Is there a trick in Photoshop Elements for correcting perspective
distortion? The perspective transformation has linear correction for
the width of the image, but it doesn't have the non-linear correction
for length. The side of the image that is widened looks squashed in the
other dimension.
I'm using the Canon 10-22 EF-S. It's a fun lens but the tiniest
misalignment is a huge problem. Sometimes I don't realize that I was a
little bit off until I have the photo on the computer. It's especially
bad for night photography when the viewfinder isn't very usable
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In article <mcmurtri-841573.23510511042008
@softbank060082049208.bbtec.net>, Kevin McMurtrie says...
> Is there a trick in Photoshop Elements for correcting perspective
> distortion? The perspective transformation has linear correction for
> the width of the image, but it doesn't have the non-linear correction
> for length. The side of the image that is widened looks squashed in the
> other dimension.
>
> I'm using the Canon 10-22 EF-S. It's a fun lens but the tiniest
> misalignment is a huge problem. Sometimes I don't realize that I was a
> little bit off until I have the photo on the computer. It's especially
> bad for night photography when the viewfinder isn't very usable
PTLens isn't bad, but I don't know if it runs in Elements.
--
Kevin McMurtrie wrote:
> Is there a trick in Photoshop Elements for correcting perspective
> distortion? The perspective transformation has linear correction for
> the width of the image, but it doesn't have the non-linear correction
> for length. The side of the image that is widened looks squashed in the
> other dimension.
>
> I'm using the Canon 10-22 EF-S. It's a fun lens but the tiniest
> misalignment is a huge problem. Sometimes I don't realize that I was a
> little bit off until I have the photo on the computer. It's especially
> bad for night photography when the viewfinder isn't very usable
>
I don't have Elements but I suspect it works much like full Photoshop.
1) With the rectangle selection tool, outline all or part of image you
want to edit.
2) Go to EDIT > TRANSFORM > PERSPECTIVE......A bounding box will appear.
3) Grab one corner of the bounding box and move it so the perspective
looks right.
Bob Williams
Alfred Molon wrote:
> In article <mcmurtri-841573.23510511042008
> @softbank060082049208.bbtec.net>, Kevin McMurtrie says...
>> Is there a trick in Photoshop Elements for correcting perspective
>> distortion? The perspective transformation has linear correction for
>> the width of the image, but it doesn't have the non-linear correction
>> for length. The side of the image that is widened looks squashed in the
>> other dimension.
>>
>> I'm using the Canon 10-22 EF-S. It's a fun lens but the tiniest
>> misalignment is a huge problem. Sometimes I don't realize that I was a
>> little bit off until I have the photo on the computer. It's especially
>> bad for night photography when the viewfinder isn't very usable
>
> PTLens isn't bad, but I don't know if it runs in Elements.
Open image, from top line menu [Image] [Transform] [Perspective].
"Alfred Molon" <alfred_molon@yahoo.com> wrote in message
news:MPG.226a7da7a2081b3398bb77@news.supernews.com ...
> In article <mcmurtri-841573.23510511042008
> @softbank060082049208.bbtec.net>, Kevin McMurtrie says...
>> Is there a trick in Photoshop Elements for correcting perspective
>> distortion? The perspective transformation has linear correction for
>> the width of the image, but it doesn't have the non-linear correction
>> for length. The side of the image that is widened looks squashed in the
>> other dimension.
>>
>> I'm using the Canon 10-22 EF-S. It's a fun lens but the tiniest
>> misalignment is a huge problem. Sometimes I don't realize that I was a
>> little bit off until I have the photo on the computer. It's especially
>> bad for night photography when the viewfinder isn't very usable
>
> PTLens isn't bad, but I don't know if it runs in Elements.
> --
>
> Alfred Molon
> ------------------------------
> Olympus 50X0, 8080, E3X0, E4X0, E5X0 and E3 forum at
> http://tech.groups.yahoo.com/group/MyOlympus/
> http://myolympus.org/ photo sharing site
Alfred Molon wrote:
> In article <ftqfo0$cl9$1@news.acm.uiuc.edu>, says...
>
>> I suggest Panorama Tools or Hugin.
>
> Can you integrate them into Elements or Photoshop, or are they
> standalone applications?
Hugin is a panorama program that is a "wrapper" for Panorama Tools, but can
be used to remap single files.
Panorama Tools can run as a Photshop plugin. It is not user
friendly as such.
