PHP Manual: Sets the normalized value of one of the channels

Description

public bool ImagickPixel::setColorValue(int $color, float $value)

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.

Parameters

color: One of the Imagick color constants e.g. \Imagick::COLOR_GREEN or \Imagick::COLOR_ALPHA.
value: The value to set this channel to, ranging from 0 to 1.

Return Values

Returns true on success.

Examples

Example #1 Basic Imagick::setColorValue usage

<?php

$color  = new \ImagickPixel('firebrick');

$color->setColorValue(Imagick::COLOR_ALPHA, 0.5);

print_r($color->getcolor(true));
?>

The above example will output:

Array
(
    [r] => 0.69803921568627
    [g] => 0.13333333333333
    [b] => 0.13333333333333
    [a] => 0.50000762951095
)