The ImagickPixelIterator::getPreviousIteratorRow() function is an inbuilt function in PHP which is used to get the previous row as an array of pixel wands from the pixel iterator.
Syntax:
array ImagickPixelIterator::getPreviousIteratorRow( void )
Parameters: This function doesn’t accepts any parameters.
Return Value: This function returns an array value containing ImagickPixel objects.
Below programs illustrate the ImagickPixelIterator::getPreviousIteratorRow() function in PHP:
Program 1:
<?php // Create a new imagick object $imagick = new Imagick( // Get the pixel iterator $pixelIterator = $imagick->getPixelIterator(); // Set the pixel iterator to 50 $pixelIterator->setIteratorRow(50); // Move one step to previous row $pixelIterator->getPreviousIteratorRow(); // Get the current iterator row echo "Current row is " . $pixelIterator->getIteratorRow(); ?> |
Output:
Current row is 49
Program 2:
<?php // Create a new imagick object $imagick = new Imagick(); // Create a image on imagick object $imagick->newImage(800, 250, 'black'); $imageIterator = $imagick->getPixelIterator(); $x = 0; // Set the iterator row to last row $imageIterator->setIteratorRow(249); while ($x < 250) { // Get the previous row $pixels = $imageIterator->getPreviousIteratorRow(); foreach ($pixels as $pixel) { if ($x % 4) { // Set the color of pixel $pixel->setColor('green'); } else { // Set the color of pixel $pixel->setColor('red'); } } // Sync the iterator $imageIterator->syncIterator(); $x++; } // Show the output $imagick->setImageFormat('png'); header("Content-Type: image/png"); echo $imagick->getImageBlob(); ?> |
Output:
Reference: https://www.php.net/manual/en/imagickpixeliterator.getpreviousiteratorrow.php
