This solution is already done in Photoshop:
- I set result image specific size.
- Select crop area (in this case crop area rectangle have a proportional resizing ratio to result image size).
- Make crop and get result image with specific size.
This is useful to create, for example, thumbnails with manual selected area by single operation.
Now i try do same in Gimp. Is that possible with single operation?
Crop and scale are very different things, it appears unlikely to get them both in one single operation.
Nevertheless it is not needed to use a calculator for getting a desired aspect ratio of a (crop) selection in Gimp. We can define this ratio on making our crop or crop selection by just using any values we like. If for example the desired image format should be 200 x 170 pixels wide, just type in these values in the corresponding box:
We can now drag or move this box in any direction or change its size but the ratio will remain 200:170. Before exporting we just scale the image to the desired 200 x 170 pixels:
If we want to crop the image to exact 200 x 170 without scaling later we need to tell it in the dropdown menu next to the input box to not only use a fixed ration but also a fixed size.