Practical edge-based modulation transfer function measurement.

The accuracy and precision of the modulation transfer function (MTF) of a sampled imaging system are affected by the shift-variant nature of subpixel binning of the pixel values in edge-based methods. This study demonstrates that a binning phase selected from a small number of binning phases can achieve a practical precision criterion for the MTF measurement. Furthermore, the new method proposed in this paper approximates the non-aliased, fundamental MTF without edge angle estimation and the following subpixel binning. The algorithm simply averages the aliased MTFs calculated from the row-by-row edge gradients in the region of a bitonal edge image and removes an assumed aliasing component. This method is also applicable to an oblique and non-straight edge.