1. A data correction apparatus which corrects data associated with an image of an object, comprising: an input unit configured to input vector data obtained by combining data to be corrected; a generation unit configured to execute dimension reduction processing by projecting the vector data onto a subspace to generate a dimensionally reduced projection vector, and dimension restoration processing by restoring a dimensionality of the dimensionally reduced projection vector to generate a plurality of dimensionally restored vector data for respective types of fluctuation of the object in the image; a determination unit configured to determine the fluctuation of the object; and an output unit configured to determine corrected data based on the plurality of dimensionally restored vector data and the fluctuation of the object determined by said determination unit, and to output the corrected data.