基于相位谱的红外小目标搜索算法研究

针对红外小目标搜索阶段中图像背景稀疏的特点,提出了一种利用图像相位谱计算显著图和定位目标的新方法。与传统的利用海天线和海岸线对目标进行搜索的方法相比,本文算法的计算复杂度大大降低,并弥补了其受气温影响而不能准确定位海天线和海岸线的不足;与利用Itti模型的方法相比,该算法克服了其不能有效分离目标和背景的缺点。阐述了利用离散傅里叶变换(Discrete Fourier Transform,DFT)和离散余弦变换(Discrete Cosine Transform,DCT)计算相位谱的两种方法及它们之间的一致性。构建了利用图像相位谱计算显著图的数学模型,明确了模型参数选择的作用和意义。通过理论和实例证明了本文算法对于稀疏背景下小目标定位的可行性和高效性。

Search Algorithm for Small Infrared Targets Based on Phase Spectrum

According to the fact that the background of a small infrared target is sparse in the searching stage, a novel target locating method which uses a salient map based on the phase spectrum in an image is proposed. Compared with the traditional target search method based on sea-sky-line or coastline, this method has reduced its computational complexity greatly and overcome the shortage that the sea-sky-line or coastline can not be located accurately due to the unstable temperature. Compared with the method using an Itti model, the algorithm has overcome the weakness that the target can not be separated from the background. Two methods which use Discrete Fourier Transform (DFT) and Discrete Cosine Transform (DCT) to calculate the image phase spectrum are presented and their consistency is proved. A mathematic model which uses phase spectrum to calculate saliency map is established. Parameter selection of the model is explained. The theory and examples show that this algorithm is feasible and efficient.