Image rotation - newbie question

[tonmilx]

I am new to GIMP but have worked out how to do most of what I need to do. Using v2.10 on OSX (Mavericks).

Using Tools/Transform/Rotate.

The menu appears and I can rotate by degrees by dragging the slider or using the Angle.
But everything I have seen on other posts suggests I should see the actual image itself rotate.

What I actually see is an outline of the image rotate - but it doesn't show me the picture rotating within it. i.e.., its difficult to see how much rotation I want when I can't see the image itself rotating.

When I press the ROTATE button, the orientation remains as it was but the image has rotated within it (hope this makes sense)


I am stupid I know - but it can't be that hard to rotate an image by degrees and see the results of the rotation on the image before I accept it...


I found this video: https://youtu.be/_-kkXAiKmKo

Its windows I know, but I don't see that behaviour.

If I use Image/Transform/Rotate then I only get the 90 degree presets

Please help a newbie...

[rich2005]

First of all, an image will always be rectangular with vertical and horizontal sides. You can not have one leaning at an angle. That is the way raster (bitmap) graphics work.

The video is for Gimp 2.8. Gimp 2.10 has a slightly different interface and most probably a very dark (default) theme. Otherwise exactly the same.

There are ways of changing the theme but sticking to rotating.

Using the rotate tool , check the Interpolation (1) Clipping set to adjust (2) and if you want guides set them (3)

Click in the canvas to free-rotate (4) or use the slider. Whole angles use the dialogue (5) If you need to detach that little entry box use that upward arrow (6)

   

Click on rotate and that gets this:

   

The yellow dotted line is now the layer boundary (7). Increase the canvas size to fit Image -> Fit Canvas to Layers (8)

Which gives this:

   

Save as a Gimp xcf if you intend more editing. Export as a .png image to keep the transparency for printing / web use etc.

This will be the same for Windows / OSX / linux

[gstalnaker]

Rich2005 - excellent tutorial. Is there anyway to make that grid overlay NOT rotate with the image. I've always found it odd that it does. I'd prefer to use the grid as the orientation for how much rotation I want (e.g., aligning vertical surfaces -- makes sense to me that this would be easier if the grid did not rotate). Now I have to remember to pull manual grid lines into the image before rotation.

[Blighty]

(12-20-2018, 05:43 AM)gstalnaker Wrote: Is there anyway to make that grid overlay NOT rotate with the image.

1) Select the Rotate tool
2) In the tool options, check Corrective (Backward)

Now the grid rotates; you can align the grid with features in your image.

[rich2005]

Quote:...Now I have to remember to pull manual grid lines into the image before rotation

Using guides is a really good habit to get into, however there is also the built-in grid, View -> Show Grid If using a lot, set up a keyboard shortcut. I wonder how many users bother to set it up globally for their particular use Edit -> Preferences -> Default Image -> Default Grid This can be adjusted on an image-by-image basis Image -> Configure Grid the settings are saved with the image in .xcf format.

Gimp 2.10 has additional tools. The measure tool now straightens. Follow a vertical (or horizontal) surface, click on straighten.

[gstalnaker]

(12-20-2018, 09:16 AM)rich2005 Wrote:

Quote:...Now I have to remember to pull manual grid lines into the image before rotation

Using guides is a really good habit to get into, however there is also the built-in grid, View -> Show Grid If using a lot, set up a keyboard shortcut. I wonder how many users bother to set it up globally for their particular use Edit -> Preferences -> Default Image -> Default Grid This can be adjusted on an image-by-image basis Image -> Configure Grid the settings are saved with the image in .xcf format.

Gimp 2.10 has additional tools. The measure tool now straightens. Follow a vertical (or horizontal) surface, click on straighten.

rich2005 - much thanks! Exactly the kind of option I'd expect to be on the Rotate command (since that command, well, rotates an image). I'd never (and did not ever) think to look for it on the Measure command. But thanks to you now I know.

[gstalnaker]

(12-20-2018, 07:57 AM)Blighty Wrote:

(12-20-2018, 05:43 AM)gstalnaker Wrote: Is there anyway to make that grid overlay NOT rotate with the image.

1) Select the Rotate tool
2) In the tool options, check Corrective (Backward)

Now the grid rotates; you can align the grid with features in your image.

Blighty! And this is also excellent because now, using your comments and a bit of exploration, I understand the Rotate command's options and how they work. And I'm a dope for not exploring them before now (talk about RTFM!).

[pexaj]

(12-16-2018, 10:33 AM)tonmilx Wrote: I am new to GIMP but have worked out how to do most of what I need to do. Using v2.10 on OSX (Mavericks).

Using Tools/Transform/Rotate.

The menu appears and I can rotate by degrees by dragging the slider or using the Angle.
But everything I have seen on other posts suggests I should see the actual image itself rotate.

What I actually see is an outline of the image rotate is there any Free online video rotating tool- but it doesn't show me the picture rotating within it. i.e.., its difficult to see how much rotation I want when I can't see the image itself rotating.

When I press the ROTATE button, the orientation remains as it was but the image has rotated within it (hope this makes sense)


I am stupid I know - but it can't be that hard to rotate an image by degrees and see the results of the rotation on the image before I accept it...


I found this video: https://youtu.be/_-kkXAiKmKo

Its windows I know, but I don't see that behaviour.

If I use Image/Transform/Rotate then I only get the 90 degree presets

Please help a newbie...

Hello. When I import a photo and it needs to be rotated 90 degrees how do I do it without going through the very cumbersome menu rotation which is in 15-degree increments? Can't believe there is not a one-step 90-degree rotation possible.

[rich2005]

Quote: Can't believe there is not a one-step 90-degree rotation possible.

Try  Already mentioned but not one step

Layer -> Transform and either Rotate 90 ⁰ clockwise or Rotate 90 ⁰ counter-clockwise.  

But you can set up a keyboard shortcut.

[sallyanne]

Someone may have already mentioned it already. but what you are looking for is -the grid doesn't move. Guides do! Especially those put in at the tool options.