[gdal-dev] Effeciency of "ReadRaster" in different storage format of mulit-band image

[Frank Warmerdam]

On Thu, May 17, 2012 at 12:01 AM, hitweiran <hitweiran at sina.com> wrote:
> Hello, everyone.
> There are two methods to extract data from a mulit-band remote sensing image
> in GDAL.
> 1. Dataset.ReadRatser, that can read all data in mulit-band image.
> 2. Band.ReadRaster, that can read only one band of mulit-band image.
> Actually, there are three formats used to storage mulit-band image, BIL
> (Band Interleaved by Line format),BIP(Band Interleaved by Pixel format) and
> BSQ(Band Sequential format).
> Based on my test , the runtime of read whole mulit-band data is quite
> sensitive to the format of mulit-band image.
> For example, when I used "Band.ReadRatser" to read mulit-band image band by
> band. The total runtime is 285.93s, 13.48s and 19.51s for BIL, BSQ and BIP
> respectively; (the size of image: width*height*bands=501*1004*125). BSQ
> formate is the most effective.  However, the actual data can be storaged in
> any format, so,how can I solve this problem?

Hit Wei Ran,

You haven't really made clear what the problem is.  Is the problem
that some organizations of data give per performance?  What
actual format is being used.  There may well be cases we can
optimize if you can be more specific.

Best regards,

-- 
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Software Developer