/**
  * Applies filter effects to the given image
  *
  * @param Image\Image $image The image to filter.
  *
  * @return Image\Image The filtered image.
  *
  * @throws FilterException if the image filter algorithm fails.
  */
 public function applyFilter(Image\Image $image)
 {
     if ($this->level <= 0) {
         $gd = $image->getCore();
         $width = imagesx($gd);
         $height = imagesy($gd);
         for ($x = 0; $x < $width; ++$x) {
             for ($y = 0; $y < $height; ++$y) {
                 $rgba = imagecolorsforindex($gd, imagecolorat($gd, $x, $y));
                 $r = $rgba['red'];
                 $g = $rgba['green'];
                 $b = $rgba['blue'];
                 $a = $rgba['alpha'];
                 $level = $this->level * -1;
                 $max = max($r, $g, $b);
                 $avg = ($r + $g + $b) / 3;
                 $amt = abs($max - $avg) * 2 / 255 * $level / 100;
                 if ($r !== $max) {
                     $r += ($max - $r) * $amt;
                 }
                 if ($g !== $max) {
                     $g += ($max - $g) * $amt;
                 }
                 if ($b !== $max) {
                     $b += ($max - $b) * $amt;
                 }
                 imagesetpixel($gd, $x, $y, imagecolorallocatealpha($gd, $r, $g, $b, $a));
             }
         }
         $image->setCore($gd);
     } else {
         $image->filter(new SaturateFilter($this->level));
     }
     return $image;
 }
 /**
  * Applies filter effects to the given image
  *
  * @param Image\Image $image The image to filter.
  *
  * @return Image\Image The filtered image.
  *
  * @throws FilterException if the image filter algorithm fails.
  */
 public function applyFilter(Image\Image $image)
 {
     // Change the level range from 0-200 to -100-100 to use it in the
     // brightness and contrast filters.
     $level = $this->level - 100;
     if ($level <= 0) {
         $image->filter(new BrightnessFilter($level));
     } else {
         // Don't apply a ridiculous amount of brightness or contrast;
         // exposure level 0-100 applies 0%-15% of contrast and brightness.
         $level = (int) round($level / 100 * 15);
         $image->filter(new BrightnessFilter($level));
         $image->filter(new ContrastFilter($level));
     }
     return $image;
 }