A method and an apparatus for generating images are provided. The method includes generating a first sinogram for a state of an object from among states of the object based on a motion of the object, and a second sinogram for the states, based on data obtained from the object, and determining a region of interest (ROI) of the object based on the first sinogram. The method further includes extracting, from the second sinogram, third sinograms corresponding to the ROI, and estimating motion information of the ROI based on the third sinograms. The method further includes correcting the data based on the motion information.