Advanced perspective correction tools – distortion tools

On Tue, 2 Feb 2010 08:28:49 -0800 (PST), Paolo wrote:

Hello everybody,
I’ve googled a long time before coming and asking.
I’m considering to buy a graphic/retouching program and I was thinking about photoshop.
Problem is, I often have to correct huge amounts of badly taken photos and I often need to apply massive perspective corrections/distorsions. The Lens Correction tool is ok, but not fast enough (by the time you set the horizontal perspective correctly, the vertical goes all wrong and you have to overshoot the correction on one axis to get it right in a few tries).

I would check out the various modes of the transform tool – there’s more flexibility since you can adjust the numerical values directly, either visually or by typing in the numbers. Preview is also faster than with the lens corr tool.

The best package for correcting distortions is probably PTGui, which costs in the neighborhood of $100 USD. It is intended mainly for panorama and mosaic assembly, and preview is somewhat slow. It should have the capability to do what you need, and produce images at least as good as Photoshop.

I also need to correct both the horizontal and vertical axis, not just one (i.e.: the "horizon line" thingy is totally useless for me). This is my question: is there any way to tell PS (or, FWIW, any other similar program) to distort/adjust as a rectangle a given quadrilateral whose vertices I click-set directly on the image, maybe with a simple average of x and y coordinates – that shouldn’t be so difficult to implement?

AFAIK no one does this, yet. It would be a very fast and effective way to adjust perspective. It is easy to waste a lot of time correcting one thing, only to have it thrown out of kilter by the next adjustment. What I do, sometimes, is to actually draw on a resampled version of the image to get the parameters correct, then re-use the same settings on the full sized version of the image – slow but accurate.
—
Mike Russell – http://www.curvemeister.com

Mike Russell found these unused words:

On Tue, 2 Feb 2010 08:28:49 -0800 (PST), Paolo wrote:

Hello everybody,
I’ve googled a long time before coming and asking.
I’m considering to buy a graphic/retouching program and I was thinking about photoshop.
Problem is, I often have to correct huge amounts of badly taken photos and I often need to apply massive perspective corrections/distorsions. The Lens Correction tool is ok, but not fast enough (by the time you set the horizontal perspective correctly, the vertical goes all wrong and you have to overshoot the correction on one axis to get it right in a few tries).

I would check out the various modes of the transform tool – there’s more flexibility since you can adjust the numerical values directly, either visually or by typing in the numbers. Preview is also faster than with the lens corr tool.

…. and has a perspective mode! A little ‘size’ tweak to adjust for apparent compression in the opposite adjustment [usually vertical].

The best package for correcting distortions is probably PTGui, which costs in the neighborhood of $100 USD. It is intended mainly for panorama and mosaic assembly, and preview is somewhat slow. It should have the capability to do what you need, and produce images at least as good as Photoshop.

I also need to correct both the horizontal and vertical axis, not just one (i.e.: the "horizon line" thingy is totally useless for me). This is my question: is there any way to tell PS (or, FWIW, any other similar program) to distort/adjust as a rectangle a given quadrilateral whose vertices I click-set directly on the image, maybe with a simple average of x and y coordinates – that shouldn’t be so difficult to implement?

AFAIK no one does this, yet. It would be a very fast and effective way to adjust perspective. It is easy to waste a lot of time correcting one thing, only to have it thrown out of kilter by the next adjustment. What I do, sometimes, is to actually draw on a resampled version of the image to get the parameters correct, then re-use the same settings on the full sized version of the image – slow but accurate.

What’s wrong with the Transform => skew?

You can set the h and v values directly, also nullify any increase in size and ‘correct’ any apparent rotation.

