Hi, I have a large bitmap in memory, and I need to build overviews for this image and save them in TIFF format in an .ovr file. I could do this by saving the bitmap to disk (as a TIFF file), and then calling BuildOverviews with the path to the TIFF file, but this would use too much unnecessary IO which I cannot afford.
Now, I figured out how to use VSIFileFromMemBuffer to open my in-memory bitmap in GDAL without writing it to disk. However, according to my understanding of BuildOverviews (and correct me if I'm wrong), it will use the same driver that read the input to produce the output. I understand this means that when building overviews for a bitmap, the .ovr file will store the overviews as bitmaps. Is there any way to build overviews in TIFF format for a bitmap input, without having to convert the large image to TIFF format? Alternatively, can I perform the downsampling myself and only let GDAL manage the format of the .ovr file (by supplying the images for each pyramid level)? Thank you for your help! Yodan (C++, Windows, MSVC 2012, GDAL 1.9.1) -- View this message in context: http://osgeo-org.1560.x6.nabble.com/Building-TIFF-overviews-from-bitmap-in-memory-tp5202974.html Sent from the GDAL - Dev mailing list archive at Nabble.com. _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
