function imageConvolution($src, $filter, $filter_div, $offset)
{
if ($src == NULL) {
return 0;
}
$sx = imagesx($src);
$sy = imagesy($src);
$srcback = ImageCreateTrueColor($sx, $sy);
ImageAlphaBlending($srcback, false);
ImageAlphaBlending($src, false);
ImageCopy($srcback, $src, 0, 0, 0, 0, $sx, $sy);
if ($srcback == NULL) {
return 0;
}
for ($y = 0; $y < $sy; ++$y) {
for ($x = 0; $x < $sx; ++$x) {
$new_r = $new_g = $new_b = 0;
$alpha = imagecolorat($srcback, @$pxl[0], @$pxl[1]);
$new_a = $alpha >> 24;
for ($j = 0; $j < 3; ++$j) {
$yv = min(max($y - 1 + $j, 0), $sy - 1);
for ($i = 0; $i < 3; ++$i) {
$pxl = array(min(max($x - 1 + $i, 0), $sx - 1), $yv);
$rgb = imagecolorat($srcback, $pxl[0], $pxl[1]);
$new_r += ($rgb >> 16 & 0xff) * $filter[$j][$i];
$new_g += ($rgb >> 8 & 0xff) * $filter[$j][$i];
$new_b += ($rgb & 0xff) * $filter[$j][$i];
$new_a += ((0x7f000000 & $rgb) >> 24) * $filter[$j][$i];
}
}
$new_r = $new_r / $filter_div + $offset;
$new_g = $new_g / $filter_div + $offset;
$new_b = $new_b / $filter_div + $offset;
$new_a = $new_a / $filter_div + $offset;
$new_r = $new_r > 255 ? 255 : ($new_r < 0 ? 0 : $new_r);
$new_g = $new_g > 255 ? 255 : ($new_g < 0 ? 0 : $new_g);
$new_b = $new_b > 255 ? 255 : ($new_b < 0 ? 0 : $new_b);
$new_a = $new_a > 127 ? 127 : ($new_a < 0 ? 0 : $new_a);
$new_pxl = ImageColorAllocateAlpha($src, (int) $new_r, (int) $new_g, (int) $new_b, $new_a);
if ($new_pxl == -1) {
$new_pxl = ImageColorClosestAlpha($src, (int) $new_r, (int) $new_g, (int) $new_b, $new_a);
}
if ($y >= 0 && $y < $sy) {
imagesetpixel($src, $x, $y, $new_pxl);
}
}
}
imagedestroy($srcback);
return 1;
}
protected function imageconvolution($src, $filter, $filter_div, $offset)
{
if ($src == NULL) {
return 0;
}
$sx = imagesx($src);
$sy = imagesy($src);
$srcback = ImageCreateTrueColor($sx, $sy);
ImageCopy($srcback, $src, 0, 0, 0, 0, $sx, $sy);
if ($srcback == NULL) {
return 0;
}
#FIX HERE
#$pxl array was the problem so simply set it with very low values
$pxl = array(1, 1);
#this little fix worked for me as the undefined array threw out errors
for ($y = 0; $y < $sy; ++$y) {
for ($x = 0; $x < $sx; ++$x) {
$new_r = $new_g = $new_b = 0;
$alpha = imagecolorat($srcback, $pxl[0], $pxl[1]);
$new_a = $alpha >> 24;
for ($j = 0; $j < 3; ++$j) {
$yv = min(max($y - 1 + $j, 0), $sy - 1);
for ($i = 0; $i < 3; ++$i) {
$pxl = array(min(max($x - 1 + $i, 0), $sx - 1), $yv);
$rgb = imagecolorat($srcback, $pxl[0], $pxl[1]);
$new_r += ($rgb >> 16 & 0xff) * $filter[$j][$i];
$new_g += ($rgb >> 8 & 0xff) * $filter[$j][$i];
$new_b += ($rgb & 0xff) * $filter[$j][$i];
}
}
$new_r = $new_r / $filter_div + $offset;
$new_g = $new_g / $filter_div + $offset;
$new_b = $new_b / $filter_div + $offset;
$new_r = $new_r > 255 ? 255 : ($new_r < 0 ? 0 : $new_r);
$new_g = $new_g > 255 ? 255 : ($new_g < 0 ? 0 : $new_g);
$new_b = $new_b > 255 ? 255 : ($new_b < 0 ? 0 : $new_b);
$new_pxl = ImageColorAllocateAlpha($src, (int) $new_r, (int) $new_g, (int) $new_b, $new_a);
if ($new_pxl == -1) {
