In this post, I cover the PHP code for creating captcha code to be stored in a session variable. I start the session to store the captcha which is dynamically created using the PHP rand() function. I have created an image target layer and write the random code. This JPEG captcha image will be shown in the contact form. like this image.
This 'captcha.php' file Joint function.
PHP code to Create CAPTCHA
This 'phptextClass.php' file create captcha cade.
class phptextClass
{
public function phptext($text,$textColor,$backgroundColor='',$fontSize,$imgWidth,$imgHeight,$dir,$fileName)
{
/* settings */
$font = './calibri.ttf';/*define font*/
$textColor=$this->hexToRGB($textColor);
$im = imagecreatetruecolor($imgWidth, $imgHeight);
$textColor = imagecolorallocate($im, $textColor['r'],$textColor['g'],$textColor['b']);
if($backgroundColor==''){/*select random color*/
$colorCode=array('#56aad8', '#61c4a8', '#d3ab92');
$backgroundColor = $this->hexToRGB($colorCode[rand(0, count($colorCode)-1)]);
$backgroundColor = imagecolorallocate($im, $backgroundColor['r'],$backgroundColor['g'],$backgroundColor['b']);
}else{/*select background color as provided*/
$backgroundColor = $this->hexToRGB($backgroundColor);
$backgroundColor = imagecolorallocate($im, $backgroundColor['r'],$backgroundColor['g'],$backgroundColor['b']);
}
imagefill($im,0,0,$backgroundColor);
list($x, $y) = $this->ImageTTFCenter($im, $text, $font, $fontSize);
imagettftext($im, $fontSize, 0, $x, $y, $textColor, $font, $text);
if(imagejpeg($im,$dir.$fileName,90)){/*save image as JPG*/
return json_encode(array('status'=>TRUE,'image'=>$dir.$fileName));
imagedestroy($im);
}
}
public function phpcaptcha($textColor,$backgroundColor,$imgWidth,$imgHeight,$noiceLines=0,$noiceDots=0,$noiceColor='#162453')
{
/* Settings */
$text=$this->random();
$font = './font/monofont.ttf';/* font */
$textColor=$this->hexToRGB($textColor);
$fontSize = $imgHeight * 0.75;
$im = imagecreatetruecolor($imgWidth, $imgHeight);
$textColor = imagecolorallocate($im, $textColor['r'],$textColor['g'],$textColor['b']);
$backgroundColor = $this->hexToRGB($backgroundColor);
$backgroundColor = imagecolorallocate($im, $backgroundColor['r'],$backgroundColor['g'],$backgroundColor['b']);
/* generating lines randomly in background of image */
if($noiceLines>0){
$noiceColor=$this->hexToRGB($noiceColor);
$noiceColor = imagecolorallocate($im, $noiceColor['r'],$noiceColor['g'],$noiceColor['b']);
for( $i=0; $i<$noiceLines; $i++ ) {
imageline($im, mt_rand(0,$imgWidth), mt_rand(0,$imgHeight),
mt_rand(0,$imgWidth), mt_rand(0,$imgHeight), $noiceColor);
}}
if($noiceDots>0){/* generating the dots randomly in background */
for( $i=0; $i<$noiceDots; $i++ ) {
imagefilledellipse($im, mt_rand(0,$imgWidth),
mt_rand(0,$imgHeight), 3, 3, $textColor);
}}
imagefill($im,0,0,$backgroundColor);
list($x, $y) = $this->ImageTTFCenter($im, $text, $font, $fontSize);
imagettftext($im, $fontSize, 0, $x, $y, $textColor, $font, $text);
imagejpeg($im,NULL,90);/* Showing image */
header('Content-Type: image/jpeg');/* defining the image type to be shown in browser widow */
imagedestroy($im);/* Destroying image instance */
if(isset($_SESSION)){
$_SESSION['captcha_code'] = $text;/* set random text in session for captcha validation*/
}
}
/*for random string*/
protected function random($characters=6,$letters = '23456789bcdfghjkmnpqrstvwxyz'){
$str='';
for ($i=0; $i<$characters; $i++) {
$str .= substr($letters, mt_rand(0, strlen($letters)-1), 1);
}
return $str;
}
/*function to convert hex value to rgb array*/
protected function hexToRGB($colour)
{
if ( $colour[0] == '#' ) {
$colour = substr( $colour, 1 );
}
if ( strlen( $colour ) == 6 ) {
list( $r, $g, $b ) = array( $colour[0] . $colour[1], $colour[2] . $colour[3], $colour[4] . $colour[5] );
} elseif ( strlen( $colour ) == 3 ) {
list( $r, $g, $b ) = array( $colour[0] . $colour[0], $colour[1] . $colour[1], $colour[2] . $colour[2] );
} else {
return false;
}
$r = hexdec( $r );
$g = hexdec( $g );
$b = hexdec( $b );
return array( 'r' => $r, 'g' => $g, 'b' => $b );
}
/*function to get center position on image*/
protected function ImageTTFCenter($image, $text, $font, $size, $angle = 8)
{
$xi = imagesx($image);
$yi = imagesy($image);
$box = imagettfbbox($size, $angle, $font, $text);
$xr = abs(max($box[2], $box[4]));
$yr = abs(max($box[5], $box[7]));
$x = intval(($xi - $xr) / 2);
$y = intval(($yi + $yr) / 2);
return array($x, $y);
}
}
PHP Captcha Download File
