Routines (alphabetical) > Routines: H > HDF Routines > HDF_GR_SETCOMPRESS

# HDF_GR_SETCOMPRESS

This function specifies the type of compression for the specified HDF GR raster image.

## Syntax

Result = HDF_GR_SETCOMPRESS(ri_id, comp_type, comp_prm)

## Return Value

Returns SUCCEED (0) if successful or FAIL (-1) otherwise.

## Arguments

### ri_id

Raster image identifier returned by HDF_GR_CREATE or HDF_GR_SELECT.

### comp_type

Compression method for the image data. Valid values are:

- 0 = no compression
- 1 = RLE run-length encoding
- 3 = Skipping Huffman compression
- 4 = GZIP compression
- 6 = JPEG compression

### comp_prm

Compression parameters. If Skipping Huffman is used, set comp_parm to the skipping size (the size in bytes of the data elements). If GZIP compression is used, set comp_parm to an integer ranging from 1 (fastest) to 9 (most compressed).

## Keywords

None

## Version History

5.2 | Introduced