The Matte Choker effect repeats a sequence of choking and spreading the matte to fill undesired holes (transparent areas) in opaque regions. The repetition is necessary because the entire matte must be choked and spread; the spreading fills the hole, but the edges of the matte must be choked back to preserve the matte shape.

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

Original (top left) shows areas of unwanted transparency after using Color Key (bottom left) that are removed with Matte Choker (bottom right).