Fine-Tuned SAM Adaptation with Multi-scale Guidance for Automated Detection Toward Image-Based Core Length and RQD Measurement
摘要
Rock core logging is critical for evaluating rock mass quality, yet traditional manual measurement of rock quality designation (RQD) indicator from boreholes remains highly labor-intensive. To address the limitations of insufficient detection accuracy and generalizability in mainstream deep learning methods, we propose MG-FSAM4Seg, a vision foundation model adapted for rock core instance segmentation, combined with a fine-grained RQD analytics method. MG-FSAM4Seg adopts an enhanced multi-scale feature learning design that seamlessly integrates the Segment Anything Model (SAM) encoder with additional decoders, where the encoder is further fine-tuned via low-rank adaptation. We evaluate our model on two core imagery datasets, including the self-constructed Core1000 and the independent cross-project Core-G47, which exhibit considerable lithological and resolution differences, benchmarked against 15 advanced segmentation methods. On the Core1000 test set, MG-FSAM4Seg achieves competitive performance in both qualitative and quantitative evaluations, reaching an average precision of 88.07%. In a zero-shot transfer evaluation on Core-G47, the model maintains strong generalization, achieving an average precision of 86.46%. Moreover, RQD values estimated from MG-FSAM4Seg segmentation results, combined with our proposed core length calculation approach, show high agreement with manual measurements, yielding an R2 of over 0.95. These results confirm that MG-FSAM4Seg provides an effective solution for vision-based RQD analytics, demonstrating its potential to advance automated geological logging.