An algorithm for approximation of the laser sheet of a line in images obtained by means of a array photodetector is considered. A description of a mathematical model of an image of a laser sheet is presented. The influence of the dimensions of the Gaussian beam, angle of inclination, and dimensions of a treated fragment on the standard deviation and bias of the estimators in the determination of the parameters of the line is investigated by means of simulation modeling. Recommendations for image processing are given.