colorlevels

Adjust video input frames using levels.

The filter accepts the following options:

'rimin'

'gimin'

'bimin'

'aimin'

Adjust red, green, blue and alpha input black point. Allowed ranges for options are [-1.0, 1.0]. Defaults are 0.

'rimax'

'gimax'

'bimax'

'aimax'

Adjust red, green, blue and alpha input white point. Allowed ranges for options are [-1.0, 1.0]. Defaults are 1.

Input levels are used to lighten highlights (bright tones), darken shadows (dark tones), change the balance of bright and dark tones.

'romin'

'gomin'

'bomin'

'aomin'

Adjust red, green, blue and alpha output black point. Allowed ranges for options are [0, 1.0]. Defaults are 0.

'romax'

'gomax'

'bomax'

'aomax'

Adjust red, green, blue and alpha output white point. Allowed ranges for options are [0, 1.0]. Defaults are 1.

Output levels allows manual selection of a constrained output level range.

Command line examples

• Make video output darker:

  colorlevels=rimin=0.058:gimin=0.058:bimin=0.058
  

• Increase contrast:

  colorlevels=rimin=0.039:gimin=0.039:bimin=0.039:rimax=0.96:gimax=0.96:bimax=0.96
  

• Make video output lighter:

  colorlevels=rimax=0.902:gimax=0.902:bimax=0.902
  

• Increase brightness:

  colorlevels=romin=0.5:gomin=0.5:bomin=0.5