colorkey

RGB colorspace color keying.

The filter accepts the following options:

'color'

The color which will be replaced with transparency.

'similarity'

Similarity percentage with the key color.

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

'blend'

Blend percentage.

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.

Command line examples

• Make every green pixel in the input image transparent:

  ffmpeg -i input.png -vf colorkey=green out.png
  

• Overlay a greenscreen-video on top of a static background image.

  ffmpeg -i background.png -i video.mp4 -filter_complex "[1:v]colorkey=0x3BBD1E:0.3:0.2[ckout];[0:v][ckout]overlay[out]" -map "[out]" output.flv