$new_pxl = ImageColorClosestAlpha($src, (int) $new_r, (int) $new_g, (int) $new_b, $new_a);
}
if ($y >= 0 && $y < $sy) {
imagesetpixel($src, $x, $y, $new_pxl);
}
}
}
imagedestroy($srcback);
return 1;
}
function imagefilter($source, $var, $arg1 = null, $arg2 = null, $arg3 = null)
{
#define('IMAGE_FILTER_NEGATE',0);
#define('IMAGE_FILTER_GRAYSCALE',0);
#define('IMAGE_FILTER_BRIGHTNESS',2);
#define('IMAGE_FILTER_CONTRAST',3);
#define('IMAGE_FILTER_COLORIZE',4);
#define('IMAGE_FILTER_EDGEDETECT',5);
#define('IMAGE_FILTER_EMBOSS',6);
#define('IMAGE_FILTER_GAUSSIAN_BLUR',7);
#define('IMAGE_FILTER_SELECTIVE_BLUR',8);
#define('IMAGE_FILTER_MEAN_REMOVAL',9);
#define('IMAGE_FILTER_SMOOTH',10);
$max_y = imagesy($source);
$max_x = imagesx($source);
switch ($var) {
case 0:
$y = 0;
while ($y < $max_y) {
$x = 0;
while ($x < $max_x) {
$rgb = imagecolorat($source, $x, $y);
$r = 255 - ($rgb >> 16 & 0xff);
$g = 255 - ($rgb >> 8 & 0xff);
$b = 255 - ($rgb & 0xff);
$a = $rgb >> 24;
$new_pxl = imagecolorallocatealpha($source, $r, $g, $b, $a);
if ($new_pxl == false) {
$new_pxl = imagecolorclosestalpha($source, $r, $g, $b, $a);
}
imagesetpixel($source, $x, $y, $new_pxl);
++$x;
}
++$y;
}
return true;
break;
case 1:
$y = 0;
while ($y < $max_y) {
$x = 0;
while ($x < $max_x) {
$rgb = imagecolorat($source, $x, $y);
$a = $rgb >> 24;
$r = ($rgb >> 16 & 0xff) * 0.299 + ($rgb >> 8 & 0xff) * 0.587 + ($rgb & 0xff) * 0.114;
$new_pxl = imagecolorallocatealpha($source, $r, $r, $r, $a);
if ($new_pxl == false) {
$new_pxl = imagecolorclosestalpha($source, $r, $r, $r, $a);
}
imagesetpixel($source, $x, $y, $new_pxl);
++$x;
}
++$y;
}
return true;
break;
case 2:
$y = 0;
while ($y < $max_y) {
$x = 0;
while ($x < $max_x) {
$rgb = imagecolorat($source, $x, $y);
$r = ($rgb >> 16 & 0xff) + $arg1;
$g = ($rgb >> 8 & 0xff) + $arg1;
$b = ($rgb & 0xff) + $arg1;
$a = $rgb >> 24;
$r = $r > 255 ? 255 : ($r < 0 ? 0 : $r);
$g = $g > 255 ? 255 : ($g < 0 ? 0 : $g);
$b = $b > 255 ? 255 : ($b < 0 ? 0 : $b);
$new_pxl = imagecolorallocatealpha($source, $r, $g, $b, $a);
if ($new_pxl == false) {
$new_pxl = imagecolorclosestalpha($source, $r, $g, $b, $a);
}
imagesetpixel($source, $x, $y, $new_pxl);
++$x;
}
++$y;
}
return true;
break;
case 3:
$contrast = pow((100 - $arg1) / 100, 2);
$y = 0;
while ($y < $max_y) {
$x = 0;
while ($x < $max_x) {
$rgb = imagecolorat($source, $x, $y);
$a = $rgb >> 24;
$r = ((($rgb >> 16 & 0xff) / 255 - 0.5) * $contrast + 0.5) * 255;
$g = ((($rgb >> 8 & 0xff) / 255 - 0.5) * $contrast + 0.5) * 255;
$b = ((($rgb & 0xff) / 255 - 0.5) * $contrast + 0.5) * 255;
$r = $r > 255 ? 255 : ($r < 0 ? 0 : $r);
$g = $g > 255 ? 255 : ($g < 0 ? 0 : $g);
$b = $b > 255 ? 255 : ($b < 0 ? 0 : $b);
$new_pxl = imagecolorallocatealpha($source, $r, $g, $b, $a);
if ($new_pxl == false) {
$new_pxl = imagecolorclosestalpha($source, $r, $g, $b, $a);
}
imagesetpixel($source, $x, $y, $new_pxl);
++$x;
}
++$y;
}
return true;
break;
case 4:
$x = 0;
while ($x < $max_x) {
$y = 0;
while ($y < $max_y) {
$rgb = imagecolorat($source, $x, $y);
