PHP captcha::setForegroundText示例

        $b = hexdec($b);
        return array($r, $g, $b);
    }
    /**
     * Set image header
     *
     * @return void
     */
    public function create()
    {
        header("Content-type: image/png");
        $colorBg = $this->makeCanvasColor();
        $colorFont = $this->makeFontColor();
        $font = $this->getFont();
        imagefilledrectangle($this->image, 0, 0, 399, 99, $colorBg);
        imagettftext($this->image, $this->fontSize, 0, 2, 40, $colorFont, $font, $this->code);
        imagepng($this->image);
        ImageDestroy($this->image);
    }
}
session_start();
//$code = captcha::makeHash();
$code = captcha::setForegroundTextFromFile('words/en_US.txt', 7);
$_SESSION['captcha'] = $code;
$canvasColor = null;
if (!empty($_GET['canvasColor'])) {
    $canvasColor = $_GET['canvasColor'];
}
$image = new captcha();
$image->setForegroundText($code)->setCanvasColor($canvasColor)->create();