1. An optical image measurement device comprising: an imaging forming part configured to form tomographic images G( 1 )-G(m) at a plurality of cross sections of a measurement object, an image processor configured to execute an arithmetic operation based on a tomographic image at one cross section of the plurality of cross sections and another tomographic image at each of one or more cross sections other than the one cross section, thereby forming a new tomographic image at the one cross section, wherein the image processor is configured to, for a cross section corresponding to each scanning line Ri (1<i<m), execute an arithmetic operation based on a tomographic image Gi at the cross section, a tomographic image G(i+1) at a cross section corresponding to a scanning line R(i+1), and a tomographic image G(i−1) at a cross section corresponding to a scanning line R(i−1), so as to form a new tomographic image G(i) at the cross section corresponding to the scanning line Ri to recreate new tomographic images G( 2 )-G(m−1).