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imagefilter function for PHP user without bundled GD

Sat, 03/03/2007 - 00:37 | by Mgccl

Imagefilter() have many powerful usages, like turn a image grayscale or do some blur actions. The small note at the bottom of the manual usually will make you want to say something negative about your hosting.

Note: This function is only available if PHP is compiled with the bundled version of the GD library.

Again, I will save you!
After the replication of imageconvolution function, the real useful tool not offered in non-bundled GD, imagefilter(), became my next victim. So here you have it, this function requires imageconvolution function and works almost(no error reporting) completely the same as the imagefilter function in PHP.net.

//include this file whenever you have to use imageconvolution...
//you can use in your project, but keep the comment below :)
//great for any image manipulation library
//Made by Chao Xu(Mgccl) 3/1/07
//www.webdevlogs.com
//V 1.0
if(!function_exists('imagefilter')){
	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;
	   }
	}
}

Tags:

Comments

by me (not verified) | Sat, 03/03/2007 - 23:13
Anonymous's picture

hi, thanks for the great

hi,

thanks for the great function! it's very useful for me :)

by Mgccl | Sat, 03/03/2007 - 23:19
Mgccl's picture

Wow, I thought no one will

Wow, I thought no one will ever really need this thing because it's so slow compare to the PHP version :Shock:
Thanks, because when I first released it, people think I got a "I don't care what I code! I have to do some coding or I will die!" problem

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