An Improved Approach to the Cubic-Spline Interpolation

Cubic-spline interpolation (CSI) scheme is known to resample the discrete image data based on the least-square method with the cubic convolution interpolation (CCI) function. It is superior in performance to other interpolation functions for digital image processing. In this paper, an improved approach to the CSI scheme is proposed for the decimation and interpolation of image data. The proposed CSI scheme combines the least-square method with six-point CCI function to improve performance. Moreover, a novel low-complexity implementation algorithm is proposed to simplify the decimation and achieve improvement of the computational efficiency. Computer simulations indicate that the proposed CSI scheme can achieve better performance without increasing the computational complexity compared with the four-point CSI scheme.