Imaging device analysis methods, imaging device analysis systems, and articles of manufacture are described. According to one embodiment, an imaging device analysis method includes providing a plurality of first responsivity values corresponding to a first responsivity function of an imaging device, first determining that error associated with the first responsivity values is unacceptable, providing a plurality of second responsivity values corresponding to a second responsivity function of the imaging device responsive to the first determining, wherein the providing the second responsivity values comprises constraining the second responsivity values to comprise values of the same sign, second determining error associated with the second responsivity values, and selecting the second responsivity values responsive to the second determining yielding acceptable error.