bobdeng1974 / defish-1

"Defish" - barrel and pincushion distortion correction filter

Defish

"Defish" - barrel and pincushion distortion correction filter defish (v1.1) MT for Avisynth 2.5 (c) David Horman, 2010 Multithreaded version (c) 2011 Andrey "Efenstor" Pivovarov

This filter can be used to correct (or induce) barrel and pincushion distortion.

Links

• https://forum.doom9.org/showthread.php?t=152860
• http://horman.net/avisynth
• https://forum.doom9.org/showthread.php?p=1713391

USAGE

The filter takes the following parameters (in addition to the input clip):

• [unnamed] Input clip. Must be RGB32 and have even width/height.

• fov useful range: -180.0 - 180.0 default: 0 The horizontal field of view, in degrees. Positive values will correct barrel distortion (induce pincushioning). Negative values should correct pincushion distortion (induce barreling), but note that this may currently be implemented incorrectly.

• scale range: 0.0 - infinity default: 1.0 An adjustment parameter which scales the image after correction.

• aspect range: 0.0 - infinity default: 1.0 The pixel aspect ratio of the input clip.

• direction values: "x", "y" This parameter restricts the correction to either horizontal or vertical only.

• scaling values: "fitx", "fity", "fitxy" This parameter automatically scales the image to fill the image horizontally, vertically, or both. The "scale" parameter above is still effective.

  The default behaviour when using fov is to scale the image such that the central area stays at the original scale.

  This parameter is not effective when using the polynomial values below.

• a,b,c sensible range: 0.0 - 1.0 Parameters for correcting distortion polynomially. These are only effective when fov=0 (which is the default value).

    a+b+c must be less than or equal to 1.0 when pin=true.
  

• pin boolean Set this to true to correct pincushion distortion, and false to correct barrel distortion - this may seem the wrong way around but it was chosen to match the behaviour of the similar parameter of V.C. Mohan's DeBarrel filter.

• threads range: 0 - infinity 0 (default) sets the number of processing threads to the number of autodetected CPU's/cores.