Simple captcha php script not displaying text on image

Question

I was hoping to get in touch with someone on a situation that I cannot find the solution to anywhere.

I am trying to create a captcha on my website using php and although I was able to create an image and create the random captcha text.

I am unable to over lay the two. Here is my code:

<?PHP

session_start();


function generateRandomString($length = 10) {
    $letters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
    $len = strlen($letters);
    $letter = $letters[rand(0, $len - 1)];
    $text_color = imagecolorallocate($image, 0, 0, 0);
    $word = "";
    for ($i = 0; $i < 6; $i++) {
        $letter = $letters[rand(0, $len - 1)];
        imagestring($image, 7, 5 + ($i * 30), 20, $letter, $text_color);
        $word .= $letter;
    }
    $_SESSION['captcha_string'] = $word;

}


function security_image(){

   // $code = isset($_SESSION['captcha']) ? $_SESSION['captcha'] : generate_code();
    //$font = 'content/fonts/comic.ttf';

    $width = '110';
    $height = '20';
    $font_size = $height * 0.75;
   // $image = @imagecreate($width, $height) or die('GD not installed');
               global $image;
    $image = imagecreatetruecolor($width, $height) or die("Cannot Initialize new GD image stream");

               $background_color = imagecolorallocate($image, 255, 255, 255);  
               imagefilledrectangle($image,0,0,200,50,$background_color);


               $line_color = imagecolorallocate($image, 64,64,64); 
               for($i=0;$i<10;$i++) {
    imageline($image,0,rand()%50,200,rand()%50,$line_color);
               }

               $pixel_color = imagecolorallocate($image, 0,0,255);
               for($i=0;$i<1000;$i++) {
                              imagesetpixel($image,rand()%200,rand()%50,$pixel_color);
               }

               //$textbox = imagettfbbox($font_size, 0, $font, $code);
               //$textbox = imagettfbbox($font_size, 0, $randomString);

    $x = ($width - $textbox[4]) / 2;
    $y = ($height - $textbox[5]) / 2;
   // imagettftext($image, $font_size, 0, $x, $y, $text_color, $font , $code);
   imagettftext($image, $font_size, 0, $x, $y, $text_color , $word);


    $images = glob("*.png");
    foreach ($images as $image_to_delete) {
        @unlink($image_to_delete);
    }
    imagepng($image, "image" . $_SESSION['count'] . ".png");

    header('Content-Type: image/png');
    imagepng($image);
    imagedestroy($image);

}

security_image();




?>

I have no idea what I’m doing wrong. I’ve spent over 10 hours on this “display text” issue. I don’t understand and I am desperate for help. I even downloaded working captcha version from other resources that break once I upload it to my server. I have no idea whats going on. At first I thought there was something wrong with my server but the fact that I can even create the pixels, lines image means that it is at least working.

Please help!!!! 

UPDATE--------------------------------------------- Thank you for your suggestions. Here is the edited code. I'm still getting the same issue.

<?PHP

session_start();


function security_image(){
    global $image;

   // $code = isset($_SESSION['captcha']) ? $_SESSION['captcha'] : generate_code();

    $font = 'content/fonts/comic.ttf';

    $width = '110';
    $height = '20';
    $font_size = $height * 0.75;

    $image = imagecreatetruecolor($width, $height) or die("Cannot Initialize new GD image stream");

    $background_color = imagecolorallocate($image, 255, 255, 255);  
    imagefilledrectangle($image,0,0,200,50,$background_color);


    $line_color = imagecolorallocate($image, 64,64,64); 
    for($i=0;$i<10;$i++) {
    imageline($image,0,rand()%50,200,rand()%50,$line_color);
    }

    $pixel_color = imagecolorallocate($image, 0,0,255);
    for($i=0;$i<1000;$i++) {
        imagesetpixel($image,rand()%200,rand()%50,$pixel_color);
    }

    $letters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
    $len = strlen($letters);
    $letter = $letters[rand(0, $len - 1)];
    $text_color = imagecolorallocate($image, 0, 0, 0);
    $word = "";
    for ($i = 0; $i < 6; $i++) {
        $letter = $letters[rand(0, $len - 1)];
        imagestring($image, 7, 5 + ($i * 30), 20, $letter, $text_color);
        $word .= $letter;
    }
    $_SESSION['captcha_string'] = $word;

    /*texbox unitinitialized (removed for the sake of just showing the word size doesnt matter)
        $x = ($width - $textbox[4]) / 2;
        $y = ($height - $textbox[5]) / 2;
    */

    $x = ($width) / 2;
    $y = ($height) / 2;
    imagettftext($image,$font, 4, $x, $y, $word);



    header('Content-Type: image/png');
    imagepng($image);
    imagedestroy($image);

}
security_image();?>

i made some suggested changes but the code seems to still do the same thing. Just display the lines and pixels as expected but the text still is missing... ?

please excuse the commented code. those were my other attempts that failed but i kept it in there to show what i have tried already. — NeoSketo
– NeoSketo, Commented Nov 20, 2014 at 14:32
Your imagestring should be in your security_image function. This is the function that will add the text into your image :-). Do something like : ImageString($image, 4, $x, $y, $_SESSION['word']); — DarkBee
– DarkBee, Commented Nov 20, 2014 at 14:44
thanks i added that and its still giving me the same error. for some reason the text just doesnt want to show...? :I — NeoSketo
– NeoSketo, Commented Nov 20, 2014 at 21:43

vaso123 · Accepted Answer · 2014-11-20 15:40:45Z

1

There are some several "errors" in your functions, let's fix them:

In generateRandomString()

generateRandomString($length = 10)

$lenght is not used its scope.

$text_color = imagecolorallocate($image, 0, 0, 0);

$image is uninitialized

In security_image() function:

$textbox is uninitialized
$text_color and $word is uninitialized.
And Wrong parameter count for imagettftext() You add 7 parameters, and forget the font file parameter.

answered Nov 20, 2014 at 15:40

vaso123

12.4k4 gold badges38 silver badges68 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

NeoSketo Over a year ago

thanks a bunch. ok i reorganized the code to i got rid of $length, since i wasnt using it. i moved $text_color below where $image is initialized. Actually i moved the whole text generation function in one function. I removed $textbox because i wasnt using it. And i added the $font parameter in imagettftext, i didnt initialize any font file paramiter? am i supposed to? i uncommented my $font parameter. I'm still getting the same result as before. i can see lines and pixels but no text... im wondering if the text is actually there, and its behind the image...

NeoSketo · Accepted Answer · 2014-11-21 19:14:09Z

0

found the problem. using this: http://php.net/manual/en/function.imagettftext.php

i was able to see that the font location was incorrect. using the example on that page and editing it to my needs worked.

answered Nov 21, 2014 at 19:14

NeoSketo

5251 gold badge10 silver badges28 bronze badges

Collectives™ on Stack Overflow

Simple captcha php script not displaying text on image

2 Answers 2

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related