matlab.io.hdf4.sd.getCompInfo
Namespace: matlab.io.hdf4.sd
Information about dataset compression
Syntax
[comptype,compparms] = getCompType(sdsID)
Description
[comptype,compparms] = getCompType(sdsID)
retrieves the compression type
and compression information for a dataset. comptype
can be one of the
following values.
'none' | No compression |
'rle' | Run-length encoding |
'nbit' | NBIT compression |
'skphuff' | Skipping Huffman compression |
'deflate' | GZIP compression |
'szip' | SZIP compression |
If comptype
is 'none'
or 'rle'
,
then compparms
is []
.
If comptype
is 'nbit'
,
then compparms
is a 4-element array.
compparm(1) | sign_ext |
compparm(2) | fill_one |
compparm(3) | start_bit |
compparm(4) | bit_len |
If comptype
is 'deflate'
,
then compparms
contains the deflation value, a
number between 0 and 9.
If comptype
is 'szip'
,
them compparms
is a 5-element array. Consult the
HDF Reference Manual for details on SZIP compression.
This function corresponds to the SDgetcompinfo
function
in the HDF library C API.
Examples
import matlab.io.hdf4.* sdID = sd.start('myfile.hdf','create'); sdsID = sd.create(sdID,'temperature','double',[100 50]); sd.setCompress(sdsID,'deflate',5); [comptype,compparm] = sd.getCompInfo(sdsID); sd.endAccess(sdsID); sd.close(sdID);