Multi-Deformation Aware Attention Learning for Concrete Structural Defect Classification

In this work, we propose a deep multi-deformation aware attention learning (MDAL) architecture comprising of multi-scale committee of attention (MSCA) and fine-grained feature induced attention (FGIA) modules to classify multi-target multi-class defects in concrete structures found in civil infrastructures. The MDAL network is composed of interleaved MSCA and FGIA modules to encode crucial fine-grained deformation-aware information from concrete images. The novel attention mechanism is able to localize specific defect regions within an image and extracts crucial discriminative information in multi-scale fashion ranging from coarser to finer features without using any preprocessing step, such as region-of-interest selection or denoising. Our proposed attention mechanism enables the MDAL architecture to automatically classify multiple overlapping defect classes present in the concrete images and leads to an end-to-end trainable deep network. Experimental results on three large concrete defect datasets and ablation studies show that our MDAL network outperforms the current state-of-the-art methodologies significantly.