Modelling of error due to background lighting in measurements obtained from range camera

Range cameras are able to measure the distance between the sensor and the surface of objects for each image pixel, in a just single instant, producing an image of distance. It also measure the intensity and amplitude for each pixel, in order to produce images of intensity and amplitude, respectively. Like any measure, those obtained by the distance of cameras have errors, and one of the factors that produces errors in the measurements is the external lighting at the environment. In this study it was analyzed the influence of the external lighting on the calculated values ​​of distance, amplitude and intensity. In a dark room it was made up some experiments, where it was obtained images of distance images, intensity and amplitude of a white wall, where various lighting levels generated by two lamps whose beams converged on the center of the wall. Some conclusions are: the external illumination increased distance values; the ratio of the distance error and the amplitude variation is directly proportional and linear; and the relationship between the distance error and the variation of intensity it was also linear for values ​​lower intensities than 26600, at 21 MHz of modulation frequency. It was achieved linear correlation above 0.9. The image of intensity is more sensitive to the effect of external lighting than the amplitude image

Key-words:
Background illumination; Range camera; Errors