The Simple Choker effect shrinks or expands the edges of a matte in small increments to create a cleaner matte. The Final Output view displays the image with the effect applied, and the Matte view provides a black-and-white view of the image with black areas indicating transparency and white areas indicating opacity. Choke Matte sets the amount of choke. Negative values spread the matte; positive values choke it.

This effect works with 8-bpc and 16-bpc color.

Original (top left) contains unwanted edges after keying (bottom left) that are removed with Simple Choker (bottom right).