How to level a curved horizon

[Dil]

Hi, 

 

Newbie here. My first post.

 

I created this image by stitching a series of images using Hugin. As you can see, the horizon is curved (in a slight bowl shape). How can I straighten it? The other Horizon straightening discussions, including the ones on BoltBait's plugin, seem to talk about how to straighten a horizon that tilts, but is otherwise not curved. Thank you.

 

[Red ochre]

Welcome to the forum Dil!

You could use a plugin called Gridwarp - found here.
- set it to use a 2 by 2 grid size and move the middle nub upwards.

[AndrewDavid]

Hi @Dil

Another option is Image Distortion found here https://forums.getpaint.net/topic/114600-image-distortion/

Try these settings. Hope this helps

 

[Pixey]

Here is one especially for a horizon: 

 

[Dil]

I am a bit worried about downloading plugins, etc which were created years ago. The basic operating system and security software have developed many generations during this time. I am afraid that installing an old plug might compromise my system to any security attacks. Any views?

[Dil]

@AndrewDavid, I downloaded the file and got a zip file, but there is no obvious way to run it. Am I missing something?

[ardneh]

Info on how to install plugins:
https://www.getpaint.net/doc/latest/InstallPlugins.html
========================================
One way to correct the curvature:

Add a New Layer.
Adjust an Elliptical selection so that the bottom of
the selection matches the curvature of the water.
fill the selection, deselect, fill the top part.
Expand the canvas to double the height with top anchored.
Apply Boltbait's Flip Vertical plugin, merge layers.

 

Apply Madjik's Gravity plugin.
Crop to selection.

 

 

[Dil]

@ardneh, thank you. I managed to correct the distortion to a reasonable extent using Pyrochild's plugin suggested by @Red ochre. However, I would like to try your method. But I don't know how to draw an elliptical selection that matches the water line!!

[ardneh]

After making a selection using the Ellipse Select tool, the Move Selection tool

can be used on the selection nubs to adjust the selection size / shape.

Holding down the right mouse button will let you rotate the selection.

https://www.getpaint.net/doc/latest/MoveTools.html

 

[Pixey]

11 hours ago, Dil said:

I am a bit worried about downloading plugins, etc which were created years ago. The basic operating system and security software have developed many generations during this time. I am afraid that installing an old plug might compromise my system to any security attacks. Any views?

 

There is no worry to download plugins that were created long ago, as the developers update them periodically to keep up with the newer versions of paint.net.

 

11 hours ago, Dil said:

@AndrewDavid, I downloaded the file and got a zip file, but there is no obvious way to run it. Am I missing something?

 

After you download a Zip file, you must un-zip it and then move the .dll ito the Paint.net Effects Folder on your computer.

 

In the case of Image Distortion, this would be how to use it:

 

    < Clickable >

And the result would have to be cropped to size afterwards:

 

    < Clickable >

 

[Dil]

Thank you, everyone, for your patience and teaching.

[Dil]

I am again trying to correct the curvature of another photo - pretty similar to the previous one. I used the Image Distortion and it worked pretty well.

I wish someone made a tool specifically for this. I guess this kind of stitching of landscape photos must be encountered pretty often and such a tool would be immensely helpful.