/home/edulekha/studygroup.edulekha.com/ow_libraries/wideimage/Operation/AsNegative.php
<?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
**/
/**
* AsNegative operation class
*
* @package Internal/Operations
*/
class WideImage_Operation_AsNegative
{
/**
* Returns a greyscale copy of an image
*
* @param WideImage_Image $image
* @return WideImage_Image
*/
function execute($image)
{
$palette = !$image->isTrueColor();
$transparent = $image->isTransparent();
if ($palette && $transparent)
$tcrgb = $image->getTransparentColorRGB();
$new = $image->asTrueColor();
if (!imagefilter($new->getHandle(), IMG_FILTER_NEGATE))
throw new WideImage_GDFunctionResultException("imagefilter() returned false");
if ($palette)
{
$new = $new->asPalette();
if ($transparent)
{
$irgb = array('red' => 255 - $tcrgb['red'], 'green' => 255 - $tcrgb['green'], 'blue' => 255 - $tcrgb['blue'], 'alpha' => 127);
// needs imagecolorexactalpha instead of imagecolorexact, otherwise doesn't work on some transparent GIF images
$new_tci = imagecolorexactalpha($new->getHandle(), $irgb['red'], $irgb['green'], $irgb['blue'], 127);
$new->setTransparentColor($new_tci);
}
}
return $new;
}
}