In communications using air-ground data link

the data that comes from various kinds of airborne image sensors is becoming huger and huger

but the bandwidth of the data link is relatively small.In order to improve image transmission efficiency in battle field condition

there is a requirement for CCD aerial camera using central projection acquired images to be transmitted with high fidelity and speed over long distance.This paper proposed an airborne automatic data reduction scheme to solve the aforementioned problem.The key of this scheme is automatic image matching and clipping.The algorithm utilizes the strong logic relativity between adjacent aero-photograph and it is based on the model of 2-D affine transform.Under the conditions of detecting no highlight moving target

the algorithm performs automatic clipping on overlapping part of two adjacent images by the use of Fourier-Mellin transform.The experimental results of automatic clipping and mosaic show that the proposed algorithm is computationally efficient and very easy to realize.It is a robust algorithm and can effectively reduce data quantity of the downside data link.All these prove that the proposed algorithm has great potential of being applied to practical use.