Image analyzer for material structure using Fourier transform and principal component analysis

An image analyzer, comprising:

• a transformer configured to perform a Fourier transform on each of a plurality of original images representing a structure of a material to acquire, for each of the plurality of original images, an amplitude spectrum and a phase spectrum, and to calculate a power spectrum on the basis of the acquired amplitude spectrum, thereby acquiring a plurality of power spectra;
• an analyzer configured to perform principal component analysis on the plurality of power spectra and acquire principal components and principal component scores;
• and
• a reconstructor configured to reconstruct an image based on the principal components and principal component scores and output a feature image representing features of an original image among the plurality of original images, the reconstructor being configured to:
• generate a reconstructed no-change image obtained without changing the principal component scores as a reference image,
• calculate a first rate indicating a rate of change of a reconstructed power spectrum obtained by changing one or more of the principal component scores with respect to the power spectrum of the original image,
• modulate the amplitude spectrum of the original image according to the calculated first rate,
• generate a changed image based on the amplitude spectrum modulated according to the first rate and on the phase spectrum,
• generate a difference image based on the changed image and the reference image, and
• output the generated difference image as the feature image.