Bilinear interpolation and various bi-cubic interpolations are frequently adopted in image resizing. However the bi-quadratic function is rarely considered due to its phase distortion problem. In this paper

we propose an image resizing method via bi-quadratic B-spline interpolation

where 4×4 pixels are sampled symmetrically in the local image.\r\nand resamping the image with the function

Thus the phase distortion problem can be avoided. The proposed algorithm is a local algorithm and can be easily extended.According to our experiment results

the proposed bi-quadratic B-spline interpolation algorithm has better image peak signal-to-noise ratio (PSNR) and MISSIM than bi-linear interpolation

bi-cubic convolution

Catmull-Rom cubic interpolation

or the Dodgson interpolation algorithm.The results are comparable to the bi-cubic B-spline interpolation algorithm

though the visual effects are not as good as that

but still better than the Dodgson algorithm. The computing time is reduced by nearly one-third compared to the bi-cubic B-spline interpolation algorithm.Since the algorithm has not carried on the special handling to the image edge features

so the method does not suit the rich details texture images

which we will focus on in the future days.