imagegd

(PHP 4 >= 4.0.7, PHP 5)

imagegd — Output GD image to browser or file

Описание

bool imagegd ( resource $image [, string $filename ] )

Outputs a GD image to the given filename .

Параметри

image: Ресурс на изображение, върнат от някоя от функциите за създаване на изображения като например imagecreatetruecolor().
filename: The path to save the file to. If not set or NULL, the raw image stream will be outputted directly.

Връщани стойности

Връща TRUE при успех или FALSE при неуспех.

Примери

Example #1 Outputting a GD image


<?php
// Create a blank image and add some text
$im = imagecreatetruecolor(120, 20);
$text_color = imagecolorallocate($im, 233, 14, 91);
imagestring($im, 1, 5, 5,  "A Simple Text String", $text_color);

// Output the image
imagegd($im);

// Free up memory
imagedestroy($im);
?>

Example #2 Saving a GD image


<?php
// Create a blank image and add some text
$im = imagecreatetruecolor(120, 20);
$text_color = imagecolorallocate($im, 233, 14, 91);
imagestring($im, 1, 5, 5,  "A Simple Text String", $text_color);

// Save the gd image
// The file format for GD images is .gd, see http://www.libgd.org/GdFileFormats
imagegd($im, 'simple.gd');

// Free up memory
imagedestroy($im);
?>

Бележки

Забележка: The GD format is commonly used to allow fast loading of parts of images. Note that the GD format is only usable in GD-compatible applications.

Вж. също

imagegd2() - Output GD2 image to browser or file

add a note User Contributed Notes imagegd

rohitkumar at cftechno dot com 29-Jun-2011 05:15


<?php



/*

* Captcha image for security 

*/



session_start();



class CaptchaSecurityImages {

 

   var $font = 'monofont.ttf';

 

   function generateCode($characters) {

      /* list all possible characters, similar looking characters and vowels have been removed */

      $possible = '23456789bcdfghjkmnpqrstvwxyz';

      $code = '';

      $i = 0;

      while ($i < $characters) { 

         $code .= substr($possible, mt_rand(0, strlen($possible)-1), 1);

         $i++;

      }

      return $code;

   }

 

   function CaptchaSecurityImages($width='120',$height='40',$characters='6') {

      $code = $this->generateCode($characters);

      /* font size will be 75% of the image height */

      $font_size = $height * 0.75;

      $image = imagecreate($width, $height) or die('Cannot initialize new GD image stream');

      /* set the colours */

      $background_color = imagecolorallocate($image, 255, 255, 255);

      $text_color = imagecolorallocate($image, 20, 40, 100);

      $noise_color = imagecolorallocate($image, 100, 120, 180);

      /* generate random dots in background */

      for( $i=0; $i<($width*$height)/3; $i++ ) {

         imagefilledellipse($image, mt_rand(0,$width), mt_rand(0,$height), 1, 1, $noise_color);

      }

      /* generate random lines in background */

      for( $i=0; $i<($width*$height)/150; $i++ ) {

         imageline($image, mt_rand(0,$width), mt_rand(0,$height), mt_rand(0,$width), mt_rand(0,$height), $noise_color);

      }

      /* create textbox and add text */

      $textbox = imagettfbbox($font_size, 0, $this->font, $code) or die('Error in imagettfbbox function');

      $x = ($width - $textbox[4])/2;

      $y = ($height - $textbox[5])/2;

      imagettftext($image, $font_size, 0, $x, $y, $text_color, $this->font , $code) or die('Error in imagettftext function');

      /* output captcha image to browser */

      header('Content-Type: image/jpeg');

      imagejpeg($image);

      imagedestroy($image);

      $_SESSION['security_code'] = $code;

   }

 

}

 

$width = isset($_GET['width']) && $_GET['width'] < 600 ? $_GET['width'] : '120';

$height = isset($_GET['height']) && $_GET['height'] < 200 ? $_GET['height'] : '40';

$characters = isset($_GET['characters']) && $_GET['characters'] > 2 ? $_GET['characters'] : '6';

 

$captcha = new CaptchaSecurityImages($width,$height,$characters);

 

?>

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