Feature Description
Extract all lines, also known as extract all isolines, generates qualified contour lines from surface models by specified parameters.
- The source dataset for isoline extraction must be DEM or Grid data.
Example
Open the "Terrain" datasource in the "ExerciseData/RasterAnalysis" folder containing 5-meter resolution DEM data. This example uses this dataset.
Feature Entry
- Spatial Analysis Tab -> Raster Analysis -> Surface Analysis -> Extract All Lines；
- Toolbox -> Raster Analysis Tools -> Surface Analysis -> Extract Isolines/Areas -> Extract All Lines.
Parameter Description
Base Value: The initial calculation value for generating isolines. The system calculates forward/backward at interval steps, thus not necessarily being the minimum isoline value. Accepts any numerical input. Default: 0. Example: For DEM data with elevation range 220-1550, setting base value=500 and interval=50 will generate isolines ranging from 250 to 1550.
Interval: The value difference between adjacent isolines, working with base value to determine isoline extraction range.
The system automatically calculates and displays result info after parameter configuration:
Maximum Raster Value: Highest value in source dataset (system-calculated, read-only).
Minimum Raster Value: Lowest value in source dataset (system-calculated, read-only).
Maximum Isoline: Highest isoline value in target dataset.
Minimum Isoline: Lowest isoline value in target dataset.
Isoline Count: Total number of isolines in target dataset.
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| Figure: Extract All Isolines |
- Configure common parameters including source data, target dataset, resampling coefficient in parameter settings, smoothing method, and smoothness. For common parameter configurations, see: Common Parameter Description.
- Set base value and interval in parameters.
- Click "OK" to complete extraction.