Abstract: When using polynomial interpolation methods to zoom image,the quality of zooming image requires to be further improved,because the polynomial functions can only reflect the gradual change of data without the mutability of data.An image zooming method is presented using rational Coons interpolation patch with shape parameters.The method can reflect the gradual change and the mutability of data.The digital image is expressed to interpolation surfaces by using piecewise bicubic rational Coons interpolation patches.Then,the zooming image can be obtained by resampling the interpolation surfaces according to zoom demand.The satisfactory zooming image can be achieved through adjusting the shape parameters.Experimental results demonstrate that the proposed method is capable of maintaining clear borders of source images and efficient in computation for image zooming.