K. Pietraszkiewicz, MEAN-SQUARE OF THE WAVE-ABERRATION AS A COHERENT MEASURE OF THE IMAGEQUALITY, Journal of the Optical Society of America. A, Optics, image science,and vision., 11(3), 1994, pp. 1053-1055
A new measure of image quality and a new definition of the center of a
point spread are proposed. Determination of the value of this measure
is equivalent to simultaneous optimization of the reference sphere. T
his measure resolves itself into the mean square of the wave aberratio
n in the case of a small aberration.