Gloom
Creates a muted, dark glow. The image is darkened, and areas of detail are evened out into larger regions of color. It’s spooky.
Adjust this filter using the parameter controls in the Filters Inspector:
Radius: Sets the radius of the gloom.
Amount: Sets the amount of gloom. Values range from 0 (no gloom) to 2 (maximum gloominess).
Mix: Sets the percentage of the original image to be blended with the filtered image.