Home
Newslog
Audio Processing
Image Processing
  Color Cube
  Color Replacer
  Contrast Mask
  Hue Restorer
  Pano Warp
  Perspective Transf.
  Pinocchio
  Sliding Tile Puzzle
  Vignette Corrector
  Wire Worm
Articles
Music
Gallery
Links
Donate
Contact

 

Perspective Transformations

Sometimes you cannot choose the optimum angle to take a picture. If the object is essentially planar (e.g. a painting on a wall) or the angle is not off by much then there is hope that you can correct the perspective afterwards.

The opposite may also be of interest if you want to make a composition and place objects at different angles, e.g. pep up screenshots for a brochure.

The Perspective plugin lets you carry out both active ("Modify") and passive ("Rectify") transformations. You can rotate the image around three axes, then reposition and resize it. Grid lines can be displayed both before and after transformation.

Here is a screenshot of the Perspective Transformations plugin:

Perspective Tranformations GUI 

History of Changes

Version 8.2 (current version)
  • Help button and tooptips option
Version 8.0
  • Support for 16 bit/channel images
  • Support for grayscale images
Version 7.9
  • Support for left-handed mouse settings
Version 7.8

  • Snap function for easier positioning of control lines
  • Selectable control lines color
  • Resizeable dialog
  • Minor bug fixes

Version 7.5

  • Use shift key to magnify region of interest for accurate placement of control points
  • New user-friendly Crop section replaces previous Positioning section

Version 7

  • Set control points in the preview image. The plugin evaluates these control points and sets the slider values accordingly to rectify the image.
  • Choose between various rectification modes
  • De-barrel slider to compensate barrel or pincushion lens distortions. Comes in handy for architecture photography.
  • Larger GUI and image preview
  • Finer slider increments for higher precision
  • Track option to enable/disable instant preview
  • Automatic positioning works even with non-zero rotation
  • Various minor bugs fixed

Awards

Perspective Transformations got the editor's recommendation in a test by DigitalPHOTO.

Recommendation by DigitalPHOTO 

Downloads

Download Perspective Transformations

Examples

As an example take the following detail of "La casa de los azulejos" in Mexico City.

This is the original shot: And here is the corrected image:
La casa de los azulejos La casa de los azulejos - corrected

The next example is the Edificio Reforma Avantel, also in Mexico City. The sequence shows how you can transform the image using control points to mark a rectangle.

original marked rectangle
corrected rectangle final image

Related Stuff

ShiftN is a clever freeware application for automatic correction of converging lines in images by applying a perspective transformation similar to the optical effect of a shift lens, hence the name. ShiftN will detect and correct converging lines automatically, however manual adjustments are also possible.

   © 2009 by Martin Vicanek