Pimcore\Image\Adapter\Imagick::setBackgroundImage PHP Method

    public function setBackgroundImage($image, $mode = null)
    {
        $this->preModify();
        $image = ltrim($image, "/");
        $image = PIMCORE_DOCUMENT_ROOT . "/" . $image;
        if (is_file($image)) {
            $newImage = new \Imagick();
            $newImage->readimage($image);
            if ($mode == "cropTopLeft") {
                $newImage->cropImage($this->getWidth(), $this->getHeight(), 0, 0);
            } else {
                // default behavior (fit)
                $newImage->resizeimage($this->getWidth(), $this->getHeight(), \Imagick::FILTER_UNDEFINED, 1, false);
            }
            $newImage->compositeImage($this->resource, \Imagick::COMPOSITE_DEFAULT, 0, 0);
            $this->resource = $newImage;
        }
        $this->postModify();
        return $this;
    }