Large Image Support¶
DIVE supports large image datasets (GeoTIFF/TIFF) through tiled pyramid access on Web (Girder large_image) and Desktop (local GeoTIFF tile server).
Dynamic range in the viewer¶
For Web tiled TIFF datasets (large-image type), use the
Image Adjustments panel to apply percentile stretch while
annotating. DIVE passes stretch parameters to Girder tile requests so 16-bit (and other
high bit-depth) data can be viewed interactively without baking a fixed min/max into the
file first.
Pre-scaling to 8-bit COG (below) is still useful when you want a fixed display range at import time or when preparing files for tools that do not support dynamic tile styling.
On Web, an upload batch that contains only .tif / .tiff files is classified as a
large-image dataset (not an image sequence). JPEG or PNG uploads remain image sequences.
Requirement: Internal Overviews¶
Large images must include internal overview levels (reduced-resolution pyramid levels) for tile rendering. Files without internal overviews can fail to load in the large-image viewer.
If a file is missing overviews, convert it before import.
Check a File¶
Run:
gdalinfo --stats "input-file.tif"
Confirm that the output includes overview entries and record the min/max stats for each band. You will use those values for scaling during conversion.
Convert to a Pyramidal COG¶
Use gdal_translate with COG output, internal overviews, and explicit scaling:
gdal_translate "input-file.tif" "input-file_cog_scaled.tif" \
-of COG \
-ot Byte \
-scale <min> <max> 0 255 \
-co BLOCKSIZE=256 \
-co COMPRESS=DEFLATE \
-co PREDICTOR=2 \
-co BIGTIFF=IF_SAFER \
-co NUM_THREADS=ALL_CPUS \
-co OVERVIEWS=IGNORE_EXISTING \
-co RESAMPLING=LANCZOS \
-co OVERVIEW_RESAMPLING=AVERAGE
Replace <min> and <max> with the values from gdalinfo --stats (per band as needed).
Notes¶
- If your data is RGB, use per-band scaling options (
-scale_1,-scale_2,-scale_3) when channels need different ranges. - Re-import the converted
*_cog_scaled.tiffile into DIVE.