On 3 Feb, 01:00, Sir F. A. Rien wrote:

Mike Russell found these unused words:

On Tue, 2 Feb 2010 08:28:49 -0800 (PST), Paolo wrote:

Hello everybody,
I’ve googled a long time before coming and asking.
I’m considering to buy a graphic/retouching program and I was thinking about photoshop.
Problem is, I often have to correct huge amounts of badly taken photos and I often need to apply massive perspective corrections/distorsions. The Lens Correction tool is ok, but not fast enough (by the time you set the horizontal perspective correctly, the vertical goes all wrong and you have to overshoot the correction on one axis to get it right in a few tries).

I would check out the various modes of the transform tool – there’s more flexibility since you can adjust the numerical values directly, either visually or by typing in the numbers.  Preview is also faster than with the lens corr tool.

… and has a perspective mode! A little ‘size’ tweak to adjust for apparent compression in the opposite adjustment [usually vertical].

The best package for correcting distortions is probably PTGui, which costs in the neighborhood of $100 USD.  It is intended mainly for panorama and mosaic assembly, and preview is somewhat slow.  It should have the capability to do what you need, and produce images at least as good as Photoshop.

I also need to correct both the horizontal and vertical axis, not just one (i.e.: the "horizon line" thingy is totally useless for me). This is my question: is there any way to tell PS (or, FWIW, any other similar program) to distort/adjust as a rectangle a given quadrilateral whose vertices I click-set directly on the image, maybe with a simple average of x and y coordinates – that shouldn’t be so difficult to implement?

AFAIK no one does this, yet.  It would be a very fast and effective way to adjust perspective.  It is easy to waste a lot of time correcting one thing, only to have it thrown out of kilter by the next adjustment.  What I do, sometimes, is to actually draw on a resampled version of the image to get the parameters correct, then re-use the same settings on the full sized version of the image – slow but accurate.

What’s wrong with the Transform => skew?

You can set the h and v values directly, also nullify any increase in size and ‘correct’ any apparent rotation.

Nothing really.
Simply that’s much more slow than clicking four ponint and pressing return on the keyboard.
I wouldn’t bother if I were to adjust my photos (I usually make small adjustments only to compensate for a minimal deformation induced by the lenses), but trust me when I say that some of the things I work with are serious mess-ups, and there are lots of ’em.
So, the skew tool is too slow for me, even with a reference grid on the background, and direct value typing doesn’t help me much… What I need (or what I think I need) is something more of a vectorial software feature than a graphics one…

On 3 Feb, 11:03, Paolo wrote:

On 3 Feb, 01:00, Sir F. A. Rien wrote:

Mike Russell found these unused words:

On Tue, 2 Feb 2010 08:28:49 -0800 (PST), Paolo wrote:

Hello everybody,
I’ve googled a long time before coming and asking.
I’m considering to buy a graphic/retouching program and I was thinking about photoshop.
Problem is, I often have to correct huge amounts of badly taken photos and I often need to apply massive perspective corrections/distorsions. The Lens Correction tool is ok, but not fast enough (by the time you set the horizontal perspective correctly, the vertical goes all wrong and you have to overshoot the correction on one axis to get it right in a few tries).

I would check out the various modes of the transform tool – there’s more flexibility since you can adjust the numerical values directly, either visually or by typing in the numbers.  Preview is also faster than with the lens corr tool.

… and has a perspective mode! A little ‘size’ tweak to adjust for apparent compression in the opposite adjustment [usually vertical].

The best package for correcting distortions is probably PTGui, which costs in the neighborhood of $100 USD.  It is intended mainly for panorama and mosaic assembly, and preview is somewhat slow.  It should have the capability to do what you need, and produce images at least as good as Photoshop.

I also need to correct both the horizontal and vertical axis, not just one (i.e.: the "horizon line" thingy is totally useless for me). This is my question: is there any way to tell PS (or, FWIW, any other similar program) to distort/adjust as a rectangle a given quadrilateral whose vertices I click-set directly on the image, maybe with a simple average of x and y coordinates – that shouldn’t be so difficult to implement?

