Home > PHP > again php captcha script

again php captcha script

You’ve already seen a post about captcha.If not i encourage you to see it.Thuough it is pretty simple captcha script.If you try to run that script you will notice that it is not like others where they have different type of background color,different type of font,noise.So in this post i will try to figure that.

First make a file name “captcha.php

now paste



function captcha($length) {

// generate a totally random string using md5
$rd = md5(rand(0, 999));

// We don't need a 32 character long string so we trim it down to 5 because md5 will return a long string
$code = substr($rd, 15, $length);

// Set the session to store the security code
$_SESSION["captcha"] = $code;

// Set the image width and height
$width = 200;
$height = 50;

// Create the image resource
$image = imagecreate($width, $height);

// Random RGB colours
$rgb1 = rand(0, 255);
$rgb2 = rand(0, 255);
$rgb3 = rand(0, 255);

$background = imagecolorallocate($image, $rgb1, $rgb2, $rgb3);
$text = imagecolorallocate($image, ($rgb1 - 60), ($rgb2 - 60), ($rgb3 - 60));

// Make the background colour
imagefill($image, 0, 0, $background);
for ($i = 0; $i < 10; $i++) {
$rx1 = rand(0,$width);
$rx2 = rand(0,$width);
$ry1 = rand(0,$height);
$ry2 = rand(0,$height);
$rcVal = rand(0,255);
$rc1 = imagecolorallocate($image,
//giving noise
imageline ($image, $rx1, $ry1, $rx2, $ry2, $rc1);

// Add randomly generated string in the image
for($i = 1; $i <= $length; $i++) {
$counter = rand(1, 2);

if ($counter == 1) {
$angle = rand(0, 45);
if ($counter == 2) {
$angle = rand(315, 360);

imagettftext($image, rand(14, 20), $angle, ($i * 25), 30, $text, "font/LucidaBrightDemiItalic.ttf", substr($code, ($i - 1), 1));

// Add a border
imagerectangle($image, 0, 0, $width - 1, $height - 1, $text);

// Tell the browser what kind of file is come in
header("Content-Type: image/png");

// Output the newly created image in jpeg format

// Free up resources


this code into that file.

You see “LucidaBrightDemiItalic.ttf”.I have this font in font directory.You can use ur font.And that will be your font style of captcha.But remember you have to put font file in the directory or Sub-directory where your php file will stay.

Now include this file in any other php file and make a call with


here 4 is the number of character you want to show.You can give your length of string.Here we use session to store the captcha string in $_SESSION global array.Since we have to use this later, to check whether the user submit the data or not.So that’s it.
And “Have a good programming

Categories: PHP
  1. No comments yet.
  1. No trackbacks yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: