Task Fusion Definition

After the segmentation task(s) are performed, there will likely be overlaps between the different Entity polygons that were detected. These overlaps arise from intentionally overlapped image regions, minor overlaps due to polygon post-processing, and overlaps due to the same Entity being detected by multiple tasks. There are three supported task fusion options:

• harmonize (recommended)

  The harmonize option attempts to find a compromise between the different overlapping geometries. If an overlap is greater than 50% of either Entity, the Entities are merged into a single output Entity. If the overlap is less than 50%, the overlapping region is subtracted from the larger Entity.

• union

  Regardless of the amount of overlap between Entities, any overlapping input Entities are fused into a single output Entity.

• larger

  Regardless of the amount of overlap between Entities, if two input Entities overlap, only keep the larger Entity.

Following these fusion operations, two additional checks will be applied.

• min_distance_between_entities

  When polygons are subtracted from one another (as they are in the harmonize operation), the space between the cells is zero. In order to provide some separation between cells, a minimum distance between these cell can be specified.

• min_final_area

  When polygons are subtracted from one another (as they are in the harmonize operation), the polygon with area removed may fall below the plausible size for a cell. The min_final_area defines this minimum size; smaller cells are removed from the output.

Usage:

"segmentation_task_fusion": {
    "entity_fusion_strategy": "harmonize",
    "fused_polygon_postprocessing_parameters": {
        "min_distance_between_entities": 1,
        "min_final_area": 500
    }
}