Accuracy test procedure for image evaluation techniques.

A procedure has been developed to determine the accuracy of image evaluation techniques. In the procedure, a target having orthogonal test arrays is photographed with a high quality optical system. During the exposure, the target is subjected to horizontal linear image motion. The modulation transfer functions of the images in the horizontal and vertical directions are obtained using the evaluation technique. Since all other degradations are symmetrical, the quotient of the two modulation transfer functions represents the modulation transfer function of the experimentally induced linear image motion. In an accurate experiment, any discrepancy between the experimental determination and the true value is due to inaccuracy in the image evaluation technique. The procedure was used to test the Perkin-Elmer automated edge gradient analysis technique over the spatial frequency range of 0-200 c/m. This experiment demonstrated that the edge gradient technique is accurate over this region and that the testing procedure can be controlled with the desired accuracy. Similarly, the test procedure can be used to determine the accuracy of other image evaluation techniques.