Low-Cost Reflectance-Based Method for the Radiometric Calibration of Kinect 2

Gaming sensors have been established as low-cost sensors for the geometric reconstruction of objects. However, their radiometric capabilities remain unnoticed. Exploiting these radiometric features, several studies based on the assessment of material properties and pathological analysis could be performed using this low-cost sensor. In this paper, a reflectance-based radiometric method for the second generation of gaming sensors, Kinect 2, is presented and discussed. In particular, a repeatable methodology generalizable to different gaming sensors by means of a calibrated reference panel with Lambertian behavior is developed. The relationship between the received power and the final digital level is obtained by means of a combination of linear sensor relationship and signal attenuation, into a least squares adjustment with an outlier detector. The results confirm that the quality of the method (standard deviation better than 2% in laboratory conditions and discrepancies lower than 7% under real conditions) is valid for exploiting the radiometric possibilities of this low-cost sensor, which ranges from the pathological analysis (moisture and crusts), to agricultural and forest resource evaluation.