NAME

KEYWORDS

SYNOPSIS

DESCRIPTION

i.hyper.export exports a hyperspectral 3D raster map (raster_3d) from GRASS to an external file. By default, the module writes a native .ihyper gzip archive. It also supports export to compressed multi-band GeoTIFF, HDF5, or Zarr.

The export process converts the 3D raster map into 2D raster slices using r3.to.rast, creates a temporary imagery group, and writes all bands into a single multi-band GeoTIFF file with r.out.gdal. All temporary rasters and groups are automatically removed after export.

i.hyper.export can also write a native .ihyper gzip archive for exact transfer of a hyperspectral raster_3d (inspired by r.pack). This stores the full map in native GRASS form together with hyper.json; related composites can be included optionally, but are not exported by default. HDF5 and Zarr exports write the cube in (band,row,col) order, where the first axis is the spectral axis.

FUNCTIONALITY

• Exports the complete hyperspectral 3D raster map as a single multi-band GeoTIFF, HDF5 cube, Zarr cube, or native .ihyper archive.
• Preserves the spectral band order and spatial alignment of the input map.
• Uses DEFLATE compression with PREDICTOR=3 for efficient floating-point storage.
• Handles null values as -9999.
• Automatically sets the computational region to match the input 3D raster map.

NOTES

• Native .ihyper export stores the complete grid3 map directory together with hyper.json.
• All intermediate rasters and imagery groups are temporary and removed automatically after export.
• The exported GeoTIFF keeps spatial georeferencing and embeds hyperspectral dataset metadata together with per-band wavelength, FWHM, and validity metadata from hyper.json.
• HDF5 and Zarr exports store the full hyperspectral cube in (band,row,col) order and include both the full hyper.json metadata payload and spatial metadata needed to interpret the cube.
• The output file can be opened in software such as QGIS, ENVI, or Python libraries (rasterio, gdal, h5py, zarr).
• Existing related composites can be included in .ihyper export optionally with the -c flag.

OPTIONS

• input – Input 3D raster map (required).
• output – Output file name (required). Example: output=prisma_3d.ihyper.
• format – Export format: ihyper (default), gtiff, h5, or zarr.
• chunks – Chunk sizes in band,row,col order. The first value is the spectral axis. This option is shown for all formats but used only for h5 and zarr. Use 0,0,0 for automatic chunk sizes.

EXAMPLES

# Example 1: Export PRISMA 3D raster map to native .ihyper archive (default)
i.hyper.export input=prisma@PERMANENT \
               output=/data/prisma_3d.ihyper

# Export native hyperspectral archive
i.hyper.export input=p2ld \
               output=/data/hyperspectral_data.ihyper \
               format=ihyper

# Export native hyperspectral archive and include existing composites
i.hyper.export input=p2ld \
               output=/data/hyperspectral_data.ihyper \
               format=ihyper -c

# Export as HDF5 cube with explicit chunk sizes in band,row,col order
i.hyper.export input=p2ld \
               output=/data/hyperspectral_data.h5 \
               format=h5 \
               chunks=8,256,256

# Export as Zarr cube with automatic chunk sizes
i.hyper.export input=p2ld \
               output=/data/hyperspectral_data.zarr \
               format=zarr \
               chunks=0,0,0

OUTPUT

The output is a native .ihyper archive by default, or a multi-band GeoTIFF, HDF5, or Zarr dataset when format= is set explicitly. GeoTIFF uses compression (DEFLATE + PREDICTOR=3) and stores per-band hyperspectral metadata. HDF5 and Zarr store the full cube in (band,row,col) order together with embedded metadata.

SEE ALSO

AUTHORS

SOURCE CODE

Available at: i.hyper.export source code (history)

Latest change: Wednesday Jun 17 14:05:16 2026 in commit: 2b69c1e5403d2a3377c287af027fcbad020a088c

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