3D Image Correction for Time of Flight (ToF) Cameras

The distance image from the ToF camera is affected by errors mainly due to multiple light reflections inside the camera body and by the indirect light illuminating the objects in the scene. These errors can't be avoided and in particular cases can be as great as 50%. The method presented corrects the measured distance errors to objects labeled with a known strong contrast tag. A proposed algorithm determines the integral perturbing light signal and by subtracting it from the measured one we compute the (actual) corrected 3D image. Because the perturbing signal has a slow variation along the image it is computed only in the region of the tag with known contrast but the correction is performed in a wider region. An extension of this method to the entire 3D image can be implemented using amplitude modulated structured light. The method can be useful to other distance measuring devices using the same (ToF) principle.