Gmagick::separateimagechannel

(PECL gmagick >= Unknown)

Gmagick::separateimagechannel — Separates a channel from the image

public Gmagick Gmagick::separateimagechannel ( int $channel )

Separates a channel from the image and returns a grayscale image. A channel is a particular color component of each pixel in the image.

channel: Identify which channel to extract: RedChannel, GreenChannel, BlueChannel, OpacityChannel, CyanChannel, MagentaChannel, YellowChannel, BlackChannel.

The Gmagick object on success

错误时抛出GmagickException.