Jorge Arévalo wrote:
In MEM driver page: http://www.gdal.org/frmt_mem.html says:
"PIXELOFFSET: Offset in bytes between the start of one pixel and the
next on the same scanline. (optional)"
The data pixels are bytes, but the pixeloffset is 2. I suppose in the
example, the data pixels are interlaced (one scan line starts on
pabyBigMem and the other in pabyBigMem + 1), and for this reason
pixeloffset = 2.
How do you specify this (if pixels are interlaced or not) when
creating the raster and adding the bands? Maybe this is not necessary,
and you specify this when reading or writing, but then, why in
GDALDatasetRasterIO the pixeloffset and lineoffset are set to 0?
Jorge,
To address such an existing array, the options to GDALAddBand()
would need to include DATAPOINTER, PIXELOFFSET and LINEOFFSET.
DATAPOINTER for the first call to addband would be pabyBigMem
and it would be pabyBigMem+1 for the second band. In both
cases PIXELOFFSET would be 2 and LINEOFFSET would be
PIXELOFFSET*(image_width_in_pixels).
Best regards,
--
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I set the clouds in motion - turn up | Frank Warmerdam, [email protected]
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush | Geospatial Programmer for Rent
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