Feature Description
Calculates the geometry information of each zone in the raster data, including area, perimeter, centroid, or thickness, and outputs the result as a statistical raster. The extent and XY resolution of the output raster are consistent with the source raster.
The detailed description of geometric statistics types is as follows:
Area: In the input raster data, cells with the same raster value form a zone. The zone area is calculated as the product of the number of cells in the zone and the individual pixel size. In the output raster data, all cells in each zone are assigned the same area value, i.e., the area of that zone.
As shown in the figure below, zonal statistics are performed on raster data with a pixel size of 1, with the geometric statistics type selected as "Area". The raster values in the output result reflect the area values of each zone.
Perimeter: The perimeter of each zone is calculated by summing the lengths of cells that constitute the zone boundary. In the output raster data, all cells in each zone are assigned the same perimeter value.
Centroid: By calculating the eigenvalues and eigenvectors of each zone's shape, an ellipse is created to approximate the zone's geometry, and the center of the ellipse is computed as the zone's centroid. The raster value at the centroid is the source raster value of the zone it belongs to, while cells at other locations have no data.
Thickness: Calculates the distance from the outermost cell to the deepest or thickest point within each zone.
The explanation of raster value units is as follows:
When the statistics type is centroid, the raster value at the centroid is the source raster value of the zone it belongs to, with no unit concept.
For other statistics types, the raster value units are consistent with the units of the source raster data.
Parameter Description
| Parameter Name | Parameter Interpretation | Parameter Type |
|---|---|---|
| Grid Area Dataset | Only supports raster datasets with integer pixel format. Cells with the same raster value form a zone. Each zone does not need to be a continuous region; it can consist of multiple scattered areas. No-data areas are treated as blank regions and do not participate in the calculation. | Dataset |
| Geometric Statistics Type | Select the geometry type to be calculated, including area, perimeter, centroid, and thickness. | GeometricStatisticsMode |
| Target Datasource | The specified datasource used to store the result data. | Datasource |
| The Name Of The Resulting Dataset | The specified name for the resulting dataset. | String |
Output Result
| Parameter Name | Parameter Interpretation | Parameter Type |
|---|---|---|
| Raster Dataset | The statistical result raster dataset, with its extent and XY resolution identical to the source raster data. | DatasetGrid |
Application Example
After completing land use data classification, the classification results may have issues such as small patches or irregular boundaries, requiring further processing. The specific processing steps are as follows:
1. Prepare land use classification data.
2. Use the [Zonal Geometric Statistics] tool to calculate the area of each zone.
3. Based on the actual area distribution of land use types and analysis requirements, use [Algebraic Operation] to filter out areas with an area less than 100 square meters.
4. Finally, use the [Shrink] and [Expand] tools in [Raster Integration] to clean up the identified small areas.
Notes
- The centroid result may not be within the source raster region, and its pixel format is the same as the input raster. For other statistics types, the result grid pixel format is double.
Related Topics
Zonal Geometric Statistics to Attribute Table