<title>Subpixel edge location shift</title>

Abstract

Subpixel accuracy gauging with solid state cameras has been of great interest in past years. Efforts to reduce errors in subpixel edge locations were directed at the subpixel interpolation technique or in the physical structure of the sensor itself. In this paper we present data which supports the opinion that the major error is caused by the sampling technique. We examine the nonlinearity of the subpixel edge location when moving the edge in equidistant steps in horizontal and vertical directions according to the solid state sensor. The relation between the virtual and physical pixels and the influence of the edge shift on the camera calibration and robot guidance are briefly discussed in this paper as well.