An image registration device includes: an image acquisition unit that acquires a plurality of images； a divided region setting unit that sets divided regions by dividing each registration processing target of the plurality of images； a pixel value conversion method determination unit that determines, for each set of divided regions set at the same position of the respective registration processing targets, a pixel value conversion method for each divided region based on a pixel value of each divided region of the set； a pixel value conversion unit that performs pixel value conversion within each divided region of the set of divided regions using the determined pixel value conversion method for each divided region； and a registration processing unit that performs registration processing on the plurality of images subjected to pixel value conversion.
