# HF2 -- HF2/HFZ heightfield raster

(Available for GDAL >= 1.8.0)

GDAL supports reading and writing HF2/HFZ/HF2.GZ heightfield raster datasets.

HF2 is a heightfield format that records difference between consecutive cell values. HF2 files can also optionnaly be compressed by the gzip algorithm, and so the HF2.GZ files (or HFZ, equivalently) may be significantly smaller than the uncompressed data. The file format enables the user to have control on the desired accuracy through the vertical precision parameter.

GDAL can read and write georefencing information through extended header blocks.

## Creation options

- COMPRESS=YES/NO : whether the file must be compressed with GZip or no. Defaults to NO
- BLOCKSIZE=block_size : internal tile size. Must be >= 8. Defaults to 256
- VERTICAL_PRECISION=vertical_precision : Must be > 0. Defaults to 0.01

Increasing the vertical precision decreases the file size, especially with COMPRESS=YES, but at the loss of accuracy.

## See also

- Specification of HF2/HFZ format
- Specification of HF2 extended header blocks