Hi, I am trying to implement captcha for our website using php. For this, I am trying to generate random image on the fly. Can anyone please guide what could be the best way to create image on the fly in php with random text. Thanks in advance.
To create image on the fly for the purpose of captcha: you can first generate random number then store the random number in the session and then generate the image with random number. To generate image on the fly, you can use php image functions.
Sample code:
function CreateSecurityImage($sessionName) { //Generate random number $text = rand();
//Set random number in session SetSessionValue($sessionName, $text);
//Set the image width and height $width = 130; $height = 50;
//Create the image resource $image = ImageCreate($width, $height);
//We are making three colors, white, black and gray $white = ImageColorAllocate($image, 255, 255, 255); $black = ImageColorAllocate($image, 0, 0, 0); $grey = ImageColorAllocate($image, 204, 204, 204);
//Make the background black ImageFill($image, 0, 0, $grey);
//Add randomly generated string in white to the image ImageString($image, 5, 30, 3, $text, $black); //Plain image
//Tell the browser what kind of file is come in header("Content-Type: image/jpeg");
//Output the newly created image in jpeg format ImageJpeg($image);
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