Video Distance Measurement Technique Using Least Squares Based Sharpness Cost Function

Abstract

A wide range of precision applications requires video measuring systems that achieve a large number of successive measurements and deliver fast results. Their efficiency is essentially given by the technical performances of the used equipment and by the measurement technique on which they operate. In order to enhance the reliability of such a system, the paper presents a new method of measuring the distance with a single video camera intended to assess the distance at which the object of interest to the camera is located. The technique makes use of a least squares-based sharpness cost function and determines the distance between the camera and the object of interest by minimizing the least squares deviation of the current sharpness values from the sharpness values obtained by calibration. It involves the current sharpness calculation phase, the normalization phase, the phase of calculating the deviations of the current sharpness from the dependencies obtained by calibration and the phase of determining the minimum deviation index.