Enhanced Crack Segmentation Using Meta’s Segment Anything Model with Low-Cost Ground Truths and Multimodal Prompts

Crack detection and rehabilitation are critical components of a pavement’s life cycle. Various detection methods have been developed, among which classification, object detection, and segmentation deep-learning approaches have been revolutionary. Segmentation models enable the pixel-wise delineation of crack networks, which are used in quantifying severity, defect type, and condition index of distress. However, supervised segmentation algorithms require a substantial amount of pixel-accurate ground truth labels, which are challenging to obtain. Additionally, current models exhibit limited generalizability to unseen data, with state-of-the-art models performing inadequately in detecting low-severity cracks. This article therefore presents a novel crack segmentation approach leveraging Meta’s Segment Anything Model (SAM) and low-cost ground truths. We fine-tune the SAM model using box, points, and text prompts, enhancing the model’s generalizability and improving crack fidelity. The model achieves a 94% F1 score on the authors’ dataset and 91% and 77% F1 scores on the Fully Convolutional Network (FCN) dataset and Crack Forest Dataset (CFD), respectively. Our approach outperforms the U-Net, DeepLabV3+, and TransUNet models on the FCN dataset and achieves comparable performance on the CFD dataset. Exploring different loss combinations during training reveals that a dice and binary cross-entropy loss combination does not significantly outperform a dice and focal loss combination. The use of text prompts in querying the images is also examined. Although initial results look promising, their segmentation and classification accuracies are relatively lower.