Oh yes, I checked those several ties.

While I was not able to read lines then write columns, I am having better luck reading columns then writing lines.

But, Frank seemed to think that the software might be inefficient accessing columns. He certainly was right - glacier creep is faster this. I will have to come up with something else, but it certianly has been a learning experience.

On 6/22/2011 9:51 AM, Chaitanya kumar CH wrote:
Paul,

Please check that you used the right values for XSize and YSize.

On Wed, Jun 22, 2011 at 6:39 PM, Paul Mallas <[email protected]
<mailto:[email protected]>> wrote:

    Yes, I tried this. I keep getting a segmentation fault doing it this
    way.

    I will dig further, maybe something else is not right.

    Regards,
    Paul


    On 6/17/2011 6:25 PM, Paul Mallas wrote:

        On 6/17/2011 5:41 PM, Frank Warmerdam wrote:

            On 11-06-17 03:23 PM, Paul Mallas wrote:

                Hello,

                I am trying to transpose image data (i.e., swap lines
                and columns)
                and am
                struggling to make it work properly. I think this should
                be possible
                through
                RasterIO, but so far no luck. Any suggestions?

                My approach so far has been like this, with image nXsize
                by nYsize:

                void *pData = VSIMalloc2(nXSize,
                (GDALGetDataTypeSize(eType) / 8));

                for (int iLine = 0; iLine < nYSize; iLine++) {

                // Read in row (line)
                eErr = poSrcBand->RasterIO(GF_Read, 0, iLine, nXSize, 1,
                pData,
                nXSize, 1, eType, 0,0);

                // Now I want to write a column, nothing I tried here
                has worked
                eErr = poDstBand->RasterIO(GF_Write, .......


            Paul,

            You should be able to write this column wise like:

            poDstBand->RasterIO( GF_Write, iLine, 0, 1, nXSize,
            pData, 1, nXSize, eType, 0, 0 );

            Note that this can be pretty inefficient depending on the
            format and
            how it is blocked.

            Best regards,


        Hmm, I thought I tried this configuration. I will try again.
        Thank you
        for your time Frank.



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--
Best regards,
Chaitanya kumar CH.
/tʃaɪθənjə/ /kʊmɑr/
+91-9494447584
17.2416N 80.1426E



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