Georaster Processing
DroneDB provides tools for processing and analyzing georeferenced rasters -- orthophotos, DEMs, multispectral imagery, and thermal data.
Border Masking
Remove black or white border pixels from an orthophoto by making them transparent. This is useful for orthomosaics that have empty areas around the survey footprint.
CLI
ddb mask orthophoto.tif
# outputs orthophoto_masked.tif
| Option | Description |
|---|---|
-o, --output | Output path (default: <input>_masked.tif) |
-n, --near | Tolerance in grey levels (default: 15) |
-w, --white | Treat white as the border color instead of black |
-c, --color | Custom border color as r,g,b |
Examples
# Remove black borders (default)
ddb mask orthophoto.tif
# Custom tolerance and output path
ddb mask orthophoto.tif -o output.tif -n 20
# Search for white borders
ddb mask orthophoto.tif -w
# Custom border color (dark blue)
ddb mask orthophoto.tif -c 0,0,128
In Hub
Use the Mask Borders toolbar button on a GeoRaster entry. The masked result is added to the dataset as a new COG.
Raster Export
Export a raster as a GeoTIFF with custom visualization parameters (band selection, formula, colormap, rescale). Useful for generating false-color composites or vegetation index maps.
In Hub
Open a multispectral or thermal raster, adjust the visualization settings (preset, bands, formula, colormap), and click Export to download the result as a GeoTIFF.
Parameters
| Parameter | Description |
|---|---|
| Preset | Visualization preset (true color, false color, NDVI, etc.) |
| Bands | Custom band mapping (R, G, B channel assignment) |
| Formula | Vegetation index formula (NDVI, NDRE, etc.) |
| Colormap | Color map for single-band output (viridis, RdYlGn, iron, etc.) |
| Rescale | Min/max value range for stretching |
Raster Profile
Sample a single-band raster along a line to produce an elevation or value chart.
CLI
The raster profile functionality is available through the Hub interface and the API.
In Hub
- Open a DEM, DSM, DTM, or thermal GeoTIFF
- Click the Raster Profile toolbar button
- Draw a line across the raster
- An equispaced chart of value vs. distance (in meters) appears
The profile samples up to 4096 points along the line, clamped between 2 and 4096 based on the line length.
Nodata Handling
DroneDB automatically detects and handles nodata values in rasters:
- Alpha band: Pixels with alpha = 0 are treated as nodata
- Per-band nodata: The
NODATAvalue stored in the GeoTIFF metadata is respected - Pre-masking: Nodata pixels are set to a sentinel value before processing (tiling, statistics, etc.)
This ensures that transparent borders, masked areas, and invalid pixels do not affect statistics, thumbnails, or tile generation.
Raster Area Statistics
Compute statistics over a rectangular region of a raster:
| Statistic | Description |
|---|---|
| Min | Minimum value in the region |
| Max | Maximum value in the region |
| Mean | Average value |
| StdDev | Standard deviation |
| Median | Median value |
Available for any single-band raster (DEMs, thermal, multispectral bands). In Hub, draw a rectangle on the map to see the statistics panel.
Raster Profile, Area Statistics, and Border Masking work on any GeoRaster -- orthophotos, DEMs, multispectral imagery, and thermal data.