A method for detecting a position of a sheet of light is described. A second derivative filter is applied to an intensity profile of a line of pixels. An ingress pixel position associated with an ingress zero-crossing second derivative value is determined. The ingress pixel position is between a first pixel position with a first minimum intensity value of the intensity profile and a second pixel position with a first maximum intensity value of the intensity profile. An egress pixel position associated with an egress zero-crossing second derivative value is determined. The egress pixel position is between a third pixel position with a second maximum intensity value of the intensity profile and a fourth pixel position with a second minimum intensity value of the intensity profile. A midpoint pixel position between the ingress pixel position and the egress pixel position is output as the position of the sheet of light.