Correcting distortion

[AntonM]

Photographs often have a barrel or (less often) a pincushion distortion. The "Mould" tool in Xara seems ideal for correcting it, but the mathematics are a little beyond me.

Does anyone have any ideas how it might be done?

Anton

[AntonM]

Photographs often have a barrel or (less often) a pincushion distortion. The "Mould" tool in Xara seems ideal for correcting it, but the mathematics are a little beyond me.

Does anyone have any ideas how it might be done?

Anton

[Albacore]

Thr reply that you would like to hear is far to difficult for a plain designer to reply to. Sorry

[gwpriester]

Apply a Default Perspective Envelope to the photo.

Set up guidelines that you would like the sides to be parallel to and then drag the the top control points, or the top control points until the distortion has been removed.

You will need to make a bitmap copy of the corrected image. Then crop the image to a rectangle using either Apply Clipview or Combine Shapes... Intersect Shapes.

I would also recommend working with a higher resolution, e.g. 300dpi as you will have more pixels to work with. And a TIFF image is preferable to a JPEG for the initial image because a TIFF contains more pixel information, even if the pixels are not visible. A JPEG image just throws out the non-visible pixels.

Gary

[AntonM]

Thanks Gary -- that does work -- but only for rectilinear distortion.

Following on from your example, it would seem that barrel and pincusion distortions (very common in photographs) would require the Mould tool, but for some reason that doesn't do the job properly. It seems as if Mould has a "perspective" element to it, in that dragging a corner skews the picture as tyou would expect from "perspective", but the curved component is not applied, and instead Xara seems to want to tile the moulded object with the original bitimage.

Any ideas?

Anton

[MEB]

Hi Anton http://www.talkgraphics.com/images/smilies/biggrin.gif

Don´t drag the corner when using the Mould Tool (unless it´s really necessary).
Just select one of the corners (you can select more than one if necessary - just hold on SHIFT while selecting the corners), the control handles will appear. Use those control handles to correct/apply the "curved" component as you called it.


Cheers,
Miguel B.

[jens g.r. benthien]

Anton,

this is the stuff you are looking for:

http://photoshop.pluginsworld.com/pl...hop&plugin=242

It is freeware and works like a charm.

[AntonM]

Originally posted by Miguel B.:
Don´t drag the corner when using the Mould Tool (unless it´s really necessary).
[...snip...]
Use those control handles to correct/apply the "curved" component as you called it.

Thanks Miguel -- that changes the shape of the outline of the bitmap, but it doesn't change the "inside", as it were. It just tiles the original bitmap across the newly-distorted outline.

Anton

[AntonM]

Originally posted by jens g.r. benthien:
this is the stuff you are looking for:

http://photoshop.pluginsworld.com/pl...hop&plugin=242

It is freeware and works like a charm.

jens, is that only for Photoshop? or can one use it in Xara as well? I have Paintshop Pro, but Photoshop is out of my league.

Anton

[AntonM]

jens,

Okay, I posted without at least trying it out first!

Of course, it does work with Xara, and seems to do its job well. But the preview window remains black, whether I use a jpeg or whether I've converted it to a 32-bit or a 24-bit bitmap.

What am I doing wrong?

Anton