Turns a certain HSV range into transparency.

This filter measures color difference between set HSV color in options and ones measured in video stream. Depending on options, output colors can be changed to transparent by adding alpha channel.

The filter accepts the following options:

hue

Set the hue value which will be used in color difference calculation. Allowed range is from -360 to 360. Default value is 0.

sat

Set the saturation value which will be used in color difference calculation. Allowed range is from -1 to 1. Default value is 0.

val

Set the value which will be used in color difference calculation. Allowed range is from -1 to 1. Default value is 0.

similarity

Set similarity percentage with the key color. Allowed range is from 0 to 1. Default value is 0.01.

0.00001 matches only the exact key color, while 1.0 matches everything.

blend

Blend percentage. Allowed range is from 0 to 1. Default value is 0.

0.0 makes pixels either fully transparent, or not transparent at all.

Higher values result in semi-transparent pixels, with a higher transparency the more similar the pixels color is to the key color.