4-Neighbor Connectivity
Cells are connected only through shared edges.
Best used when: diagonal contact should remain separate.
Raster to Polygon
Convert connected raster cells with the same value/class into vector polygon features.
Shared Raster ToolsEnd-User DocumentationTheory + Formula + Parameters1. What This Feature Does
Convert connected raster cells with the same value/class into vector polygon features.
Cloud workflow: choose data → configure the scientific method → run → review the resulting layer/report. No programming is required.
2. Recommended Workflow
Choose the source band.
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Optionally select which values are included.
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Choose 4- or 8-neighbor connectivity.
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Polygonize the raster regions.
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Review small/sliver polygons and simplify if appropriate.
3. Theory, Methods & Equations
8-Neighbor Connectivity
Cells connected by edges or corners are considered neighbors.
Best used when: diagonally touching regions should be treated as one connected region.
4. Input Data
| Input | Type | Requirement | Description |
|---|---|---|---|
| Input Raster | raster | Required | Raster layer to polygonize. One raster band is converted to vector polygon regions. |
5. Parameters Available in the Application
| Parameter | Default | Choices / Range | How to Use It |
|---|---|---|---|
| Raster Band | — | — | Select one band from the selected raster. Available bands are loaded from the Raster Info application; arbitrary band numbers are not accepted by the user interface. |
| Pixel Connectivity | 4 | 4-neighbour, 8-neighbour | 4-neighbour joins pixels through shared edges. 8-neighbour also joins diagonally touching pixels. |
| Exclude Nodata | On | — | Do not create polygons for the raster nodata/masked region. |
| Exclude Zero | Off | — | Ignore pixels with value 0. Useful for classification rasters where zero represents background. |
| Maximum Polygon Features | 250000 | 1 to 1000000 | Safety limit. Polygonization stops with an error if the output would exceed this number of polygon features. |
6. Output & Interpretation
The result should be interpreted according to the selected method and the physical meaning of the input data. Preserve source units, coordinate reference information, NoData meaning, acquisition date, and preprocessing level when comparing results.
Scientific interpretation: an algorithm can produce a numerically valid result even when the input data are unsuitable. Always check masks, units, sensor characteristics, spatial resolution and reference data.
Important: Raster-to-vector conversion follows pixel boundaries. Very fine rasters can produce complex polygons with many vertices.
7. Best Practices
- Use analysis-ready inputs and remove invalid/cloud/noise artifacts that are not part of the target phenomenon.
- Choose parameters from the physical scale of the data, not only from visual appearance.
- Keep categorical and continuous rasters conceptually separate when selecting interpolation/resampling methods.
- Compare the result with the source image and independent reference information.
- Document the settings used when results will be compared across dates, sensors or study areas.