红外弱小目标的检测是红外搜索跟踪系统(IRST)中的一项关键技术,常用的目标检测算法存在受海杂波严重、虚警率较高等问题,分析了海天背景下红外图像的背景、小目标的特征,提出了一种海杂波背景下的红外小目标检测算法。首先统计图像的行均值和梯度,用最小二乘法拟合出海天线,然后利用形态学算子抑制图像背景,并采用自适应阈值将图像二值化,最后分析图像的梯度特征,抑制海杂波和云层的干扰。实验结果表明,该方法能精确地提取海天线,稳定地提取海天背景下的弱小目标,虚警率低于5%,目标检测概率超过97%。

Infrared dim targets detection is a key part of the infrared searching and tracking (IRST) system. Commonly used algorithm is sensitive to sea clutter and the false alarm ratio is high. An algorithm of dim target detection under complicated background of sea and sky is proposed based on the background and target feature analysis. Firstly, the mean and gradient of every line was added up and the sea-sky-line was fit out using least square. Then, the mathematical morphology operators was used to suppress the image background and image was segmented by adaptive threshold. Finally, the sea clutter and edge of the clouds were suppressed based on the image feature analysis. The experiment results prove that the method can locate the sea-sky-line precisely and detect dim targets steadily. The false alarm rate is less than 5% and the detection probability is more than 97%.