Distortion and Mesh Warp

Here everybody can post his problems with PhotoLine
MikeFromMesa
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Distortion and Mesh Warp

Post by MikeFromMesa » Sun 13 May 2018 23:46

I ran into a couple of issues with an image today when trying to fix the perspective of a fish-eye image. I wanted to make two adjustments - to stretch the image vertically and to use what I think of as Mesh Warp (what PhotoLine refers to as vector points) to correct some distortion in the image interior. I have not run into this before because I have not been using the fish-eye as it is a new lens for me.

My first step was to correct the internal distortion by "pulling" down the interior of the image to correct some objects that appeared to be too high. Of course that worked properly, but when I next tried to stretch the entire top to compensate for the vertical fish-eye compression I ran into the issue of the original vector point, and it only allowed me adjust in relation to the vector point I had created. That is, the vector point I entered to correct the internal distortion created an anchor and I could not find any way to force PL to incorporate that adjustment and allow me to proceed with the entire remaining image.

To work around this issue I decided to reverse the order of adjustments and do the "stretch" first. I went back to the initial image and tried to "pull" the entire top of the image to do the stretch, but it would not allow me to do that. It would pull the center, or I could pull both corners and try to make the distances the same, but surely there is some way to stretch an entire side of the image without having to stretch the corners. Pulling at the center of the top generated a curved extension, and did not stretch the entire top. I was again able to work-around this issue by stretching both corners and assuming the amounts were the same, and then the internal Mesh Warp adjustment worked properly, but I assume I am missing something to have to do these individual adjustments.

So I have two questions. First, if I do a vector point to adjust the interior of an image, how do I tell PL to keep the adjustment and still allow me to do further vector point adjustments without reference to the point I created? Second, how do I stretch one entire side of an image without having to stretch two corners and hope I have stretched them the same amount?

Thank you for any help.

Martin Huber
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Re: Distortion and Mesh Warp

Post by Martin Huber » Wed 16 May 2018 12:04

MikeFromMesa wrote:
Sun 13 May 2018 23:46
I ran into a couple of issues with an image today when trying to fix the perspective of a fish-eye image. I wanted to make two adjustments - to stretch the image vertically and to use what I think of as Mesh Warp (what PhotoLine refers to as vector points) (...)
You mean the Distort tool?
MikeFromMesa wrote:
Sun 13 May 2018 23:46
So I have two questions. First, if I do a vector point to adjust the interior of an image, how do I tell PL to keep the adjustment and still allow me to do further vector point adjustments without reference to the point I created?
I don't understand exactly what you are doing. A small sample document might be helpful.
MikeFromMesa wrote:
Sun 13 May 2018 23:46
Second, how do I stretch one entire side of an image without having to stretch two corners and hope I have stretched them the same amount?
You can select and edit several at once. Modifier keys (Shift, Alt, Command/Ctrl) are usually helpful, too.

Martin

MikeFromMesa
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Re: Distortion and Mesh Warp

Post by MikeFromMesa » Thu 17 May 2018 15:33

Martin Huber wrote:
Wed 16 May 2018 12:04
You mean the Distort tool?
Yes.
Martin Huber wrote:
Wed 16 May 2018 12:04
I don't understand exactly what you are doing. A small sample document might be helpful.
I am trying to drag an entire side of an image, in this case the top, to stretch the image in the vertical direction. I want to stretch the entire top of the image, not just the point I have selected.

I have been using a fish-eye lens to capture ultra-wide images instead of taking multiple images and stitching them together with pano software. I then "de-fish" the image using the distortion correction functionality of my workflow tool (Dxo's PhotoLab), and that gives me a more or less rectilinear image, but the image seems to be compressed vertically. That is, structures like natural arches (Arches National Park in Utah, USA) and natural bridges (Natural Bridges National Monument in Utah, USA) are not as high, relative to their width, as they should be, so I want to stretch the image to restore the horizontal to vertical proportions.

However when I select part of the top of the image in PhotoLine and drag it I end up pulling only part of the image, not the entire top, so that creates a bulge at the point where I am dragging it. I want to drag the entire top (or side, or bottom). If this is not clear I can create a screen capture and show you what happens when I do this with PhotoLine.
Martin Huber wrote:
Wed 16 May 2018 12:04
You can select and edit several at once. Modifier keys (Shift, Alt, Command/Ctrl) are usually helpful, too.
I tried doing this, but it did not give me the ability to drag the entire top of the image.

Martin Huber
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Re: Distortion and Mesh Warp

Post by Martin Huber » Fri 18 May 2018 09:09

MikeFromMesa wrote:
Thu 17 May 2018 15:33
I tried doing this, but it did not give me the ability to drag the entire top of the image.
You can select several knots/points, but can't move the selected points together?

Martin

MikeFromMesa
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Re: Distortion and Mesh Warp

Post by MikeFromMesa » Fri 18 May 2018 15:24

Martin Huber wrote:
Fri 18 May 2018 09:09
You can select several knots/points, but can't move the selected points together?
When I use the Cmd key and click on a "node", it activates. When I then do the same on a second node the first one deactivates, so I can not seem to get two "nodes" activated at the same time. When I use the Alt key I get the same result.

Dragging from the center of the image only gives me a "hump" expansion, not the entire top. Here is a screen recording showing what I did. I end up having to drag both sides and then trust that I have them "pulled" the same amount.

https://www.dropbox.com/s/e9z1eouecah1b ... e.mov?dl=0

I assume I am doing something wrong, but I do not know what.

Paul
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Re: Distortion and Mesh Warp

Post by Paul » Fri 18 May 2018 17:04

You should use the shift key to add a point to the selection. Or drag around the points you want to select.
- Paul

MikeFromMesa
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Re: Distortion and Mesh Warp

Post by MikeFromMesa » Sat 19 May 2018 01:57

Oh, the Shift key. I tried the Cmd, Option and Control keys, but not the shift key.

That seems to work. Thank you.