PHP | ImagickPixelIterator setIteratorFirstRow() Function

The ImagickPixelIterator::setIteratorFirstRow() function is an inbuilt function in PHP which is used to set the pixel iterator to the first pixel row.

Syntax:

bool ImagickPixelIterator::setIteratorFirstRow( void )

Parameters: This function doesn’t accepts any parameter.

Return Value: This function returns TRUE on success.

Below programs illustrate the ImagickPixelIterator::setIteratorFirstRow() function in PHP:

Program 1:

<?php

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

// Get the pixel iterator
$pixelIterator = $imagick->getPixelIterator();

// Set the pixel iterator to 50
$pixelIterator->setIteratorRow(50);

// Get the current iterator row
echo "Current row is " . $pixelIterator->getIteratorRow();

// Set the iterator to first row
$pixelIterator->setIteratorFirstRow();

// Get the current iterator row
echo "<br>Current row is " . $pixelIterator->getIteratorRow();
?>

Output:

Current row is 50
Current row is 0

Program 2:

<?php

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

// Get the pixel iterator
$pixelIterator = $imagick->getPixelIterator();

$pixelIterator->setIteratorRow(40);

// Get the current iterator row
$row = $pixelIterator->getCurrentIteratorRow();
echo "Colors of 61th and 62nd pixel from 40th row are:<br>";
print("Pixel 60:" . "<pre>".print_r($row[60]->getColor(), true)."</pre>");
print("Pixel 61:" . "<pre>".print_r($row[61]->getColor(), true)."</pre>");

// Set the iterator to first row
$pixelIterator->setIteratorFirstRow();

// Get the current iterator row
$row = $pixelIterator->getCurrentIteratorRow();
echo "First two colors of pixels from first row are:<br>";
print("Pixel 1:" . "<pre>".print_r($row[0]->getColor(), true)."</pre>");
print("Pixel 2:" . "<pre>".print_r($row[1]->getColor(), true)."</pre>");
?>

Output:

Colors of 61th and 62nd pixel from 40th row are:
Pixel 60:
Array
(
    [r] => 110
    [g] => 199
    [b] => 131
    [a] => 1
)
Pixel 61:
Array
(
    [r] => 23
    [g] => 165
    [b] => 57
    [a] => 1
)
First two colors of pixels from first row are:
Pixel 1:
Array
(
    [r] => 255
    [g] => 255
    [b] => 255
    [a] => 1
)
Pixel 2:
Array
(
    [r] => 255
    [g] => 255
    [b] => 255
    [a] => 1
)

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