. A typical target recognition system usually involves three stages: image enhancement, image segmentation, and object identification. We propose an efficient image segmentation approach to segment man-made targets from unmanned aerial vehicle (UAV) imagery using curvature information derived from image histogram smoothed by Bezier splines. The experimental results show that by enhancing the histogram instead of the original image, similar segmentation results can be obtained in a more efficient way. Algorithm complexity is analyzed. Segmentation results from images enhanced by variants of diffusion methods are also presented for comparison. Real-time automatic target recognition (aTr) is the main objective of the proposed approach.