ManaPHP\Image\Adapter\Gd::crop PHP Method

    public function crop($width, $height, $offsetX = 0, $offsetY = 0)
    {
        if (version_compare(PHP_VERSION, '5.5.0') < 0) {
            $image = imagecreatetruecolor($width, $height);
            imagealphablending($image, false);
            imagesavealpha($image, true);
            imagecopy($image, $this->_image, 0, 0, $offsetX, $offsetY, $width, $height);
        } else {
            $rect = ['x' => $offsetX, 'y' => $offsetY, 'width' => $width, 'height' => $height];
            $image = imagecrop($this->_image, $rect);
        }
        imagedestroy($this->_image);
        $this->_image = $image;
        $this->_width = imagesx($image);
        $this->_height = imagesy($image);
        return $this;
    }