Component-Builder/admin/compiler/joomla_3/wideimage/Operation/Unsharp.php

136 lines
4.1 KiB
PHP
Raw Normal View History

2016-01-30 20:28:43 +00:00
<?php
/**
* @author Gasper Kozak
* @copyright 2007-2011
This file is part of WideImage.
WideImage is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
WideImage is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with WideImage; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
* @package Internal/Operations
**/
/**
* Unsharp filter
*
* This filter was taken from http://vikjavev.no/computing/ump.php,
* the original author Torstein Hønsi. Adapted to fit better within
* the Wideimage package.
*
* @package Internal/Operations
*/
class WideImage_Operation_Unsharp {
/**
* Returns sharpened image
*
* @param WideImage_Image $image
* @param float $amount
* @param int $radius
* @param float $threshold
* @return WideImage_Image
*/
function execute($image, $amount, $radius, $threshold) {
// Attempt to calibrate the parameters to Photoshop:
if ($amount > 500) $amount = 500;
$amount = $amount * 0.016;
if ($radius > 50) $radius = 50;
$radius = $radius * 2;
if ($threshold > 255) $threshold = 255;
$radius = abs(round($radius)); // Only integers make sense.
if ($radius == 0) {
return $image;
}
// Gaussian blur matrix
$matrix = array(
array(1, 2, 1),
array(2, 4, 2),
array(1, 2, 1)
);
$blurred = $image->applyConvolution($matrix, 16, 0);
if($threshold > 0) {
// Calculate the difference between the blurred pixels and the original
// and set the pixels
for ($x = 0; $x < $image->getWidth(); $x++) {
for ($y = 0; $y < $image->getHeight(); $y++) {
$rgbOrig = $image->getRGBAt($x, $y);
$rOrig = $rgbOrig["red"];
$gOrig = $rgbOrig["green"];
$bOrig = $rgbOrig["blue"];
$rgbBlur = $blurred->getRGBAt($x, $y);
$rBlur = $rgbBlur["red"];
$gBlur = $rgbBlur["green"];
$bBlur = $rgbBlur["blue"];
// 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;
$rgbNew = array("red" => $rNew, "green" => $gNew, "blue" => $bNew, "alpha" => 0);
if (($rOrig != $rNew) || ($gOrig != $gNew) || ($bOrig != $bNew)) {
$image->setRGBAt($x, $y, $rgbNew);
}
}
}
}
else {
$w = $image->getWidth();
$h = $image->getHeight();
for ($x = 0; $x < $w; $x++) {
for ($y = 0; $y < $h; $y++) {
$rgbOrig = $image->getRGBAt($x, $y);
$rOrig = $rgbOrig["red"];
$gOrig = $rgbOrig["green"];
$bOrig = $rgbOrig["blue"];
$rgbBlur = $blurred->getRGBAt($x, $y);
$rBlur = $rgbBlur["red"];
$gBlur = $rgbBlur["green"];
$bBlur = $rgbBlur["blue"];
$rNew = ($amount * ($rOrig - $rBlur)) + $rOrig;
if($rNew>255){$rNew=255;}
elseif($rNew<0){$rNew=0;}
$gNew = ($amount * ($gOrig - $gBlur)) + $gOrig;
if($gNew>255){$gNew=255;}
elseif($gNew<0){$gNew=0;}
$bNew = ($amount * ($bOrig - $bBlur)) + $bOrig;
if($bNew>255){$bNew=255;}
elseif($bNew<0){$bNew=0;}
$rgbNew = array("red" => $rNew, "green" => $gNew, "blue" => $bNew, "alpha" => 0);
$image->setRGBAt($x, $y, $rgbNew);
}
}
}
return $image;
}
}