Focus pre-processing chain for object detection in high resolution remote sensing images

This paper proposes simple focusing techniques to assist high resolution remote sensing imagery users in the task of object detection and recognition. Efficient algorithms in this field are very time consuming and thus hardly compatible with the size of remote sensing data from the market. Meanwhile, objects and areas of interest are usually sparsely spread over the scene. There might even be parts of the scene in which there are little or no chance to meet a given kind of object. We intend to show that with some very simple and fast rules, an astonishing amount of the image can be discarded with little or no important data loss. A priori and templates based techniques are described along with examples. The use of synoptic primal sketches to ease fast assessment of the images content is also developed.