Detecting Cadastral Boundary from Satellite Images Using U-Net model
Neda Rahimpour Anaraki, Maryam Tahmasbi, Saeed Reza Kheradpisheh
TL;DR
This work tackles automated cadastral boundary detection from satellite and UAV imagery using a transfer-learned U-Net with a ResNet34 backbone for three-class semantic segmentation (boundary, field, background). It carefully curates a small, patch-based dataset and employs Laplacian pre-processing, a 2-pixel boundary buffer, and a Jaccard–Focal loss to train the model, achieving high precision (approximately 0.88), solid recall (0.75), and a strong F-score (0.81) on two test farmland images from Iran. The boundaries are converted to vector shapefiles via skeleton-based post-processing, enabling GIS-ready outputs, and the approach demonstrates improved boundary quality and rural/urban discrimination relative to a Mask R-CNN baseline. The study provides a practical, transfer-learning pipeline for cadastral mapping in contexts with limited labeled data, while acknowledging vectorization limitations and suggesting avenues for future enhancement.
Abstract
Finding the cadastral boundaries of farmlands is a crucial concern for land administration. Therefore, using deep learning methods to expedite and simplify the extraction of cadastral boundaries from satellite and unmanned aerial vehicle (UAV) images is critical. In this paper, we employ transfer learning to train a U-Net model with a ResNet34 backbone to detect cadastral boundaries through three-class semantic segmentation: "boundary", "field", and "background". We evaluate the performance on two satellite images from farmlands in Iran using "precision", "recall", and "F-score", achieving high values of 88%, 75%, and 81%, respectively, which indicate promising results.
