Multi-rank Method: Achieving Projection Transformation with Adjustable Accuracy and Speed

In the field of GIS, it is frequently required to carry out projection transformation of massive raster maps or remote sensing images. In this paper, a method named multi-rank method is presented. It is able to achieve projection transformation with adjustable accuracy and speed. All the points in a map or image are divided into four ranks. Rank-4 points, which scatter in the map, are transformed by analytical solution. Rank-3 points are transformed by third-order polynomials, which employ rank-4 points as control points. Rank-2 points are transformed by second-order polynomials, which employ rank-3 points as control points. Rank-1 points are transformed by first-order polynomials, which employ rank-2 points as control points. Accuracy and speed of transformation can be adjusted flexibly by choosing parameters of ranking. Experimental results show that the proposed method is able to get high accuracy with high speed. * Corresponding author. Tel: 86-731-4576434. E-mail: [email protected]