(PECL gmagick >= Unknown)
GmagickPixel::setcolorvalue — Sets the normalized value of one of the channels
Sets the value of the specified channel of this object to the provided value, which should be between 0 and 1. This function can be used to provide an opacity channel to a GmagickPixel object.
One of the Gmagick channel color constants.
The value to set this channel to, ranging from 0 to 1.
The GmagickPixel object on success.