Captcha using Phalcon GD

Hello everyone. I found best captcha extension from zf2. But it works not fast. I guess if I use Phalcon GD library - it will be faster. I need this code to rewrite using Phalcon GD.

protected function generateImage($id, $word)
    {
        $font = $this->getFont();

        if (empty($font)) {
            throw new Exception\NoFontProvidedException('Image CAPTCHA requires font');
        }

        $w     = $this->getWidth();
        $h     = $this->getHeight();
        $fsize = $this->getFontSize();

        $imgFile   = $this->getImgDir() . $id . $this->getSuffix();

        if (empty($this->startImage)) {
            $img = imagecreatetruecolor($w, $h);
        } else {
            // Potential error is change to exception
            ErrorHandler::start();
            $img   = imagecreatefrompng($this->startImage);
            $error = ErrorHandler::stop();
            if (!$img || $error) {
                throw new Exception\ImageNotLoadableException(
                    "Can not load start image '{$this->startImage}'",
                    0,
                    $error
                );
            }
            $w = imagesx($img);
            $h = imagesy($img);
        }

        $textColor = imagecolorallocate($img, 0, 0, 0);
        $bgColor   = imagecolorallocate($img, 255, 255, 255);
        imagefilledrectangle($img, 0, 0, $w-1, $h-1, $bgColor);
        $textbox = imageftbbox($fsize, 0, $font, $word);
        $x = ($w - ($textbox[2] - $textbox[0])) / 2;
        $y = ($h - ($textbox[7] - $textbox[1])) / 2;
        imagefttext($img, $fsize, 0, $x, $y, $textColor, $font, $word);

        // generate noise
        for ($i=0; $i < $this->dotNoiseLevel; $i++) {
            imagefilledellipse($img, mt_rand(0, $w), mt_rand(0, $h), 2, 2, $textColor);
        }
        for ($i=0; $i < $this->lineNoiseLevel; $i++) {
            imageline($img, mt_rand(0, $w), mt_rand(0, $h), mt_rand(0, $w), mt_rand(0, $h), $textColor);
        }

        // transformed image
        $img2     = imagecreatetruecolor($w, $h);
        $bgColor = imagecolorallocate($img2, 255, 255, 255);
        imagefilledrectangle($img2, 0, 0, $w-1, $h-1, $bgColor);

        // apply wave transforms
        $freq1 = $this->randomFreq();
        $freq2 = $this->randomFreq();
        $freq3 = $this->randomFreq();
        $freq4 = $this->randomFreq();

        $ph1 = $this->randomPhase();
        $ph2 = $this->randomPhase();
        $ph3 = $this->randomPhase();
        $ph4 = $this->randomPhase();

        $szx = $this->randomSize();
        $szy = $this->randomSize();

        for ($x = 0; $x < $w; $x++) {
            for ($y = 0; $y < $h; $y++) {
                $sx = $x + (sin($x*$freq1 + $ph1) + sin($y*$freq3 + $ph3)) * $szx;
                $sy = $y + (sin($x*$freq2 + $ph2) + sin($y*$freq4 + $ph4)) * $szy;

                if ($sx < 0 || $sy < 0 || $sx >= $w - 1 || $sy >= $h - 1) {
                    continue;
                } else {
                    $color   = (imagecolorat($img, $sx, $sy) >> 16)         & 0xFF;
                    $colorX  = (imagecolorat($img, $sx + 1, $sy) >> 16)     & 0xFF;
                    $colorY  = (imagecolorat($img, $sx, $sy + 1) >> 16)     & 0xFF;
                    $colorXY = (imagecolorat($img, $sx + 1, $sy + 1) >> 16) & 0xFF;
                }

                if ($color == 255 && $colorX == 255 && $colorY == 255 && $colorXY == 255) {
                    // ignore background
                    continue;
                } elseif ($color == 0 && $colorX == 0 && $colorY == 0 && $colorXY == 0) {
                    // transfer inside of the image as-is
                    $newcolor = 0;
                } else {
                    // do antialiasing for border items
                    $fracX  = $sx - floor($sx);
                    $fracY  = $sy - floor($sy);
                    $fracX1 = 1 - $fracX;
                    $fracY1 = 1 - $fracY;

                    $newcolor = $color   * $fracX1 * $fracY1
                              + $colorX  * $fracX  * $fracY1
                              + $colorY  * $fracX1 * $fracY
                              + $colorXY * $fracX  * $fracY;
                }

                imagesetpixel($img2, $x, $y, imagecolorallocate($img2, $newcolor, $newcolor, $newcolor));
            }
        }

        // generate noise
        for ($i=0; $i<$this->dotNoiseLevel; $i++) {
            imagefilledellipse($img2, mt_rand(0, $w), mt_rand(0, $h), 2, 2, $textColor);
        }

        for ($i=0; $i<$this->lineNoiseLevel; $i++) {
            imageline($img2, mt_rand(0, $w), mt_rand(0, $h), mt_rand(0, $w), mt_rand(0, $h), $textColor);
        }

        imagepng($img2, $imgFile);
        imagedestroy($img);
        imagedestroy($img2);
    }

Who can help to rewrite captcha code using Phalcon GD? I will be very grateful

edited Mar '16

Man, you can for sure use this code, it will not be much slower than code written in PHP using Phalcon. Dont care about that 1-2 ms slowness and take the profit of finished code which is maintained by the community.



6.8k

Why do you think that Phalcon GD will have almost equal speed as PHP? Phalcon GD invokes C methods directly, if I'm not mistaken

And how many images do you want to generate per page? Hundreds or thousands? Probably not and thats it, for one captcha image per page the speed benefit will be almost non existent and its much better to use good maintained and tested code than make your own.