.. _raster.isis3:

================================================================================
ISIS3 -- USGS Astrogeology ISIS Cube (Version 3)
================================================================================

.. shortname:: ISIS3

.. built_in_by_default::

ISIS3 is a format used by the USGS Planetary Cartography group to store
and distribute planetary imagery data. GDAL provides
read/creation/update access to ISIS3 formatted imagery data.

ISIS3 files often have the extension .cub, sometimes with an associated
.lbl (label) file. When a .lbl file exists it should be used as the
dataset name rather than the .cub file. Since GDAL 2.2, the driver also
supports imagery stored in a separate GeoTIFF file.

In addition to support for most ISIS3 imagery configurations, this
driver also reads georeferencing and coordinate system information as
well as selected other header metadata.

Starting with GDAL 2.2, a mask band is attached to each source band. The
value of this mask band is 0 when the pixel value is the NULL value or
one of the low/high on-intstrument/processed saturation value, or 255
when the pixel value is valid.

Implementation of this driver was supported by the United States
Geological Survey.

ISIS3 is part of a family of related formats including PDS and ISIS2.

Driver capabilities
-------------------

.. supports_createcopy::

.. supports_create::

.. supports_georeferencing::

.. supports_virtualio::

Metadata
--------

Starting with GDAL 2.2, the ISIS3 label can be retrieved as
JSon-serialized content in the json:ISIS3 metadata domain.

For example:

::

   $ python 3
   from osgeo import gdal
   ds = gdal.Open('../autotest/gdrivers/data/isis3_detached.lbl')
   print(ds.GetMetadata_List('json:ISIS3')[0])
   {
     "IsisCube":{
       "_type":"object",
       "Core":{
         "_type":"object",
         "StartByte":1,
         "^Core":"isis3_detached.cub",
         "Format":"BandSequential",
         "Dimensions":{
           "_type":"group",
           "Samples":317,
           "Lines":30,
           "Bands":1
         },
         "Pixels":{
           "_type":"group",
           "Type":"UnsignedByte",
           "ByteOrder":"Lsb",
           "Base":0.000000,
           "Multiplier":1.000000
         }
       },
       "Instrument":{
         "_type":"group",
         "TargetName":"Mars"
       },
       "BandBin":{
         "_type":"group",
         "Center":1.000000,
         "OriginalBand":1
       },
       "Mapping":{
         "_type":"group",
         "ProjectionName":"Equirectangular",
         "CenterLongitude":184.412994,
         "TargetName":"Mars",
         "EquatorialRadius":{
           "value":3396190.000000,
           "unit":"meters"
         },
         "PolarRadius":{
           "value":3376200.000000,
           "unit":"meters"
         },
         "LatitudeType":"Planetographic",
         "LongitudeDirection":"PositiveWest",
         "LongitudeDomain":360,
         "MinimumLatitude":-14.822815,
         "MaximumLatitude":-14.727503,
         "MinimumLongitude":184.441132,
         "MaximumLongitude":184.496521,
         "UpperLeftCornerX":-4766.964984,
         "UpperLeftCornerY":-872623.628822,
         "PixelResolution":{
           "value":10.102500,
           "unit":"meters\/pixel"
         },
         "Scale":{
           "value":5864.945312,
           "unit":"pixels\/degree"
         },
         "CenterLatitude":-15.147000,
         "CenterLatitudeRadius":3394813.857978
       }
     },
     "Label":{
       "_type":"object",
       "Bytes":65536,
     },
     "History":{
       "_type":"object",
       "Name":"IsisCube",
       "StartByte":1,
       "Bytes":957,
       "^History":"r0200357_10m_Jul20_o_i3_detatched.History.IsisCube"
     },
     "OriginalLabel":{
       "_type":"object",
       "Name":"IsisCube",
       "StartByte":1,
       "Bytes":2482,
       "^OriginalLabel":"r0200357_10m_Jul20_o_i3_detatched.OriginalLabel.IsisCube"
     }
   }

or

::

   $ gdalinfo -json ../autotest/gdrivers/data/isis3_detached.lbl -mdd all

On creation, a source template label can be passed to the SetMetadata()
interface in the "json:ISIS3" metadata domain.

Creation support
----------------

Starting with GDAL 2.2, the ISIS3 driver supports updating imagery of
existing datasets, creating new datasets through the CreateCopy() and
Create() interfaces.

When using CreateCopy(), gdal_translate or gdalwarp, an effort is made
to preserve as much as possible of the original label when doing ISIS3
to ISIS3 conversions. This can be disabled with the USE_SRC_LABEL=NO
creation option.

The available creation options are:

-  .. co:: DATA_LOCATION
      :choices: LABEL, EXTERNAL, GEOTIFF.
      :default: LABEL

      To specify the location
      of pixel data. The default value is LABEL, ie imagery immediately
      follows the label. If using EXTERNAL, the imagery is put in a raw
      file whose filename is the main filename with a .cub extension. If
      using GEOTIFF, the imagery is put in a separate GeoTIFF file, whose
      filename is the main filename with a .tif extension.

-  .. co:: GEOTIFF_AS_REGULAR_EXTERNAL
      :choices: YES, NO
      :default: YES

      Whether the GeoTIFF file,
      if uncompressed, should be registered as a regular raw file. Defaults
      to YES, so as to maximize the compatibility with earlier version of
      the ISIS3 driver.

-  .. co:: GEOTIFF_OPTIONS

      Comma separated list of KEY=VALUE
      tuples to forward to the GeoTIFF driver. e.g.
      ``GEOTIFF_OPTIONS=COMPRESS=LZW``.

