1 hour ago
(This post was last modified: 1 hour ago by makeitwork101.)
I understand that this an old thread, but I too noticed the blurring/degradation of sharp edges when using the rotate tool in GIMP 2, which wasn't an issue in prior versions when rotating a layer by 90° or 180°.
I've just started using GIMP 3, and was hoping that the issue would be resolved, but it hasn't.
Although it makes sense that, due to interpolation, degradation of square pixels is to be expected when rotating by angles other than 90° or 180°, it doesn't make sense that an older version of GIMP would be better at rotating squares than a newer version. To my knowledge GIMP has yet to provide a satisfactory solution, but if all you want is a simple 90° or 180° rotation, I have a clunky workaround.
It's been a while since I've used Windows but, like Linux, I'm sure it has a basic "Image Viewer" and I'm sure that viewer has a rotate option. When I want to rotate an image by 90° or 180°, I open it with system's viewer, rotate it and close the viewer. The viewer then asks me if I want to "save changes to image" and I select "save."
The image is then saved, at the new angle, and I see zero degradation of the sharp edges made of square pixels... see attached images.
It's far from perfect, and again, it only works when rotating by 90° or 180°, but I hope it helps.
I've just started using GIMP 3, and was hoping that the issue would be resolved, but it hasn't.
Although it makes sense that, due to interpolation, degradation of square pixels is to be expected when rotating by angles other than 90° or 180°, it doesn't make sense that an older version of GIMP would be better at rotating squares than a newer version. To my knowledge GIMP has yet to provide a satisfactory solution, but if all you want is a simple 90° or 180° rotation, I have a clunky workaround.
It's been a while since I've used Windows but, like Linux, I'm sure it has a basic "Image Viewer" and I'm sure that viewer has a rotate option. When I want to rotate an image by 90° or 180°, I open it with system's viewer, rotate it and close the viewer. The viewer then asks me if I want to "save changes to image" and I select "save."
The image is then saved, at the new angle, and I see zero degradation of the sharp edges made of square pixels... see attached images.
It's far from perfect, and again, it only works when rotating by 90° or 180°, but I hope it helps.