$r = ($rgb >> 16 & 0xff) + $arg1;
$g = ($rgb >> 8 & 0xff) + $arg2;
$b = ($rgb & 0xff) + $arg3;
$a = $rgb >> 24;
$r = $r > 255 ? 255 : ($r < 0 ? 0 : $r);
$g = $g > 255 ? 255 : ($g < 0 ? 0 : $g);
$b = $b > 255 ? 255 : ($b < 0 ? 0 : $b);
$new_pxl = imagecolorallocatealpha($source, $r, $g, $b, $a);
if ($new_pxl == false) {
$new_pxl = imagecolorclosestalpha($source, $r, $g, $b, $a);
}
imagesetpixel($source, $x, $y, $new_pxl);
++$y;
}
++$x;
}
return true;
break;
case 5:
return imageconvolution($source, array(array(-1, 0, -1), array(0, 4, 0), array(-1, 0, -1)), 1, 127);
break;
case 6:
return imageconvolution($source, array(array(1.5, 0, 0), array(0, 0, 0), array(0, 0, -1.5)), 1, 127);
break;
case 7:
return imageconvolution($source, array(array(1, 2, 1), array(2, 4, 2), array(1, 2, 1)), 16, 0);
break;
case 8:
for ($y = 0; $y < $max_y; $y++) {
for ($x = 0; $x < $max_x; $x++) {
$flt_r_sum = $flt_g_sum = $flt_b_sum = 0;
$cpxl = imagecolorat($source, $x, $y);
for ($j = 0; $j < 3; $j++) {
for ($i = 0; $i < 3; $i++) {
if ($j == 1 && $i == 1) {
$flt_r[1][1] = $flt_g[1][1] = $flt_b[1][1] = 0.5;
} else {
$pxl = imagecolorat($source, $x - (3 >> 1) + $i, $y - (3 >> 1) + $j);
$new_a = $pxl >> 24;
//$r = (($pxl >> 16) & 0xFF);
//$g = (($pxl >> 8) & 0xFF);
//$b = ($pxl & 0xFF);
$new_r = abs(($cpxl >> 16 & 0xff) - ($pxl >> 16 & 0xff));
if ($new_r != 0) {
$flt_r[$j][$i] = 1 / $new_r;
} else {
$flt_r[$j][$i] = 1;
}
$new_g = abs(($cpxl >> 8 & 0xff) - ($pxl >> 8 & 0xff));
if ($new_g != 0) {
$flt_g[$j][$i] = 1 / $new_g;
} else {
$flt_g[$j][$i] = 1;
}
$new_b = abs(($cpxl & 0xff) - ($pxl & 0xff));
if ($new_b != 0) {
$flt_b[$j][$i] = 1 / $new_b;
} else {
$flt_b[$j][$i] = 1;
}
}
$flt_r_sum += $flt_r[$j][$i];
$flt_g_sum += $flt_g[$j][$i];
$flt_b_sum += $flt_b[$j][$i];
}
}
for ($j = 0; $j < 3; $j++) {
for ($i = 0; $i < 3; $i++) {
if ($flt_r_sum != 0) {
$flt_r[$j][$i] /= $flt_r_sum;
}
if ($flt_g_sum != 0) {
$flt_g[$j][$i] /= $flt_g_sum;
}
if ($flt_b_sum != 0) {
$flt_b[$j][$i] /= $flt_b_sum;
}
}
}
$new_r = $new_g = $new_b = 0;
for ($j = 0; $j < 3; $j++) {
for ($i = 0; $i < 3; $i++) {
$pxl = imagecolorat($source, $x - (3 >> 1) + $i, $y - (3 >> 1) + $j);
$new_r += ($pxl >> 16 & 0xff) * $flt_r[$j][$i];
$new_g += ($pxl >> 8 & 0xff) * $flt_g[$j][$i];
$new_b += ($pxl & 0xff) * $flt_b[$j][$i];
}
}
$new_r = $new_r > 255 ? 255 : ($new_r < 0 ? 0 : $new_r);
$new_g = $new_g > 255 ? 255 : ($new_g < 0 ? 0 : $new_g);
$new_b = $new_b > 255 ? 255 : ($new_b < 0 ? 0 : $new_b);
$new_pxl = ImageColorAllocateAlpha($source, (int) $new_r, (int) $new_g, (int) $new_b, $new_a);
if ($new_pxl == false) {
$new_pxl = ImageColorClosestAlpha($source, (int) $new_r, (int) $new_g, (int) $new_b, $new_a);
}
imagesetpixel($source, $x, $y, $new_pxl);
}
}
return true;
break;
case 9:
return imageconvolution($source, array(array(-1, -1, -1), array(-1, 9, -1), array(-1, -1, -1)), 1, 0);
break;
case 10:
return imageconvolution($source, array(array(1, 1, 1), array(1, $arg1, 1), array(1, 1, 1)), $arg1 + 8, 0);
break;
}
}
