Perspective and Barrel Distortion Correction of Wide-Angle Images in Paint Shop Pro


Original image

This image was shot in the "Desert Passage" shopping area of the Aladdin Hotel in Las Vegas.

It was shot with a Nikon CP990 digital camera with the equivalent of a 24mm wide-angle lens on a 35mm camera.

Since shooting position was restricted, the camera was tilted producing a strong keystone effect. This tutorial deals with fixing it.


Rotating


Grid Menu
Grid Properties

A grid is an invaluable reference in this process.

Select the grid via the "View" menu.

The width of grid can be adjusted by selecting "Change Grid and Guide Properties". Note the slant of the light pole.


Rotate image

Select "Rotate" from the Image menu.

Use the Rotate window to set the angle of rotation. If you don't guess it right, use Undo and continue with a process of elimination till correct.


Image rotated

 

And here is the image rotated.

Ignore the corners for the time being.


Perspective Correction


Finding "Perspective-Vertical" on the menu
Find Perspective - Vertical under Geometric Effects on the Effects menu.

Using Perspective - Vertical Change the % Difference value until the vertical lines visually line up with the grid.

Barrel Distortion


Finding "Warp" on the menu

Most wide-angle lenses exhibit a bit of barrel distortion.

To correct this, choose "Warp" - again under Geometric Effects on the Effects menu.


Warp tool

Warp is a very powerful tool for correcting barrel distortion.

(Or introducing distortion in any part of the image!)

In most cases, one can leave the offset at the default zeros, and the size at 100. However, if the image has been cropped, the adjustments are there.

 


Finished

Finally, crop it back to the image area and everything is complete.

 


For further discussion please go to any of the following forums that I frequent:

Yahoo! Groups PhotoGallery - http://groups.yahoo.com/group/PhotoGallery
Yahoo! Groups Coolpix990 - http://groups.yahoo.com/group/coolpix990
Yahoo! Groups nikon5000 - http://groups.yahoo.com/group/nikon5000
Yahoo! Groups digital-darkroom - http://groups.yahoo.com/group/digital-darkroom


Link to the Perspective Index page
Link to Larry Bolch.com