unpremultiplyingAlpha()
Returns a new image created by dividing the image’s RGB values by its alpha values.
Declaration
func unpremultiplyingAlpha() -> CIImageReturn Value
An image object representing the result of the operation.
Discussion
Premultiplied alpha speeds up the rendering of images, but some custom filter routines can be expressed more efficiently with non-premultiplied RGB values. Use this method if you need to apply such a filter to an image that has premultiplied alpha.
See Also
Creating an Image by Modifying an Existing Image
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