1.. _raster.hf2:
2
3================================================================================
4HF2 -- HF2/HFZ heightfield raster
5================================================================================
6
7.. shortname:: HF2
8
9.. built_in_by_default::
10
11GDAL supports reading and writing HF2/HFZ/HF2.GZ heightfield raster
12datasets.
13
14HF2 is a heightfield format that records difference between consecutive
15cell values. HF2 files can also optionally be compressed by the gzip
16algorithm, and so the HF2.GZ files (or HFZ, equivalently) may be
17significantly smaller than the uncompressed data. The file format
18enables the user to have control on the desired accuracy through the
19vertical precision parameter.
20
21GDAL can read and write georeferencing information through extended
22header blocks.
23
24Driver capabilities
25-------------------
26
27.. supports_createcopy::
28
29.. supports_georeferencing::
30
31.. supports_virtualio::
32
33Creation options
34----------------
35
36-  **COMPRESS=**\ YES/NO : whether the file must be compressed with GZip
37   or no. Defaults to NO
38-  **BLOCKSIZE=**\ block_size : internal tile size. Must be >= 8.
39   Defaults to 256
40-  **VERTICAL_PRECISION=**\ vertical_precision : Must be > 0. Defaults
41   to 0.01
42
43Increasing the vertical precision decreases the file size, especially
44with COMPRESS=YES, but at the loss of accuracy.
45
46See also
47--------
48
49-  `Specification of HF2/HFZ
50   format <http://www.bundysoft.com/docs/doku.php?id=l3dt:formats:specs:hf2>`__
51-  `Specification of HF2 extended header
52   blocks <http://www.bundysoft.com/docs/doku.php?id=l3dt:formats:specs:hf2#extended_header>`__
53