Auto-crop after custom rotation

Ideas for improvements and requests for new features in XnView Classic

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fede
Posts: 4
Joined: Sun Sep 16, 2007 10:05 pm

Auto-crop after custom rotation

Post by fede »

Hi all, thank you very much for xn-view, the best freeware (and better than many payware) image viewer :D
I have a small suggestion for us non-pro photographers...I often have to rotate a photo because it's about 1 or less degree askew...it would be very useful to include an option, when you rotate the picture, to automatically crop it to get rid of background border, like it does PSP 8 when you straight a picture. Don't you think so? I thought that "Automatic cropping" does it, but it doesn't work...

Bye
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xnview
Author of XnView
Posts: 36798
Joined: Mon Oct 13, 2003 7:31 am
Location: France

Re: Auto-crop after custom rotation

Post by xnview »

fede wrote:Hi all, thank you very much for xn-view, the best freeware (and better than many payware) image viewer :D
I have a small suggestion for us non-pro photographers...I often have to rotate a photo because it's about 1 or less degree askew...it would be very useful to include an option, when you rotate the picture, to automatically crop it to get rid of background border, like it does PSP 8 when you straight a picture. Don't you think so? I thought that "Automatic cropping" does it, but it doesn't work...

Bye
But when you rotate a picture, there is no background border to crop?
Pierre.
fede
Posts: 4
Joined: Sun Sep 16, 2007 10:05 pm

Re: Auto-crop after custom rotation

Post by fede »

xnview wrote:But when you rotate a picture, there is no background border to crop?
Hi Mr. Developer,
when you custom rotate a picture (let's say, 2 degrees counterwise) four triangles of background color are added to the image to make it rectangular (if you try it by yourself, you'll see...my english is so poor! :wink: ). A lot of graphic programs then added an option to automatically crop the resulting picture to avoid these 4 triangles...

Maybe these pictures will clarify...

Original
Image

Rotated
Image

This is the minimum crop needed to avoid generated background
Image

Then cropped
Image

Bye, and thanks!

PS As I say, this is the most common way to straighten a picture that is a little askew...you'll lose some pixel on the border when you crop, but it's often a lot more important that vertical lines (like buildings) are really vertical and horizontal ones (like horizon) are really horizontal 8)
fede
Posts: 4
Joined: Sun Sep 16, 2007 10:05 pm

Post by fede »

I saw you added this feature to last version of Xnview...thank you!
I suggest to all who will use this feature to enable showing of the grid, since you will be able to use the grid as reference for horizontal and vertical lines in your pictures...

Thanks again!
bye, Fede.
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helmut
Posts: 8240
Joined: Sun Oct 12, 2003 6:47 pm
Location: Frankfurt, Germany

Post by helmut »

Yes, it's very good to see auto-crop during rotation implemented. :-) It's one of various good suggestions in the area "rotation" made in topic Rotation based on the horizon line +auto-crop option.

Darkening auto-cropped area
Rather than auto-cropping the preview immediately it might be even better to just darken the "background" area that will be cropped. That way the user can see and decide, how much of the image is cropped and whether important parts of the image are "lost".

Perhaps showing/hiding the grid in the rotate dialog comes next? ;-)
fede
Posts: 4
Joined: Sun Sep 16, 2007 10:05 pm

Post by fede »

helmut wrote:Darkening auto-cropped area
Rather than auto-cropping the preview immediately it might be even better to just darken the "background" area that will be cropped. That way the user can see and decide, how much of the image is cropped and whether important parts of the image are "lost".
Mmmm...I think you cannot decide when an horizontal line is really...horizontal :wink:
So auto-crop now works as it should be...cropping the less possible part while being straight.

Yes, a straight line that helps you to trace the horizon and make it horizontal (like Paint Shop Pro > 8 do) would be perfect, but also now it works very good.

Just an humble opinion, of course.