Infrared small target super-resolution (SR) aims to recover reliable and detailed high-resolution image with high-contrast targets from its low-resolution counterparts. Since the infrared small target lacks color and fine structure information, it is significant to exploit the supplementary information among sequence images to enhance the target. In this paper, we propose the first infrared small target SR method named local motion and contrast prior driven deep network (MoCoPnet) to integrate the domain knowledge of infrared small target into deep network, which can mitigate the intrinsic feature scarcity of infrared small targets. Specifically, motivated by the local motion prior in the spatio-temporal dimension, we propose a local spatio-temporal attention module to perform implicit frame alignment and incorporate the local spatio-temporal information to enhance the local features (especially for small targets). Motivated by the local contrast prior in the spatial dimension, we propose a central difference residual group to incorporate the central difference convolution into the feature extraction backbone, which can achieve center-oriented gradient-aware feature extraction to further improve the target contrast. Extensive experiments have demonstrated that our method can recover accurate spatial dependency and improve the target contrast. Comparative results show that MoCoPnet can outperform the state-of-the-art video SR and single image SR methods in terms of both SR performance and target enhancement. Based on the SR results, we further investigate the influence of SR on infrared small target detection and the experimental results demonstrate that MoCoPnet promotes the detection performance. The code is available at https://github.com/XinyiYing/MoCoPnet.
翻译:红外小目标超分辨率(SR)旨在从低分辨率图像中恢复可靠且详细的高分辨率图像,其中高对比度的目标是其中的重要部分。由于红外小目标缺乏颜色和细节结构信息,因此利用序列图像之间的补充信息来增强目标非常重要。本文提出了一种全新的红外小目标SR方法MoCoPnet(局部运动和对比度先验驱动深度网络),将红外小目标的领域知识融入深度网络中,从而可以缓解红外小目标天生的特征稀缺问题。
具体而言,受局部运动先验的启发,本文提出了一种局部时空注意力模块,以执行隐式帧对齐并将局部时空信息纳入以增强局部特征(尤其是小目标)。受局部对比度先验的启发,我们提出了一个中央差分残差组,将中央差分卷积纳入特征提取主干中,可以实现以中心为导向的梯度感知特征提取,进一步提高目标对比度。广泛的实验表明,我们的方法可以恢复准确的空间依赖关系并提高目标对比度。比较结果表明,MoCoPnet可以在SR性能和目标增强方面优于现有的视频SR和单图像SR方法。基于SR结果,我们进一步研究了SR对红外小目标检测的影响,实验结果表明MoCoPnet可以提高检测性能。代码可在https://github.com/XinyiYing/MoCoPnet找到。