pendalf89\filemanager\models\Mediafile::createDefaultThumb PHP Method

    public function createDefaultThumb(array $routes)
    {
        $originalFile = pathinfo($this->url);
        $dirname = $originalFile['dirname'];
        $filename = $originalFile['filename'];
        $extension = $originalFile['extension'];
        Image::$driver = [Image::DRIVER_GD2, Image::DRIVER_GMAGICK, Image::DRIVER_IMAGICK];
        $size = Module::getDefaultThumbSize();
        $width = $size[0];
        $height = $size[1];
        $thumbUrl = "{$dirname}/" . $this->getThumbFilename($filename, $extension, Module::DEFAULT_THUMB_ALIAS, $width, $height);
        $basePath = Yii::getAlias($routes['basePath']);
        Image::thumbnail("{$basePath}/{$this->url}", $width, $height)->save("{$basePath}/{$thumbUrl}");
    }