AFAIK no one does this, yet.  It would be a very fast and effective way to adjust perspective.  It is easy to waste a lot of time correcting one thing, only to have it thrown out of kilter by the next adjustment.  What I do, sometimes, is to actually draw on a resampled version of the image to get the parameters correct, then re-use the same settings on the full sized version of the image – slow but accurate.

What’s wrong with the Transform => skew?

You can set the h and v values directly, also nullify any increase in size and ‘correct’ any apparent rotation.

Nothing really.
Simply that’s much more slow than clicking four ponint and pressing return on the keyboard.
I wouldn’t bother if I were to adjust my photos (I usually make small adjustments only to compensate for a minimal deformation induced by the lenses), but trust me when I say that some of the things I work with are serious mess-ups, and there are lots of ’em.
So, the skew tool is too slow for me, even with a reference grid on the background, and direct value typing doesn’t help me much… What I need (or what I think I need) is something more of a vectorial software feature than a graphics one…

Oh, and thanks to all two for the quickness of Your answers. Much appreciated.
P.

In article
,
Paolo wrote:

Problem is, I often have to correct huge amounts of badly taken photos and I often need to apply massive perspective corrections/distorsions.

You have received some good suggestions, so may I ask why you have to correct huge amounts of badly done photos?

As a content editor, I simply reject poor work..

On 3 Feb, 17:43, John Stafford wrote:

In article
,

 Paolo wrote:

Problem is, I often have to correct huge amounts of badly taken photos and I often need to apply massive perspective corrections/distorsions.

You have received some good suggestions, so may I ask why you have to correct huge amounts of badly done photos?

As a content editor, I simply reject poor work..

Because I’m not a content editor? 😉
Jokes aside, I mainly work for amateurs, and they know nothing about photo, but they sure know how to bug the hell out of us at the shop. I appreciated very much all the suggestions that have hereby been given to me, and I’m starting to delve deeper into the matter, trying everything out.
Just wondering why a seemingly simple feature that would do a lot more than some purposeless eye-candy enhancement we once in a while see in graphic software.
Just my half cent.
Thanks again and have a nice day.
P.

In the time it takes to read these threads you could have learned to use the transform control and the crop/perspective tool to do nearly everything except correct fisheye images.
With practice you can make reasonable corrections by eye in seconds for most amateur perspective problems.
Its much easier than tilting an easel under an enlarger. If you understand the process, including capture of the original image, PS is much cheaper than a PC lens and no one will ever know the difference! These processes are invaluable if you ever have to document large, flat pieces of art and it is physically impossible to ideally orient the lens and camera.

— —

"Paolo" wrote in message

Hello everybody,
I’ve googled a long time before coming and asking.
I’m considering to buy a graphic/retouching program and I was thinking about photoshop.
Problem is, I often have to correct huge amounts of badly taken photos and I often need to apply massive perspective corrections/distorsions. The Lens Correction tool is ok, but not fast enough (by the time you set the horizontal perspective correctly, the vertical goes all wrong and you have to overshoot the correction on one axis to get it right in a few tries).
I also need to correct both the horizontal and vertical axis, not just one (i.e.: the "horizon line" thingy is totally useless for me). This is my question: is there any way to tell PS (or, FWIW, any other similar program) to distort/adjust as a rectangle a given quadrilateral whose vertices I click-set directly on the image, maybe with a simple average of x and y coordinates – that shouldn’t be so difficult to implement?
Tnx in advance,
P

You could give this a try:

http://www.dxo.com/uk/photo
Keystoning correction (1)
Although not an optical defect per se, keystoning perspective distortion resulting from the camera’s sensor not being perfectly parallel to the subject is something many users would like to have control over, without resorting to the use of technical cameras or special shift lenses. With this new feature, all of your lenses in effect become ‘shift’ lenses, greatly widening your photographic possibilities!
http://www.dxo.com/uk/photo/dxo_optics_pro/optics_geometry_c orrections/keystoning#1

Richard