College of Marine Science and Technology, China University of Geosciences, Wuhan 430074, China.
Key Laboratory of Geological Survey and Evaluation of Ministry of Education, China University of Geosciences, Wuhan 430074, China.
Sensors (Basel). 2020 Dec 8;20(24):7032. doi: 10.3390/s20247032.
Low inter-class variance and complex spatial details exist in ground objects of the coastal zone, which leads to a challenging task for coastal land cover classification (CLCC) from high-resolution remote sensing images. Recently, fully convolutional neural networks have been widely used in CLCC. However, the inherent structure of the convolutional operator limits the receptive field, resulting in capturing the local context. Additionally, complex decoders bring additional information redundancy and computational burden. Therefore, this paper proposes a novel attention-driven context encoding network to solve these problems. Among them, lightweight global feature attention modules are employed to aggregate multi-scale spatial details in the decoding stage. Meanwhile, position and channel attention modules with long-range dependencies are embedded to enhance feature representations of specific categories by capturing the multi-dimensional global context. Additionally, multiple objective functions are introduced to supervise and optimize feature information at specific scales. We apply the proposed method in CLCC tasks of two study areas and compare it with other state-of-the-art approaches. Experimental results indicate that the proposed method achieves the optimal performances in encoding long-range context and recognizing spatial details and obtains the optimum representations in evaluation indexes.
沿海地区地物的类内方差小且空间细节复杂,这给高分遥感影像的海岸带土地覆盖分类(CLCC)任务带来了挑战。最近,全卷积神经网络在 CLCC 中得到了广泛应用。然而,卷积算子的固有结构限制了感受野,导致无法捕获局部上下文。此外,复杂的解码器带来了额外的信息冗余和计算负担。因此,本文提出了一种新的注意力驱动的上下文编码网络来解决这些问题。其中,轻量级全局特征注意力模块用于在解码阶段聚合多尺度空间细节。同时,嵌入具有长距离依赖关系的位置和通道注意力模块,通过捕获多维全局上下文,增强特定类别的特征表示。此外,引入多个目标函数来监督和优化特定尺度的特征信息。我们将所提出的方法应用于两个研究区域的 CLCC 任务,并与其他最先进的方法进行了比较。实验结果表明,所提出的方法在编码长距离上下文和识别空间细节方面表现最优,并在评价指标中获得了最优的表示。