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 $im;
?>
Imagick::getPixelIterator
(PECL imagick 2, PECL imagick 3)
Imagick::getPixelIterator — Returns a MagickPixelIterator
Beschreibung
Returns a MagickPixelIterator.
Parameter-Liste
Diese Funktion besitzt keine Parameter.
Rückgabewerte
Returns an ImagickPixelIterator on success.
Fehler/Exceptions
Wirft ImagickException bei Fehlern.
Beispiele
Beispiel #1 Imagick::getPixelIterator()
<?php
function getPixelIterator($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
Sebastian Herold ¶
16 years ago
