Imagick::getPixelRegionIterator

(PECL imagick 2.0.0)

Imagick::getPixelRegionIterator — Get an ImagickPixelIterator for an image section

说明

Imagick::getPixelRegionIterator ( int $x , int $y , int $columns , int $rows ) : ImagickPixelIterator

Get an ImagickPixelIterator for an image section.

参数

x

The x-coordinate of the region.

y

The y-coordinate of the region.

columns

The width of the region.

rows

The height of the region.

返回值

Returns an ImagickPixelIterator for an image section.

错误／异常

错误时抛出 ImagickException。

范例

Example #1 Imagick::getPixelRegionIterator() example

Iterate over the pixels in the top left of the image, changing them to be black.

<?php
$im = new Imagick(realpath("./testImage.png"));
$areaIterator = $im->getPixelRegionIterator(0, 0, 10, 10);

foreach ($areaIterator as $rowIterator) {
    foreach ($rowIterator as $pixel) {
        // Paint every pixel black
        $pixel->setColor("rgba(0, 0, 0, 0)");
    }
    $areaIterator->syncIterator();
}
$im->writeImage("./output.png");
?>