1. An method for active induction thermography, comprising: using a camera to acquire a plurality of images of an object to be inspected at each of a plurality of acquisition directions, for each of the plurality of acquisition directions: deriving a complex-value Fourier-transformed image from the plurality of images acquired at that acquisition direction; determining an average phase value from the Fourier-transformed image; and deriving a phase-corrected Fourier-transformed image from the average phase value and the Fourier-transformed image, wherein the phase-corrected Fourier-transformed images for the plurality of acquisition directions have an essentially equal average phase value with respect to each other, and deriving a combined Fourier-transformed image from the phase-corrected Fourier-transformed images for the plurality of acquisition directions.