(PECL imagick 2, PECL imagick 3)
ImagickPixel::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 an ImagickPixel object.
colorOne of the Imagick color constants e.g. \Imagick::COLOR_GREEN or \Imagick::COLOR_ALPHA.
valueThe value to set this channel to, ranging from 0 to 1.
成功时返回 true。
示例 #1 Basic Imagick::setColorValue() usage
<?php
$color = new \ImagickPixel('firebrick');
$color->setColorValue(Imagick::COLOR_ALPHA, 0.5);
print_r($color->getcolor(true));
?>以上示例会输出：
Array
(
[r] => 0.69803921568627
[g] => 0.13333333333333
[b] => 0.13333333333333
[a] => 0.50000762951095
)