A fast vehicle detection method by UAV using region feature gradient

In order to detect ground vehicles from UAV in real time, a fast detection method using region feature gradient (RFG) was proposed. The RFG, which included the gradient mean amplitude and main directions, was used to find the potential position of target and its rotations rapidly. The gradient mean amplitude was first used to find the potential position of target, and the gradient integral image would make this process be computed very quickly. And the main directions of the target and potential position, which was computed by gradient histogram, were compared to find the rotation of the target. Finally, traditional recognition method (such as HOG) was adopted to accurately detect the target. Experimental results obtained against the VIVID database demonstrate that the proposed method is ten times faster than the improved method of HOG, and maintains a high recognition rate at the same time.