/**
* Executes the auto-crop operation on the $img
*
* @param WideImage_Image $img
* @param int $rgb_threshold The difference in RGB from $base_color
* @param int $pixel_cutoff The number of pixels on each border that must be over $rgb_threshold
* @param int $base_color The color that will get cropped
* @return WideImage_Image resulting auto-cropped image
*/
function execute($img, $margin, $rgb_threshold, $pixel_cutoff, $base_color)
{
$margin = intval($margin);
$rgb_threshold = intval($rgb_threshold);
if ($rgb_threshold < 0) {
$rgb_threshold = 0;
}
$pixel_cutoff = intval($pixel_cutoff);
if ($pixel_cutoff <= 1) {
$pixel_cutoff = 1;
}
if ($base_color === null) {
$rgb_base = $img->getRGBAt(0, 0);
} else {
if ($base_color < 0) {
return $img->copy();
}
$rgb_base = $img->getColorRGB($base_color);
}
$cut_rect = array('left' => 0, 'top' => 0, 'right' => $img->getWidth() - 1, 'bottom' => $img->getHeight() - 1);
for ($y = 0; $y <= $cut_rect['bottom']; $y++) {
$count = 0;
for ($x = 0; $x <= $cut_rect['right']; $x++) {
$rgb = $img->getRGBAt($x, $y);
$diff = abs($rgb['red'] - $rgb_base['red']) + abs($rgb['green'] - $rgb_base['green']) + abs($rgb['blue'] - $rgb_base['blue']);
if ($diff > $rgb_threshold) {
$count++;
if ($count >= $pixel_cutoff) {
$cut_rect['top'] = $y;
break 2;
}
}
}
}
for ($y = $img->getHeight() - 1; $y >= $cut_rect['top']; $y--) {
$count = 0;
for ($x = 0; $x <= $cut_rect['right']; $x++) {
$rgb = $img->getRGBAt($x, $y);
$diff = abs($rgb['red'] - $rgb_base['red']) + abs($rgb['green'] - $rgb_base['green']) + abs($rgb['blue'] - $rgb_base['blue']);
if ($diff > $rgb_threshold) {
$count++;
if ($count >= $pixel_cutoff) {
$cut_rect['bottom'] = $y;
break 2;
}
}
}
}
for ($x = 0; $x <= $cut_rect['right']; $x++) {
$count = 0;
for ($y = $cut_rect['top']; $y <= $cut_rect['bottom']; $y++) {
$rgb = $img->getRGBAt($x, $y);
$diff = abs($rgb['red'] - $rgb_base['red']) + abs($rgb['green'] - $rgb_base['green']) + abs($rgb['blue'] - $rgb_base['blue']);
if ($diff > $rgb_threshold) {
$count++;
if ($count >= $pixel_cutoff) {
$cut_rect['left'] = $x;
break 2;
}
}
}
}
for ($x = $cut_rect['right']; $x >= $cut_rect['left']; $x--) {
$count = 0;
for ($y = $cut_rect['top']; $y <= $cut_rect['bottom']; $y++) {
$rgb = $img->getRGBAt($x, $y);
$diff = abs($rgb['red'] - $rgb_base['red']) + abs($rgb['green'] - $rgb_base['green']) + abs($rgb['blue'] - $rgb_base['blue']);
if ($diff > $rgb_threshold) {
$count++;
if ($count >= $pixel_cutoff) {
$cut_rect['right'] = $x;
break 2;
}
}
}
}
$cut_rect = array('left' => $cut_rect['left'] - $margin, 'top' => $cut_rect['top'] - $margin, 'right' => $cut_rect['right'] + $margin, 'bottom' => $cut_rect['bottom'] + $margin);
if ($cut_rect['left'] < 0) {
$cut_rect['left'] = 0;
}
if ($cut_rect['top'] < 0) {
$cut_rect['top'] = 0;
}
if ($cut_rect['right'] >= $img->getWidth()) {
$cut_rect['right'] = $img->getWidth() - 1;
}
if ($cut_rect['bottom'] >= $img->getHeight()) {
$cut_rect['bottom'] = $img->getHeight() - 1;
}
return $img->crop($cut_rect['left'], $cut_rect['top'], $cut_rect['right'] - $cut_rect['left'] + 1, $cut_rect['bottom'] - $cut_rect['top'] + 1);
}
