ImagickPixel::getColor()

(PECL imagick 2.0.0)

Returns the color

说明

ImagickPixel::getColor([int $normalized= 0]): array

Returns the color described by the ImagickPixel object, as an array. If the color has an opacity channel set, this is provided as a fourth value in the list.

参数

$normalized

Normalize the color values

返回值

An array of channel values, each normalized if TRUE is given as param. Throws ImagickPixelException on error.

范例

Example #1 Basic Imagick::getColor() usage

<?php
//Create an ImagickPixel with the predefined color 'brown'
$color = new ImagickPixel('brown');
//Set the color to have an alpha of 25%
$color->setColorValue(Imagick::COLOR_ALPHA, 64 / 256.0);
$colorInfo = $color->getColor();
echo "Standard values".PHP_EOL;
print_r($colorInfo);
$colorInfo = $color->getColor(true);
echo "Normalized values:".PHP_EOL;
print_r($colorInfo);
?>

以上例程会输出：

Standard values
Array
(
    [r] => 165
    [g] => 42
    [b] => 42
    [a] => 0
)
Normalized values:
Array
(
    [r] => 0.64705882352941
    [g] => 0.16470588235294
    [b] => 0.16470588235294
    [a] => 0.25000381475547
)
    

In case you use default un-normalized getColor value the alpha value will always be either 0 or 1.
If you want to use real full-range 0-1 alpha channel on your 24bit transparent images use the alpha value from the normalized one, even if you use the rest of unnormalized data.
To copy a 24bit png with real alpha transparency, you would have to do this:
<?php
$im=new Imagick( 'image.png' );
$iterator=$im->getPixelIterator();
foreach ($iterator as $row=>$pixels) {
  foreach ( $pixels as $column => $pixel ){
    $un_color=$pixel->getColor(); //unnormalized color
    $nor_color=$pixel->getColor(true); //normalized color
    $pixel->setColor('rgba('.$un_color['r'].','.$un_color['g'].','.$un_color['b'].','.$nor_color['a'].')');
  }
}
?>
If you use 'a' (alpha) value from the unnormalized color there will only be binary transparency.