PHP | ImagickPixelIterator __construct() function

The ImagickPixelIterator::__construct() function is an inbuilt function in PHP which is used create a instance of ImagickPixelIterator object. This object is used to iterate through the pixels.

Syntax:

bool ImagickPixelIterator::__construct( Imagick $wand )

Parameters:This function accepts a single parameter $wand which holds the image.

Return Value: This function returns TRUE on success.

Exceptions: This function throws ImagickException on error.

Below given programs illustrate the ImagickPixelIterator::__construct() function in PHP:
Program 1:

<?php
// Create a new imagick object
$imagick = new Imagick();

// Create a image on imagick object
$imagick->newImage(800, 250, 'black');

// Create a new imagickPixelIterator object
$imageIterator = new ImagickPixelIterator($imagick);

// Loop through pixel rows
foreach ($imageIterator as $row => $pixels) {

    foreach ($pixels as $column => $pixel) {
        // Set the color of each pixel to blue
        $pixel->setColor('blue');
    }

    // Sync the iterator after each iteration
    $imageIterator->syncIterator();
}

// Show the output
$imagick->setImageFormat('png');
header("Content-Type: image/png");
echo $imagick->getImageBlob();
?>

Output:

Program 2:

<?php
// Create a new imagick object
$imagick = new Imagick(
    'https://media.geeksforgeeks.org/wp-content/uploads/geeksforgeeks-13.png');

// Create a new imagickPixelIterator object
$imageIterator = new ImagickPixelIterator($imagick);

$i = 0;

// Loop through pixel rows
foreach ($imageIterator as $row => $pixels) {

    foreach ($pixels as $column => $pixel) {
        $i++;
    }

    // Sync the iterator after each iteration
    $imageIterator->syncIterator();
}

echo 'Total number of pixels: ' . $i;
?>

Output:

Total number of pixels: 122728

Reference: https://www.php.net/manual/en/imagickpixeliterator.construct.php