Apparatus is provided for: storing at least one three-dimensional matrix C[M][N][K] of calibration data; performing singular value decomposition of each at least one three-dimensional matrix C[M][N][K] of calibration data to produce at least one first unitary rotation matrix U, at least one diagonal scaling matrix S and at least one second unitary rotation matrix V; and resizing each of the at least one first unitary rotation matrix U, the at least one diagonal scaling matrix S and the at least one second unitary rotation matrix V by removing dimensions therefrom, thereby producing resized matrices U, S and V.Corresponding decompression is also provided.