Imagick::getPixelIterator

(PECL imagick 2, PECL imagick 3)

Imagick::getPixelIteratorReturns a MagickPixelIterator

Beschreibung

public Imagick::getPixelIterator(): ImagickPixelIterator

Returns a MagickPixelIterator.

Parameter-Liste

Diese Funktion besitzt keine Parameter.

Rückgabewerte

Returns an ImagickPixelIterator on success.

Fehler/Exceptions

Wirft ImagickException bei Fehlern.

Beispiele

Beispiel #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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1
Sebastian Herold
15 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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