-  .. co:: EXTERNAL_FILENAME
      :choices: <filena,e>

      Override default external filename.
      Only for DATA_LOCATION=EXTERNAL or GEOTIFF.

-  .. co:: TILED
      :choices: YES, NO
      :default: NO

      Whether the pixel data should be tiled. Default
      is NO (ie band sequential organization).

-  .. co:: BLOCKXSIZE
      :default: 256

      Tile width in pixels. Only used if :co:`TILED=YES`.

-  .. co:: BLOCKYSIZE
      :default: 256

      Tile height in pixels. Only used if :co:`TILED=YES`.

-  .. co:: COMMENT

      Comment to add into the label.

-  .. co:: LATITUDE_TYPE
      :choices: Planetocentric, Planetographic
      :default: Planetocentric

      Value of Mapping.LatitudeType. If specified, and
      :co:`USE_SRC_MAPPING` is in effect, this will be taken into account to
      override the source LatitudeType.

-  .. co:: LONGITUDE_DIRECTION
      :choices: PositiveEast, PositiveWest
      :default: PositiveEast

      Value of Mapping.LongitudeDirection. If specified,
      and :co:`USE_SRC_MAPPING` is in effect, this will be taken into account to
      override the source LongitudeDirection.

-  .. co:: TARGET_NAME

      Value of Mapping.TargetName. This is
      normally deduced from the SRS datum name. If specified, and
      :co:`USE_SRC_MAPPING` is in effect, this will be taken into account to
      override the source TargetName.

-  .. co:: FORCE_360
      :choices: YES, NO
      :default: NO

      Whether to force longitudes in the [0, 360] range.

-  .. co:: WRITE_BOUNDING_DEGREES
      :choices: YES, NO
      :default: YES

      Whether to write Min/MaximumLong/ Latitude values.

-  .. co:: BOUNDING_DEGREES
      :choices: <min_long\,min_lat\,max_long\,max_lat>

      Manually set bounding box (values will not be modified by
      :co:`LONGITUDE_DIRECTION` or :co:`FORCE_360` options).

-  .. co:: USE_SRC_LABEL
      :choices: YES, NO
      :default: YES

      Whether to use source label in ISIS3 to ISIS3 conversions.

-  .. co:: USE_SRC_MAPPING
      :choices: YES, NO
      :default: NO

      Whether to use Mapping group from
      source label in ISIS3 to ISIS3 conversions. Defaults to NO (that is
      to say that the content of Mapping group will be created from new
      dataset geotransform and projection). Only used if :co:`USE_SRC_LABEL=YES`

-  .. co:: USE_SRC_HISTORY
      :choices: YES, NO
      :default: YES

      Whether to use the content pointed by
      the source History object in ISIS3 to ISIS3 conversions, and write it
      to the new dataset. Only used if :co:`USE_SRC_LABEL=YES`.
      If :co:`ADD_GDAL_HISTORY` and :co:`USE_SRC_HISTORY` are set to YES (or
      unspecified), a new history section will be appended to the existing
      history.

-  .. co:: ADD_GDAL_HISTORY
      :choices: YES, NO
      :default: YES

      Whether to add GDAL specific history
      in the content pointed by the History object in ISIS3 to ISIS3
      conversions. Only used if :co:`USE_SRC_LABEL=YES`. If
      :co:`ADD_GDAL_HISTORY` and :co:`USE_SRC_HISTORY` are set to YES (or unspecified),
      a new history section will be appended to the existing history. When
      :co:`ADD_GDAL_HISTORY=YES`, the history is normally composed from current
      GDAL version, binary name and path, host name, user name and source
      and target filenames. It is possible to completely override it by
      specifying the :co:`GDAL_HISTORY` option.

-  .. co:: GDAL_HISTORY

      Manually defined GDAL history. Must be
      formatted as ISIS3 PDL. If not specified, it is automatically
      composed. Only used if :co:`ADD_GDAL_HISTORY=YES` (or unspecified).

Examples
--------

How to create a copy of a source ISIS3 dataset to another ISIS3 dataset
while modifying a parameter of IsisCube.Mapping group, by using GDAL
Python :

::

   import json
   from osgeo import gdal

   src_ds = gdal.Open('in.lbl')
   # Load source label as JSon
   label = json.loads( src_ds.GetMetadata_List('json:ISIS3')[0] )
   # Update parameter
   label["IsisCube"]["Mapping"]["TargetName"] = "Moon"

   # Instantiate new raster
   # Note the USE_SRC_MAPPING=YES creation option, since we modified the
   # IsisCube.Mapping section, which otherwise is completely rewritten from
   # the geotransform and projection attached to the output dataset.
   out_ds = gdal.GetDriverByName('ISIS3').Create('out.lbl',
                                                 src_ds.RasterXSize,
                                                 src_ds.RasterYSize,
                                                 src_ds.RasterCount,
                                                 src_ds.GetRasterBand(1).DataType,
                                                 options = ['USE_SRC_MAPPING=YES'])
   # Attach the modified label
   out_ds.SetMetadata( [json.dumps(label)], 'json:ISIS3' )

   # Copy imagery (assumes that each band fits into memory, otherwise a line-by
   # line or block-per-block strategy would be more appropriate )
   for i in range(src_ds.RasterCount):
       out_ds.GetRasterBand(1).WriteRaster( 0, 0,
                                           src_ds.RasterXSize,
                                           src_ds.RasterYSize,
                                           src_ds.GetRasterBand(1).ReadRaster() )
   out_ds = None
   src_ds = None

See Also
--------

-  Implemented as :source_file:`frmts/pds/isis3dataset.cpp`.
-  :ref:`GDAL PDS Driver <raster.pds>`
-  :ref:`GDAL ISIS2 Driver <raster.isis2>`
