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Vectorization

Converts raster data into vector data.


Introduction

For more information, please read the block description.

Block type: PROCESSING

This block converts raster data into vector data.

The input for this block should be a thematic raster with relatively few classes so that the output geometry is meaningful. Examples: outputs from the processing blocks K-Means Clustering, Land Cover or NDVI Threshold.

Supported parameters

  • n_sieve_pixels: Minimum number of pixels in each geometry patch. Default is 1.

Example parameters using the data block SPOT Display (Streaming) and the processing blocks K-Means Clustering and Vectorization.

{
  "oneatlas-spot-aoiclipped:1": {
    "bbox": null,
    "time": null,
    "limit": 3,
    "intersects": {
      "type": "Polygon",
      "coordinates": [
        [
          [
            18.42631,
            -33.912732
          ],
          [
            18.420799,
            -33.922741
          ],
          [
            18.44355,
            -33.924784
          ],
          [
            18.441069,
            -33.913781
          ],
          [
            18.42631,
            -33.912732
          ]
        ]
      ]
    },
    "zoom_level": 17
  },
  "k-means-clustering:1": {
    "n_clusters":8
  },
  "vectorising:1": {
    "n_sieve_pixels": 20
  }
}

Output format

Output format is a GeoJSON file.

Advanced

Additional parameters

You can additionally set these parameters:

  • dst_crs: Output coordinate reference system. Set with the EPSG code. Default is EPSG:4326 or WGS 84.

  • src_band: Band number to use for vectorisation. Default is 1 (first band).

  • n_connectivity_pixels: Number of connected pixels required to make a patch. Default is 4. Other possible values: 8 (includes diagonal connections).