ImagickPixel::getColor

(PECL imagick 2, PECL imagick 3)

ImagickPixel::getColor — Returns the color

说明

public 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. Possible values are 0, 1 or 2.

**List of possible values for `normalized`**
`normalized`	Description
`0`	The RGB values are returned as ints in the range `0` to `255` (inclusive.) The alpha value is returned as int and is either `0` or `1`.
`1`	The RGBA values are returned as floats in the range `0` to `1` (inclusive.)
`2`	The RGBA values are returned as ints in the range `0` to `255` (inclusive.)

返回值

An array of channel values. Throws ImagickPixelException on error.

范例

示例 #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(1);

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
)

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User Contributed Notes 1 note

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roman ¶

9 years ago


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.

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