Simple PHP Captcha Image Verification or Validation

Hello guys, This is yet another tutorial for creating captcha  Image Verification or Validation using simple php script.
And here goes the script

The below script is captcha.php

<?php

session_start();

$strlength = rand(4,7);

function createRandomString() {

$chars = “abcdefghijkmnopqrstuvwxyz023456789″;

srand((double)microtime()*1000000);

$i = 0;

$pass = ” ;

while ($i <= 7) {

$num = rand() % 33;

$tmp = substr($chars, $num, 1);

$pass = $pass . $tmp;

$i++;

}

return $pass;

}

$captchastr = strtoupper(createRandomString());

$randcolR = rand(100,230);

$randcolG = rand(100,230);

$randcolB = rand(100,230);

//initialize image $captcha is handle dimensions 200,50

$captcha = imageCreate(200,50);

$backcolor = imageColorAllocate($captcha, $randcolR, $randcolG, $randcolB);

$txtcolor = imageColorAllocate($captcha, ($randcolR - 30), ($randcolG - 30), ($randcolB - 30));

for($i=1;$i<=$strlength;$i++)

{

$clockorcounter = rand(1,2);

if ($clockorcounter == 1)

{

$rotangle = rand(0,45);

}

if ($clockorcounter == 2)

{

$rotangle = rand(315,360);

}

//$i*25 spaces the characters 25 pixels apart

imagettftext($captcha,rand(14,20),$rotangle,($i*25),30,$txtcolor,”/arial.ttf”,substr($captchastr,($i-1),1));

}

for($i=1; $i<=4;$i++)

{

imageellipse($captcha,rand(1,200),rand(1,50),rand(50,100),rand(12,25),$txtcolor);

}

for($i=1; $i<=4;$i++)

{

imageellipse($captcha,rand(1,200),rand(1,50),rand(50,100),rand(12,25),$backcolor);

}

//Send the headers (at last possible time)

header(’Content-type: image/png’);

//Output the image as a PNG

imagePNG($captcha);

//Delete the image from memory

imageDestroy($captcha);

$_SESSION[captchastr] = $captchastr;

?>
How to add this on your form ?

just add this HTML code <img src=”captcha.php”><input type=”text“ name=”captcha“>

Just keep the font in the same path where the captcha.php is placed,  download the FONT  arial.ttf

Thats all simple thanks guys.