Object-Based Image Analysis (OBIA)
Overview
Object-Based Image Analysis (OBIA) is a method of analyzing remote sensing imagery that segments images into meaningful objects or regions based on spectral, spatial, and contextual information, often used for land cover classification and change detection in GIS.
Key Concepts
Segmentation groups pixels into homogeneous regions (objects). Classification assigns classes to objects based on attributes. Scale parameter controls the size of segmented objects. Shape vs. color balances spectral and geometric criteria in segmentation. Contextual features include relationships between neighboring objects. Hierarchy allows multi-scale analysis with parent-child object relationships.
OBIA vs. Pixel-Based
| Aspect | OBIA | Pixel-Based |
|---|---|---|
| Unit | Objects/segments | Individual pixels |
| Features | Shape, texture, context | Spectral values only |
| Noise | Reduced (smoothed) | Salt-and-pepper |
| Edges | Better preserved | Jagged |
| Processing | More complex | Simpler |
Appendix
Created: 2025-12-13 | Modified: 2025-12-13