Barrel distortion

This is stub article and needs to be expanded by somebody with pictures etc.. please go ahead.

Barrel distortion is the opposite of pincushion distortion.

Tools to correct barrel distortion

• The original PTStitcher can be scripted to batch process images with known a, b & c parameters. It can also be operated with one of the GUI tools such as PTGui, PTAssembler, hugin or PTMac.

• nona or nona_gui (both part of the hugin distribution) can be used identically to PTStitcher.

• The Correct filter in the Panorama Tools Plugins for the gimp or photoshop uses the same a, b & c parameters as PTStitcher. Note that it doesn't know about d & e parameters and uses 'd' as an overall scaling factor instead.

• PTLens is a Photoshop plugin and a stand-alone Windows tool that uses the same a, b & c parameters and comes with a database of popular lenses.

• Clens is a command line version of PTLens.

• Gimp wideangle plugin uses a different formula altogether to correct distortion.

• Gimp phfluuh plugin is another tool that corrects lens distortion using yet another formula.

• CamChecker is a tool for automatically determining lens distortion and generates a different set of parameters from everything else.

• zhang_undistort is a tool ditributed with hugin that uses CamChecker parameters to actually correct distortion.