The method proposed by BESSETTES and DESACHY [V. Bessettes, 1997] [V. Bessettes, 1996] works on multispectral SPOT-XS and P+XS images, in the aim of classifying urban zones according to their density.

• General Principle
• Definitions of the Built Up Areas and the Urban Density
• Application
• Extraction of the Urban Areas
• Angles of Gradient Vectors
• Median Filter
• Segmentation into Regions
• Hysteresis Thresholding, Edge Closure and Aggregation
• Samples
• Split and Merge Algorithm
• Computation of the Urban Density
• Street Classification
• Partition of the Urban Area