premultipliedAlphaBlend(_:topLayer:destination:)
Performs alpha compositing of two 4-channel interleaved RGBA 8-bit pixel buffers using the specified blend mode to produce a premultiplied result.
Declaration
func premultipliedAlphaBlend(_ blendMode: vImage.BlendMode, topLayer: vImage.PixelBuffer<Format>, destination: vImage.PixelBuffer<Format>)Parameters
- blendMode:
The blend mode.
- topLayer:
The blend top layer.
- destination:
The destination pixel buffer.
Discussion
This function treats self as the bottom layer and both pixel buffers must have alpha as their last channel.