Advantages of Feature Extraction
• Analysis of multiple data sources
• Reproducible results and repeatability
• Versatility and adaptability
• Analysis of data pixel by pixel, point by point
• Analysis of objects measures such as shape, size, texture, shadow, context, association etc.
• Scientific measure of accuracy
• Reduce labor cost and time
Object Based Image Analysis (OBIA)
• Segmentation: The process of grouping together pixels based on certain criteria.
• These objects are then classified based on
– Radiometry/reflectance
– Geometry/shape
– Neighborhood/context
– Topology/network structure
Image Segmentation
• The problem: The explicit determination of the amount and distribution of the desired ground phenomena.
– Edge detection
– Region growing
• Automated Feature Extraction– Extract– Fuse and Extract– Extract, Fuse and Extract– Classification
• GIS/Carto– Editing
• Achieve cartographic standards• Achieve accuracy standards
– Data simplification– Data validation
• QA/QC– Accuracy check– Quality check– Reporting
Feature Extraction Process
Impervious Surface Mapping• Incorporate historical data• Parcel mapping• Road centerlines• Land-cover• Impervious surface• Zoning maps
Road CenterlinesParcel Mapping
Why?
• Reproducible
• Reduce field work
• Reduces manual edits
• Simplifies the comparison process
• Leverages existing data!
Questions / Comments
Kent L ParkGeospatial Project Manager
317.281.2092