code: public function computeResize()
  	{
  		$resizeCoordinates = System::getContainer()
  			->get('contao.image.resize_calculator')
  			->calculate(
  				$this->prepareResizeConfig(),
  				new ImageDimensions(
  					new Box($this->fileObj->viewWidth, $this->fileObj->viewHeight),
  					$this->fileObj->viewWidth !== $this->fileObj->width
  				),
  				$this->prepareImportantPart()
  			)
  		;
  
  		return array
  		(
  			'width' => $resizeCoordinates->getCropSize()->getWidth(),
  			'height' => $resizeCoordinates->getCropSize()->getHeight(),
  			'target_x' => -$resizeCoordinates->getCropStart()->getX(),
  			'target_y' => -$resizeCoordinates->getCropStart()->getY(),
  			'target_width' => $resizeCoordinates->getSize()->getWidth(),
  			'target_height' => $resizeCoordinates->getSize()->getHeight(),
  		);
  	}
docs: Calculate the resize coordinates
  
  @return array The resize coordinates (width, height, target_x, target_y, target_width, target_height)