1. A method for reducing noise in a tomographic image, comprising: acquiring phase information of a noise component signal, the signal being provided as a signal corresponding to a noise component of the tomographic image and included in a spectrum interference signal output from a detector of a swept source optical coherence tomography device; acquiring a tomographic image in response to a spectrum interference signal with a corrected phase deviation based on the acquired phase information; and reducing the noise component of this tomographic image.