When detecting objects over large areas, geosam uses tiled processing which can split objects that span tile boundaries into multiple polygons. This function merges polygons that are close together, healing those splits.
Arguments
- x
A geosam object or sf object with detection results.
- buffer
Distance in meters to buffer polygons before checking for overlap. Larger values merge polygons that are further apart. Default is 2.
- by_prompt
If TRUE and a
promptcolumn exists, only merge polygons with the same prompt value. Default is TRUE.
Value
An sf object with merged polygons. Scores are aggregated by taking the maximum score from merged polygons.
Details
This function is useful when you notice objects being split at regular intervals (tile boundaries). The default buffer of 2 meters catches most boundary splits without merging truly separate objects.
For aggressive merging of nearby objects (not just boundary splits), use a larger buffer value, but be aware this may merge objects that should remain separate.
Examples
if (FALSE) { # \dontrun{
# Detect buildings over a large area (uses tiling internally)
buildings <- sam_detect(
bbox = c(-118.5, 34.0, -118.4, 34.1),
text = "building",
zoom = 18
)
# Merge any buildings split at tile boundaries
merged <- sam_merge_edges(buildings)
# More aggressive merging (5m buffer)
merged <- sam_merge_edges(buildings, buffer = 5)
} # }