private function ordered($image)
{
// Localize vars
$width = $image->getWidth();
$height = $image->getHeight();
$thresholdMap = array(array(15, 135, 45, 165), array(195, 75, 225, 105), array(60, 180, 30, 150), array(240, 120, 210, 90));
// Loop using image1
$pixelIterator = $image->getCore()->getPixelIterator();
foreach ($pixelIterator as $y => $rows) {
/* Loop through pixel rows */
foreach ($rows as $x => $px) {
/* Loop through the pixels in the row (columns) */
/**
* @var $px \ImagickPixel */
$rgba = $px->getColor();
$gray = round($rgba['r'] * 0.3 + $rgba['g'] * 0.59 + $rgba['b'] * 0.11);
$threshold = $thresholdMap[$x % 4][$y % 4];
$oldPixel = ($gray + $threshold) / 2;
if ($oldPixel <= 127) {
// Determine if black or white. Also has the benefit of clipping excess value
$newPixel = 0;
} else {
$newPixel = 255;
}
// Current pixel
$px->setColor("rgb({$newPixel},{$newPixel},{$newPixel})");
}
$pixelIterator->syncIterator();
/* Sync the iterator, this is important to do on each iteration */
}
$type = $image->getType();
$file = $image->getImageFile();
$image = $image->getCore();
return new Image($image, $file, $width, $height, $type);
// Create new image with updated core
}
