Rotation based on the horizon line +auto-crop option

[Olivier_G]

For leveling a photography, I would like to be able to draw a line (+adjust its ends) directly on the image to actually show where the horizon is. The program would then rotate the image to get this line horizontal: it would be very accurate... in one single step.

An option "auto-crop (with same ratio)" in the tool would automatically crop the picture to maximize the area inside the borders, with the same ratio as the original image.

This tool would be very easy to use and efficient to level & crop photos... (my dad confirmed... )

Olivier

[Mpemba]

For leveling a photography, I would like to be able to draw a line (+adjust its ends) directly on the image to actually show where the horizon is. The program would then rotate the image to get this line horizontal: it would be very accurate... in one single step.

Olivier

This feature would be very useful.

I could not do without it in PhotoShop.

M

[helmut]

Another two excellent suggestion, Olivier!

- Horizontal alignment
As a start, it would be helpful if there was a checkbox to show/hide a grid in the rotate dialog. With enabled grid, adjusting vertical / horizontal alignment would be much easier.
Sure enough, your suggestion for horizontal alignment is much easier to handle and sophisticated.

- Auto-crop
If I understand right, your "Auto-crop with ratio" is the existing auto-crop with the extra that ratio is kept.
At the moment, auto-crop does not work very well for me. Perhaps it's me using auto-cropping in a wrong way or for the wrong pictures. In which context / for what kind of photos would you use that?

[Olivier_G]

Another two excellent suggestion, Olivier!

Thank you Helmut...

- Auto-crop
If I understand right, your "Auto-crop with ratio" is the existing auto-crop with the extra that ratio is kept.

No, it is not an add-on of the current "auto-crop" feature.

It would be a feature of this new Level/Rotate tool: once you rotate an image, you usually want to crop it while keeping the same ratio -> there is only 1 best solution to do this (and it is based on geometry, rather than 'guessing' as in the normal 'auto-crop' tool).

This being said, this "ratio" feature could also be added to the current "auto-crop" tool...

Olivier

[helmut]

An option "auto-crop (with same ratio)" in the tool would automatically crop the picture to maximize the area inside the borders, with the same ratio as the original image.

With your explanation and re-reading your initial text I understand what you mean and strongly support this: Why should the user be forced to cut off the areas of the image which has become invalid due to the rotation? The program should be really smart enough to do that - even more accurate than the user.

The auto-crop should be clearly become an option of the "Rotate" dialog.

There's the "Rotate by drawing line" and the "Rotate" dialog. I think they are both related and should interact somehow. Perhaps the user first draws the line and when confirming rotation, the rotate dialog is opened.

[FlorianH]

I think it's a very good idea and support it. Should make it in the next release (after 1.82 ). Rotating big images is some kind of (time consuming) try and error game for me with the current version of XnView.

[Olivier_G]

Perhaps the user first draws the line and when confirming rotation, the rotate dialog is opened.

I would actually prefer the other way:
- select: Rotate>Custom
- draw a line (move the dialog if needed) to get real-time angle measurement ['apply to image' immediately unchecked]
- apply to image to check the result and start over again or adjust precisely if you are not happy
=> You do it all with that rotate dialog (line, apply/check, modify...).

Olivier
PS: and auto-crop should be added too...

[Georg]

I'm supporting this suggestion I'd like all four pieces in my workflow: the "horizon-line-drawing" makes XnView automatically set the rotate-value, thanks to shown grid (ticked checkbox) I can see whether auto did it all right (and if not I just finetune the degree manually), ticking "auto-crop" checkbox, clicking on "rotate" and everything is done. Very handy indeed.