Imagick::getPixelIterator

    (PECL imagick 2, PECL imagick 3)

    Imagick::getPixelIterator — Returns 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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    1
    Sebastian Herold
    16 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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