function create($width, $height = null, $color = null) {
        $height = $height ? : $width;
        $this->width = $width;
        $this->height = $height;
        $this->image = imagecreatetruecolor($width, $height);
        $this->original_info = array(
            'width' => $width,
            'height' => $height,
            'orientation' => $this->get_orientation(),
            'exif' => null,
            'format' => 'png',
            'mime' => 'image/png'
        );
        if ($color) {
            $this->fill($color);
        }
        return $this;
    }