Imagick::getPixelIterator

(PECL imagick 2, PECL imagick 3)

Imagick::getPixelIteratorReturns a MagickPixelIterator

Description

public Imagick::getPixelIterator(): ImagickPixelIterator

Returns a MagickPixelIterator.

Parameters

This function has no parameters.

Return Values

Returns an ImagickPixelIterator on success.

Errors/Exceptions

Throws ImagickException on error.

Examples

Example #1 Imagick::getPixelIterator()

<?php
function getPixelIterator($imagePath) {
$imagick = new \Imagick(realpath($imagePath));
$imageIterator = $imagick->getPixelIterator();

foreach (
$imageIterator as $row => $pixels) { /* Loop through pixel rows */
foreach ($pixels as $column => $pixel) { /* Loop through the pixels in the row (columns) */
/** @var $pixel \ImagickPixel */
if ($column % 2) {
$pixel->setColor("rgba(0, 0, 0, 0)"); /* Paint every second pixel black*/
}
}
$imageIterator->syncIterator(); /* Sync the iterator, this is important to do on each iteration */
}

header("Content-Type: image/jpg");
echo
$imagick;
}

?>

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User Contributed Notes 1 note

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Sebastian Herold
17 years ago
For me it was very helpful to read a article at Mikko's blog. He showed that the PixelIterator is not read-only, if you sync it regularly:<?php      /* Create new object with the image */      $im = new Imagick( "strawberry.png" );      /* Get iterator */      $it = $im->getPixelIterator();             /* Loop trough pixel rows */      foreach( $it as $row => $pixels )      {          /* For every second row */          if ( $row % 2 )          {              /* Loop trough the pixels in the row (columns) */              foreach ( $pixels as $column => $pixel )              {                      /* Paint every second pixel black*/                      if ( $column % 2 )                      {                              $pixel->setColor( "black" );                      }              }          }                   /* Sync the iterator, this is important to do on each iteration */          $it->syncIterator();      }             /* Display the image */      header( "Content-Type: image/png" );      echo $im;       ?>
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