2-D signal interpolation using subsequence FFT

An efficient 2-D interpolation algorithm is presented which is a 2-D extension of the subsequence approach for 1-D interpolation introduced by K. Prasad and P. Satyanarayana (1986), which avoids the redundant operations in the inverse transform. An improved intermediate sequence is introduced to preserve the Hermitian symmetry when interpolating a real-valued signal. The resulting algorithm is significantly more efficient than the 2-D FFT method of J.W. Adams (1987). It is also more convenient, since it permits the use of the IFFT with a size that is the same as that of the original FFT