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;
}

<?php
    $cool = imagecreatefrompng('imagefile.png');
    echo memory_get_usage(),'<br />';
 
      $timeparts = explode(' ',microtime());
  $starttime = $timeparts[1].substr($timeparts[0],1);
	  $cool = imagecreatefrompng('primespiral2000.png');
    //imagedestroy($cool);
    unset($cool);
      $timeparts = explode(' ',microtime());
  $endtime = $timeparts[1].substr($timeparts[0],1);
  echo bcsub($endtime,$starttime,6),'<br />';
    echo memory_get_usage(),'<br />';
    ?>

    $cool = imagecreatefrompng('imagefile.png');
    imagedestroy($cool);
echo isset($cool); //1
 $cool = imagecreatefrompng('imagefile.png');
    unset($cool);
echo isset($cool); //echos nothing...

ob_start();
include('GIFEncoder.class.php');
$board_width = 60;
$board_height = 60;
$pad_width = 5;
$pad_height = 15;
$ball_size = 5;
$game_width = $board_width - $pad_width*2 - $ball_size;
$game_height = $board_height-$ball_size;
 
 
//FIND ALL Points
//Initial point
 
$x = 0;
$y = rand(0,$game_height);
$xv = rand(1,10);
$yv = rand(1,10);
$pt[] = array($x,$y);
do{
	$x += $xv;
	$y += $yv;

include('GIFEncoder.class.php');
ob_start();
$msg = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890~!@#$%^&*()-_=+`[]{};:?/.,<>\\|"';
$length = strlen($msg);
$max_x = 400; //image x size
$max_y = 400; //image y size
$font_file = 'cour.ttf';//font, best monospace
$font_size = 10;//font site
$grid = 10;//gridient of the fonts
$measuer = imagettfbbox(10,0,$font_file,'1');
$space = 5;//space between letters
$char_height = $measuer[1] - $measuer[7] + $space;
$char_width = $measuer[2] - $measuer[0] + $space;
$i = 1;
$colorimage = imagecreatetruecolor(1,1);
$color[1] = imagecolorallocate($colorimage, 255, 255, 255);
while($i<$grid){
 
	$color[] = imagecolorallocate($colorimage, 0, 255-20*$i, 0);
	++$i;
}
imagedestroy($colorimage);
//ENOUGH TEXT TO FILL THE PAGE.
$width = ceil($max_x/$char_width);
$height = ceil($max_y/$char_height);
 
 
$x = 0;
while($x < $width){
	$y = 0;
	while($y < $height){
		$text[$x][$y] = $msg[rand(0,$length)];
		++$y;
	}
	$drop[$x] = rand(0, $width);
	++$x;
}
$i = 0;
while($i<$height+$grid){
	$image = imagecreatetruecolor($max_x, $max_y);
	$x = 0;
	while($x < $width){
		$y = 0;
 
		while($y < $drop[$x]){
			if($drop[$x]-$y<=$grid){
				imagettftext($image, $font_size, 0, $x*$char_width, ($y+1)*$char_height-$space, $color[$drop[$x]-$y], $font_file, $text[$x][$y]);
			}
			++$y;
		}
		if($drop[$x]<$height+$grid){
			++$drop[$x];
		}else{
			$drop[$x] = 0;
		}
		++$x;
	}
	imagegif($image);
	$imagedata[$i] = ob_get_contents();
	imagedestroy($image);
	ob_clean();
	++$i;
}
 
$gif = new GIFEncoder(
                            $imagedata,
                            100,
                            0,
                            2,
                            0, 0, 0,
                            "bin"
        ); 
Header ( 'Content-type:image/gif' );
echo    $gif->GetAnimation ();

include('GIFEncoder.class.php');
$max_x = 468;
$max_y = 60;
$step = 10;
$font_file = 'cour.ttf';
$font_size = 10;
$color = pow(255,2);