel:
viewtopic.php?f=28&t=20006&p=274745#p274745

Enable the 'delete cropped pixels' option in the crop tool options

Hi Rich2005.
This does not explain the Gimp's (2.8 vs. 2.10) other behavior when deleting (Ctrl+X) image selection (with alpha channel).

Just answering the OP's question. Big screenshot - cropped - some edit and saved as a Gimp .xcf.

Gimp .xcf saves all the information including those cropped pixels. In Gimp 2.8 delete cropped pixels toggle was not required as there was no View -> Show All toggle either.

The OP could also have lost the excess with a Image -> Layer to Image Size

When it comes to cutting (Ctrl-X) an image and leaving transparency, up to the user to export with Save color values from transparent pixels on or off. AFAIK no difference between 2.8 and 2.10 Easily demonstrated using the erase tool anti-erase to recover deleted pixels. As here on or off



However, it is a gmic peculiarity that sometimes alpha is ignored. Why, I do know.

I too have noticed this. You may need to ask the creator of GMIC plugin himself. Try here https://discuss.pixls.us/c/software/gmic/10

Thank you so much for your information.

Got it done.

On a side note, does anybody recommend good tutorials for a beginner?

Thanks
StG

Avoid the over-long, over-hyped, verbose youtube videos. 5 minutes is generally enought.

Start off with some text information. https://www.mora-foto.it/en/tutorials-g ... rials.html

There is a easy explanation. G'MIC has no concept of color space. That means coders has to decide whether to take into account of the existence of alpha channel when developing filters, and that makes it very easy for coders to ignore considering alpha. As a G'MIC filter developer, there really should be more notices that other prospective G'MIC filter developers to develop on programs which always input RGBA into G'MIC GUI because most softwares that support G'MIC always has an alpha channel on a image.

Personally, I make G'MIC filters within Paint.NET and on the code[local/global/full], it confirms RGBA input, and I always have a policy to try to take into account of input being one of the following format: RGBA, RGB, GrayA,Gray.

Yeah, this happens to me as well,
I use quite a lot the Rendering or Sequences/3D things from G'MIC, when this happens for example I deleted something on the layer=transparency, then I open G'MIC and see that G'MIC did not take in count the transparent area (or poorly), I close G'MIC, then with GIMP I export as png, then put back the png as new layer and open G'MIC again, then usually it's fine = it's working
I think this started around G'MIC 2.9.x