In article <7L%Lj.83372$497.82031@newsfe14.phx>,
Bob Williams <mytbobnospam@cox.net> wrote:
> Kevin McMurtrie wrote:
> > Is there a trick in Photoshop Elements for correcting perspective
> > distortion? The perspective transformation has linear correction for
> > the width of the image, but it doesn't have the non-linear correction
> > for length. The side of the image that is widened looks squashed in the
> > other dimension.
> >
> > I'm using the Canon 10-22 EF-S. It's a fun lens but the tiniest
> > misalignment is a huge problem. Sometimes I don't realize that I was a
> > little bit off until I have the photo on the computer. It's especially
> > bad for night photography when the viewfinder isn't very usable
> >
> I don't have Elements but I suspect it works much like full Photoshop.
> 1) With the rectangle selection tool, outline all or part of image you
> want to edit.
> 2) Go to EDIT > TRANSFORM > PERSPECTIVE......A bounding box will appear.
> 3) Grab one corner of the bounding box and move it so the perspective
> looks right.
> Bob Williams
As I mentioned, the perspective transformation is missing half of the
equation needed for correction. It makes the lines straight but
relative dimensions remain incorrect. For example, a photo taken is
turned slightly to the right so horizontal lines point inwards on the
right and outwards on the left. You use the perspective transformation
to make the right side taller or the left side shorter. Now the all
lines are straight but the right side is squashed horizontally while the
left side is stretched horizontally. The tool is missing a nonlinear
stretch.
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Kevin McMurtrie wrote:
> In article <7L%Lj.83372$497.82031@newsfe14.phx>,
> Bob Williams <mytbobnospam@cox.net> wrote:
>
>> Kevin McMurtrie wrote:
>>> Is there a trick in Photoshop Elements for correcting perspective
>>> distortion? The perspective transformation has linear correction for
>>> the width of the image, but it doesn't have the non-linear correction
>>> for length. The side of the image that is widened looks squashed in the
>>> other dimension.
>>>
>>> I'm using the Canon 10-22 EF-S. It's a fun lens but the tiniest
>>> misalignment is a huge problem. Sometimes I don't realize that I was a
>>> little bit off until I have the photo on the computer. It's especially
>>> bad for night photography when the viewfinder isn't very usable
>>>
>> I don't have Elements but I suspect it works much like full Photoshop.
>> 1) With the rectangle selection tool, outline all or part of image you
>> want to edit.
>> 2) Go to EDIT > TRANSFORM > PERSPECTIVE......A bounding box will appear.
>> 3) Grab one corner of the bounding box and move it so the perspective
>> looks right.
>> Bob Williams
>
> As I mentioned, the perspective transformation is missing half of the
> equation needed for correction. It makes the lines straight but
> relative dimensions remain incorrect. For example, a photo taken is
> turned slightly to the right so horizontal lines point inwards on the
> right and outwards on the left. You use the perspective transformation
> to make the right side taller or the left side shorter. Now the all
> lines are straight but the right side is squashed horizontally while the
> left side is stretched horizontally. The tool is missing a nonlinear
> stretch.
>
Try freeware - the Gimp.
PC functions are good.
Look at "clipping" option or resize the canvas before applying PC, so
that parts of the image stretched beyond the border aren't lost.
Toggle preview grid, grid and image etc.
Toggle between corrective and normal.
Select interpolation - Gimp has Lanczos, generally better than Cubic.
(suggested to just try these - should be easier for you to see what's
happening rather than me trying to explain).
Gimp also has "perspective clone" tool, similar to "vanishing point"
tool in Photoshop CS2/3.
frederick wrote:
>>> Kevin McMurtrie wrote:
>>>> Is there a trick in Photoshop Elements for correcting perspective
>>>> distortion? The perspective transformation has linear correction
>>>> for the width of the image, but it doesn't have the non-linear
>>>> correction for length. The side of the image that is widened looks
>>>> squashed in the other dimension.
>
> Gimp also has "perspective clone" tool, similar to "vanishing point"
> tool in Photoshop CS2/3.
Ah, I get it.
No, I never heard of such a tool though the perspective clone idea is
the same principal. You almost would have to project the image onto a
cylindrical surface to correct that.
Another example:
Pointing the camera up towards a tall building, the sides taper in so
you stretch the sides back out on top till all is vertical and stretch
the overall vertical a little to compensate but still the windows at the
top have a closer vertical spacing than the ground floor windows.
Correcting perspective distortion 
Linear Mode
