damgen.php

<?php
class PWImage {

    //instantiate class
    //$filename : the path+filename of the written png file
    //$string   : the text that you want to have in the image
    //$fact     : a magnification factor. play with values>2
    //$bcol     : the background colour, R, G, B (0-255)
    //$fcol     : the foreground colour, R, G, B (0-255)
    function PWImage($filename, $string, $fact, $bcol, $fcol) {
        $font = 5;
        $cosrate = rand(10,19);
        $sinrate = rand(10,18);
       
        $charwidth = imagefontwidth($font);
        $charheight = imagefontheight($font);
        $width=(strlen($string)+2)*$charwidth;
        $height=2*$charheight;

        $im = @imagecreatetruecolor($width, $height) or die("Cannot Initialize new GD image stream");
        $im2 = imagecreatetruecolor($width*$fact, $height*$fact);
        $bcol = imagecolorallocate($im, $bcol[0], $bcol[1], $bcol[2]);
        $fcol = imagecolorallocate($im, $fcol[0], $fcol[1], $fcol[2]);

        imagefill($im, 0, 0, $bcol);
        imagefill($im2, 0, 0, $bcol);

        $dotcol = imagecolorallocate($im, (abs($this->getR($fcol)-$this->getR($bcol)))/2.5,
                                          (abs($this->getG($fcol)-$this->getG($bcol)))/2.5,
                                          (abs($this->getB($fcol)-$this->getB($bcol)))/2.5);

        $dotcol2 = imagecolorallocate($im, (abs($this->getR($fcol)-$this->getR($bcol)))/1.5,
                                           (abs($this->getG($fcol)-$this->getG($bcol)))/1.5,
                                           (abs($this->getB($fcol)-$this->getB($bcol)))/3.5);

        $linecol = imagecolorallocate($im, (abs($this->getR($fcol)-$this->getR($bcol)))/2.4,
                                           (abs($this->getG($fcol)-$this->getG($bcol)))/2.1,
                                           (abs($this->getB($fcol)-$this->getB($bcol)))/2.5);

        for($i=0; $i<$width; $i=$i+rand(1,5)) {
            for($j=0; $j<$height; $j=$j+rand(1,5)) {
                imagesetpixel($im, $i, $j, $dotcol);
            }
        }

        imagestring($im, $font, $charwidth, $charheight/2, $string, $fcol);

        for($j=0; $j<$height*$fact; $j=$j+rand(3,6)) {
            imageline($im2, 0, $j, $width*$fact, $j, $linecol);
        }

        for($i=0; $i<$width*$fact; $i=$i+rand(4,9)) {
            imageline($im2, $i, 0, $i, $height*$fact, $linecol);
        }

        for($i=0; $i<$width*$fact; $i++) {
            for($j=0; $j<$height*$fact; $j++) {
            $x = abs(((cos($i/$cosrate)*5+sin($j/$sinrate*2)*2+$i)/$fact))%$width;
                $y = abs(((sin($j/$sinrate)*5+cos($i/$cosrate*2)*2+$j)/$fact))%$height;
                $col = imagecolorat($im, $x, $y);
                if ($col!=$bcol) imagesetpixel($im2, $i, $j, $col);
            }
        }
   
        for($j=0; $j<$height*$fact; $j=$j+rand(1,5)) {
            for($i=0; $i<$width*$fact; $i=$i+rand(1,5)) {
                imagesetpixel($im2, $i, $j, $dotcol2);
            }
        }

        ob_start();
        imagepng($im2);
        $buffer = ob_get_contents();
        ob_end_clean();
        $handle = fopen($filename, "w");
        fwrite($handle, $buffer);
        fclose($handle);

        imagedestroy($im);
        imagedestroy($im2);
    }
   
    //functions to extract RGB values from combined 24bit color value
    function getR($col) {return (($col >> 8) >> 8) % 256;}
    function getG($col) {return ($col >> 8) % 256;}
    function getB($col) {return $col % 256;}

}   

//**********************************************
//*************** example use ******************
//**********************************************

$grab="Starfish";

$pw = new PWImage("temp1.png", $grab, 2, array(0, 0, 0), array(255, 128, 200));
$pw = new PWImage("temp2.png", sha1($grab), 2, array(255, 255, 255), array(0, 0, 0));
$pw = new PWImage("temp3.png", md5($grab), 2, array(0, 0, 0), array(255, 228, 250));
$pw = new PWImage("temp4.png", crypt($grab), 2, array(0, 0, 0), array(0, 255, 255));

echo "<img src='temp1.png'/><br/><img src='temp2.png'/><br/><img src='temp3.png'/><br/><img src='temp4.png'/><br/>";

?>