Color Key Feather

The colorkey-feather parameter softens the edge of a colorkey. Pixels within colorkey-tol of the key are fully transparent. Past that, transparency fades out linearly over the next colorkey-feather units of color distance, so a pixel colorkey-tol + colorkey-feather away is fully opaque. It has no effect without colorkey.

The value uses the same unit as colorkey-tol. The default is 30 in color mode and 18.03 in chroma mode. Set colorkey-feather=0 for a hard edge, where every pixel is either fully transparent or fully opaque.

colorkeyfeather is accepted as an alias.

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