**Appendix B**

To verify that our method is also suitable for correction of side-scan sonar images in other batches, we used our algorithm (bilateral filtering) to enhance them. Because we lacked other batches of side-scan sonar images, we were only able to obtain images by clipping them from previous studies [7–9] and the quality of the side-scan sonar images was poor. However, the effects of the enhanced images verified the adaptivity of our algorithm.

**Figure A1.** Side-scan sonar image enhancement from Zhao, J et al. [9]: (**a**) original image with changes in sediments and (**b**) enhanced image (bilateral filtering, *A* = 140, *a* = 17).

**Figure A2.** Side-scan sonar image enhancement from previous studies [7,8]: (**a**) original and (**b**) enhanced image from Capus, C et al. [7]; (**c**) original image and (**d**) enhanced image from Capus, C et al. [8] (bilateral filtering, *A* = 140, *a* = 15).

#### **References**


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