Question to users of Photoshop and other advanced image editors

ofnuts · **Joined:** Oct 25, 2010 **Posts:** 4812

If you use the perspective correction tool of your editor to get a "straight" image with 3x5 tiles, do you get truly square squares right away, of do you have to tweak the results (rescale in one dimension)?

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Rod · **Joined:** May 16, 2010 **Posts:** 16170

First try - CS5 12

ofnuts · **Joined:** Oct 25, 2010 **Posts:** 4812

By "straight" I meant this (squared?):

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FloorTiles-corrected.JPG [ 27.31 KiB | Viewed 2991 times ]

kimppi · **Joined:** Feb 17, 2011 **Posts:** 225

Doesn't that depend on how much "barreling" your camera lense makes?

One image might straigten up better than other, depending distance, zoom and other factors. I do not believe that any image editor can analyze that automatically.

Also some lenses give uneven(!) barreling, which is, well, tricky thing to correct. Noise can also trick eye when correcting, so there are problems even in manual work.

However, Gimp's perspective etc. tools are handy, but I believe that there are other free option for this kind of functionality. I think I read something when I searched for photo stitchers. Unfortunately I can't find links now.

Disclaimer: I'm not professional photographer or image editor.

kimppi · **Joined:** Feb 17, 2011 **Posts:** 225

Not what I found earlier, but this might be of use:

Hugin tutorial about subject:

http://hugin.sourceforge.net/tutorials/architectural/en.shtml

bkh1914 · **Posted:** Sun Sep 25, 2011 7:08 am **(#6)**

I know the question is how other programs handle perspective change, but are you aware of the EZ-Perspective plug-in? It appears to be a GIMP answer to your question.

PhotoComix · **Joined:** Apr 12, 2010 **Posts:** 5870

I didn't reply before because i don't use PS often, more i mostly used the perspective corretion tools for artistic effect seldom for tecnical correction (even if that is the main use)

Short reply, yes PS may do quickly and very well

Longer reply

PS has 2 main tool to correct perspective,

1) is the most know because in PS from very long time ,but not the most advanced
It is the lens distortion filter
here the official description
http://help.adobe.com/en_US/Photoshop/1 ... EEEE10D82a

[b]It is my favorite transforming tool(less know and described in the web because it is a almost new feature ...and it rocks)[/b]
This the short description
"

Quote:

The retouch and transform features in Adobe® Photoshop® CS4 let you alter your images to accomplish a variety of tasks—to improve a composition, correct distortions or flaws, creatively manipulate picture elements, add or remove items, sharpen or blur, or merge multiple images into a panorama. The Vanishing Point feature lets you retouch and paint according to the perspective of an image. The Adobe® Photoshop® CS4 Extended version of Vanishing Point also lets you make measurements of items in an image and export the measurements along with geometric information and textures for use in 3D applications."

Here the official doc
http://help.adobe.com/en_US/Photoshop/1 ... 763ea.html

http://help.adobe.com/en_US/Photoshop/1 ... 763ea.html

ofnuts · **Joined:** Oct 25, 2010 **Posts:** 4812

kimppi wrote:

Doesn't that depend on how much "barreling" your camera lense makes?

even perfect lenses produces converging lines in these cases.

ofnuts · **Joined:** Oct 25, 2010 **Posts:** 4812

bkh1914 wrote:

I know the question is how other programs handle perspective change, but are you aware of the EZ-Perspective plug-in? It appears to be a GIMP answer to your question.

Interesting and likely useful... but the "EZ" prefix is wishful thinking...

ofnuts · **Joined:** Oct 25, 2010 **Posts:** 4812

PhotoComix wrote:

I didn't reply before because i don't use PS often, more i mostly used the perspective corretion tools for artistic effect seldom for tecnical correction (even if that is the main use)

Short reply, yes PS may do quickly and very well...

OK, thanks for the explanation.