红外点目标检测中的能量累积

Energy accumulation in infrared point target detection

针对在红外图像目标检测中利用传统动态规划进行能量累积存在较大的能量扩散效应,且检测速度慢、检测概率低等问题提出了一种基于动态规划的红外点目标检测能量累积方法。该方法在传统的动态规划递推式中引入了加权信息熵衰减因子和方向性信息权值。加权信息熵可以反映目标的运动信息,当某搜索区域存在目标运动时,能量累积衰减率小;当目标不存在时,能量累积衰减率大,从而保证了目标轨迹区域能量的大幅累积。方向性信息能够反映目标的运动轨迹方向,能使能量以大概率沿着目标运动方向有效累积。用本文方法和传统的DPA能量累积方法对平均信噪比为2.1725的12帧序列图像进行实验和比较,结果显示,传统DPA能量累积要到第9帧才能到达检测阈值,检测概率为0.956,并且会产生虚假轨迹;而本文方法到第5帧就已经到达检测阈值,检测概率为0.915。结果表明,该方法缩小了能量扩散效应区域,提高了点目标的检测概率和检测速度。

To overcome the shortcomes of large energy distraction, slow detection speed and low detection probability in target detection using the technique of energy accumulation based on traditional Dynamic Programming Algorithm （DPA）, an energy accumulation method of IR point target detection based on DPA is proposed. The Weighted Information Entropy （WIE） attenuation factor and directional weights are imported into the DPA recursive formula. Research results indicate that the WIE can reflect the targets＇ moving information. When a target exists in the searching window, accumulated energy shows a little attenution, which guarantees the larger energy accumulation and less energy distraction in the area of target track. Moreover, directional weights can reflect the moving direction of a target and make the energy accumulation toward the moving direction with a large probability. An experiment is carried out for 12 frames of image sequences with the average SNR of 2. 172 5. Results show that the accumulated energy reaches the detecting threshold in the 5th frame with the detection probability of 0. 915 by using the proposed method, while the energy reaches thethreshold in the 9th frame with the detection probability of 0. 956 by using the traditional method. It is coneluded that the method is able to reduce the area of energy distraction tremendously and can increase the detecting probability and speed obviously.