Rotate without blurring edges

[EmilHarold]

I've got a png with nice edges.

When I try to rotate the image (Image -> Free Rotate) the edges blur towards white.

Is there a way to prevent this edge effect?

[migf1]

Hi emil,

it is always best to rotate just once (each intermediate rotation till the final result adds distortion, so the more the rotations the more the accumulated distortion).

If you know exactly how many degrees you want to rotate, type them in the Free input-field of the Free Rotate dialog. The image dimensions also play a role in how much distortion can be accumulated before it becomes an issue visually (the bigger the dimensions, the more tolerance to accumulated distortion before it becomes an issue). Mirroring/flipping either vertically or horizontally should not introduce any distortion.

Now, if you don't know before hand how much rotation you want to apply, it is probably easier to use the Pick tool and start experimenting till you get the desired angle. When you rotate with the PIck tool, the horizontal Tool Options toolbar at the top, shows (among other things) the final rotation angle. So when you have the final rotation, keep a note of the angle, Undo till you get back to where you started from, then open the Image -> Free Rotation dialog and type-in manually the value of the angle.

You can also type the value in the Angle field directly on the toolbar, but the rotations with the Pick tool alter other settings too (position, perspective, even scale). Moreover, if you type-in the final angle directly on the toolbar, it will most probably change your pivot point too. So instead of trying to remember all those, just use the Free Rotation dialog and punch in just the degrees.

[LeviFiction]

I would like to note that the Pick tool can rotate without accumulated distortion as long as you don't do something else between rotations. The second you apply the change or move away from the tool the edit becomes permanent and destructive. Same with scaling.

So if you do nothing but rotate the layer with the pick tool and never deselect it, never go to a different tool, the pick tool will rotate without the distortion if multiple rotations.

You can also avoid having to Undo all of your rotations by rotating a duplicate layer as a test and then deleting that layer once you know how much rotation you need.

[migf1]

Oh, I was not aware of that! That's really awesome! Thank you very much Levi!

But I have a question: I do not see any "apply" or check-mark button on the toolbar. So, the only way to Apply the final transformation is to move away of the layer or the pick tool?

[JoeB]

Unless I learned something incorrectly a long time ago, if you rotate any image other than a vector image in any amount except 90 degrees you are going to get some blurring along edges, particularly noticeable along straight edges. I certainly stand to be corrected.

[migf1]

Unless I learned something incorrectly a long time ago, if you rotate any image other than a vector image in any amount except 90 degrees you are going to get some blurring along edges, particularly noticeable along straight edges. I certainly stand to be corrected.

Yes, transformations on raster layers are destructive (except for flipping/mirroring). The bigger the image the better, but they are destructive anyway. In all programs, not just in PSP.

However, what Levi suggested was about finalizing the transformation. For example, in Ps when you enter the Transformation mode (Ctrl+T) you can experiment with as many transformations you want, and they won't get applied until you hit the Enter key. This way, no matter how many steps you experimented with while in Transform mode, Ps applies only the final result (that is, it transforms the layer just once).

Until yesterday, I was under the impression that PSP did not have such a feature. Put otherwise, I thought that every experimental step while transforming with the Pick tool was final. Levi suggested that it is not, and that PSP's way to finalize the transformation is to move away of the Pick tool or switch to a different layer, etc (that is, instead of Ps way to hit the Enter key). Tbh, I am not sure it works, but I'll keep it in mind the next time I will need to transform a raster layer and see if it really works.

[JoeB]

Understood. I was just posting for the sake of the original poster, who was asking how to rotate without blurring the edges, not about when the Pick tool sets the transformation. I felt he/she should know that it can't be done except in 90 degree rotations. But I agree it's also good to know when and how the Pick tool works when doing rotations because I wasn't aware of it either.

[Jean-Luc]

I've got a png with nice edges.

What is the size of your image in pixel?
What is the zoom value before to make your screen capture?