Inverse-gradient adaptive interpolation algorithm

In view of the inherent shortcomings of edge-directed interpolation algorithm and locally- adaptive zooming algorithm, a new algorithm is proposed. The characteristic of the digital image is that the gray value in edge area is sharp, and the gray value in the non-edge area is smooth. In accordance with this characteristic, the linear interpolation was used along the edge orientation, and inverse gradient interpolation was used in the non-edge area. Experimental results demonstrate that this algorithm not only decreases the computational complexity, but also obtains the clear edge image and substantially improves the visual quality of the interpolated images over conventional linear interpolation.