Conversion from 8-bit PNG depth labels to metric depth

    def convert_depth_labels_in_meters(self,png_label):
        
        #Interpolation obtained via calibration on a test scenario
        metric_depth = -4.586e-09 * (png_label ** 4) + 3.382e-06 * (png_label ** 3) - 0.000105 * (
                png_label ** 2) + 0.04239 * png_label + 0.04072
       	

        return metric_depth