1. A method for correcting geometric distortion in a digitally captured image, comprising: (a) receiving an uncorrected digital image of a phantom having a plurality of fiduciary marks; (b) locating an uncorrected position for each of the fiduciary marks; (c) mapping the uncorrected position to a corrected position for each fiduciary mark by (i) designating a fiduciary mark near the center of the digital image as the central fiduciary mark; (ii) determining the correct distance between adjacent fiduciary marks (iii) creating a digital map of the corrected position of each fiduciary mark by locating the positions relative to the central fiduciary mark that are multiples of the correct distance; (iv) associating the uncorrected position of each fiduciary mark with the closest corrected position until one of the fiduciary marks is more than a selected distance from a corrected position, then predicting the correct position of next fiduciary mark and then associating the predicted correct position with the closest correct position; and (d) interpolating or extrapolating the fiduciary mark mapping over all pixels in the uncorrected digital image, thereby creating a correction map for uncorrected digital images.