Viewing distance measurement using a single camera

In order to determine the viewing distance with low complexity and high transportability, a measurement method using a single camera is proposed in this paper. After the image of the face of the viewer is taken by a single camera, it is input to the preprocessing component and the resolution of the image is transformed into a given resolution for fitting function. The pixel distance between binocular pupils in the image is determined in the image processing component. Then, the viewing distance is calculated by applying the data of the binocular pupil pixel distance into the fitting function. Experimental results show that the relative error between the detected viewing distance and the actual viewing distance of the proposed method can be controlled within ± 1.2% and the standard deviation can be controlled below 2.1631 cm within 120cm distance. And the proposed method has also stability and universal implantable capability.