Strain mapping from HRTEM images

Strain mapping is defined as a numerical image processing technique that measures the local shifts of image details around a crystal defect with respect to the ideal, defect-free, positions in the bulk. The most common algorithms for strain mapping are based on peak finding (real space) and geometric phase (Fourier space) methods. In this paper, we discuss both algorithms and propose an alternative algorithm (Peak Pairs) based on the detection of pairs of intensity maxima in the affine transformed space which exhibits good behavior at dislocations. Quantitative results are reported from experiments to determine local stresses in different types of quantum heterostructures.