--- /dev/null
+<?php
+/**
+ * Unsharp mask Image effect.
+ *
+ * Unsharp mask algorithm by Torstein Hønsi 2003 <thoensi_at_netcom_dot_no>
+ * From: http://www.vikjavev.com/hovudsida/umtestside.php
+ *
+ * @package Horde_Image
+ */
+class Horde_Image_Effect_Gd_Unsharpmask extends Horde_Image_Effect
+{
+ /**
+ * Valid parameters:
+ *
+ * @TODO
+ *
+ * @var array
+ */
+ protected $_params = array('amount' => 0,
+ 'radius' => 0,
+ 'threshold' => 0);
+
+ /**
+ * Apply the unsharp_mask effect.
+ *
+ * @return mixed true
+ */
+ public function apply()
+ {
+ $amount = $this->_params['amount'];
+ $radius = $this->_params['radius'];
+ $threshold = $this->_params['threshold'];
+
+ // Attempt to calibrate the parameters to Photoshop:
+ $amount = min($amount, 500);
+ $amount = $amount * 0.016;
+ if ($amount == 0) {
+ return true;
+ }
+
+ $radius = min($radius, 50);
+ $radius = $radius * 2;
+
+ $threshold = min($threshold, 255);
+
+ $radius = abs(round($radius)); // Only integers make sense.
+ if ($radius == 0) {
+ return true;
+ }
+
+ $img = $this->_image->_im;
+ $w = ImageSX($img);
+ $h = ImageSY($img);
+ $imgCanvas = ImageCreateTrueColor($w, $h);
+ $imgCanvas2 = ImageCreateTrueColor($w, $h);
+ $imgBlur = ImageCreateTrueColor($w, $h);
+ $imgBlur2 = ImageCreateTrueColor($w, $h);
+ ImageCopy($imgCanvas, $img, 0, 0, 0, 0, $w, $h);
+ ImageCopy($imgCanvas2, $img, 0, 0, 0, 0, $w, $h);
+
+ // Gaussian blur matrix:
+ //
+ // 1 2 1
+ // 2 4 2
+ // 1 2 1
+ //
+ //////////////////////////////////////////////////
+
+ // Move copies of the image around one pixel at the time and merge them with weight
+ // according to the matrix. The same matrix is simply repeated for higher radii.
+ for ($i = 0; $i < $radius; $i++) {
+ ImageCopy ($imgBlur, $imgCanvas, 0, 0, 1, 1, $w - 1, $h - 1); // up left
+ ImageCopyMerge($imgBlur, $imgCanvas, 1, 1, 0, 0, $w, $h, 50); // down right
+ ImageCopyMerge($imgBlur, $imgCanvas, 0, 1, 1, 0, $w - 1, $h, 33.33333); // down left
+ ImageCopyMerge($imgBlur, $imgCanvas, 1, 0, 0, 1, $w, $h - 1, 25); // up right
+ ImageCopyMerge($imgBlur, $imgCanvas, 0, 0, 1, 0, $w - 1, $h, 33.33333); // left
+ ImageCopyMerge($imgBlur, $imgCanvas, 1, 0, 0, 0, $w, $h, 25); // right
+ ImageCopyMerge($imgBlur, $imgCanvas, 0, 0, 0, 1, $w, $h - 1, 20 ); // up
+ ImageCopyMerge($imgBlur, $imgCanvas, 0, 1, 0, 0, $w, $h, 16.666667); // down
+ ImageCopyMerge($imgBlur, $imgCanvas, 0, 0, 0, 0, $w, $h, 50); // center
+ ImageCopy ($imgCanvas, $imgBlur, 0, 0, 0, 0, $w, $h);
+
+ // During the loop above the blurred copy darkens, possibly due to a roundoff
+ // error. Therefore the sharp picture has to go through the same loop to
+ // produce a similar image for comparison. This is not a good thing, as processing
+ // time increases heavily.
+ ImageCopy ($imgBlur2, $imgCanvas2, 0, 0, 0, 0, $w, $h);
+ ImageCopyMerge($imgBlur2, $imgCanvas2, 0, 0, 0, 0, $w, $h, 50);
+ ImageCopyMerge($imgBlur2, $imgCanvas2, 0, 0, 0, 0, $w, $h, 33.33333);
+ ImageCopyMerge($imgBlur2, $imgCanvas2, 0, 0, 0, 0, $w, $h, 25);
+ ImageCopyMerge($imgBlur2, $imgCanvas2, 0, 0, 0, 0, $w, $h, 33.33333);
+ ImageCopyMerge($imgBlur2, $imgCanvas2, 0, 0, 0, 0, $w, $h, 25);
+ ImageCopyMerge($imgBlur2, $imgCanvas2, 0, 0, 0, 0, $w, $h, 20 );
+ ImageCopyMerge($imgBlur2, $imgCanvas2, 0, 0, 0, 0, $w, $h, 16.666667);
+ ImageCopyMerge($imgBlur2, $imgCanvas2, 0, 0, 0, 0, $w, $h, 50);
+ ImageCopy ($imgCanvas2, $imgBlur2, 0, 0, 0, 0, $w, $h);
+ }
+
+ // Calculate the difference between the blurred pixels and the original
+ // and set the pixels
+ for ($x = 0; $x < $w; $x++) { // each row
+ for ($y = 0; $y < $h; $y++) { // each pixel
+
+ $rgbOrig = ImageColorAt($imgCanvas2, $x, $y);
+ $rOrig = (($rgbOrig >> 16) & 0xFF);
+ $gOrig = (($rgbOrig >> 8) & 0xFF);
+ $bOrig = ($rgbOrig & 0xFF);
+
+ $rgbBlur = ImageColorAt($imgCanvas, $x, $y);
+ $rBlur = (($rgbBlur >> 16) & 0xFF);
+ $gBlur = (($rgbBlur >> 8) & 0xFF);
+ $bBlur = ($rgbBlur & 0xFF);
+
+ // When the masked pixels differ less from the original
+ // than the threshold specifies, they are set to their original value.
+ $rNew = (abs($rOrig - $rBlur) >= $threshold) ? max(0, min(255, ($amount * ($rOrig - $rBlur)) + $rOrig)) : $rOrig;
+ $gNew = (abs($gOrig - $gBlur) >= $threshold) ? max(0, min(255, ($amount * ($gOrig - $gBlur)) + $gOrig)) : $gOrig;
+ $bNew = (abs($bOrig - $bBlur) >= $threshold) ? max(0, min(255, ($amount * ($bOrig - $bBlur)) + $bOrig)) : $bOrig;
+
+ if (($rOrig != $rNew) || ($gOrig != $gNew) || ($bOrig != $bNew)) {
+ $pixCol = ImageColorAllocate($img, $rNew, $gNew, $bNew);
+ ImageSetPixel($img, $x, $y, $pixCol);
+ }
+ }
+ }
+ ImageDestroy($imgCanvas);
+ ImageDestroy($imgCanvas2);
+ ImageDestroy($imgBlur);
+ ImageDestroy($imgBlur2);
+
+ return true;
+ }
+
+}
projects / horde.git / commitdiff