Thanks Jay and Chaitanya, your comments helped a lot. I have few more doubts, these may be trivial but since i am new to GDAL i want to confirm.
1) Is it possible to cut a portion(AOI) of image in any format and store it as tiled GTiff. Cos i want to create multiple copied of image data as i keep editing them with different enhancements. and i want all the copies to be readily accessible in the form of tiles so that ram don't fill up too much. 2) When I read an image through ReadBlock() i had to allocate some memory and pass it in the function. Is there some way that i get the image data stored in GDALRasterBlock directly without passing my own allocated memory. Cos with this I would not have to write the buffer back using the WriteBlock(), and I can direclty change the block data improving the memory utilization. Thanks again, Akhy Hückelheim On Wed, Mar 28, 2012 at 12:20 AM, Jay L. <jzl5...@psu.edu> wrote: > For a geotiff I would use the following to change block size. > > gdal_translate -of GTiff -co "TILED=YES" -co "BLOCKXSIZE=256" -co > "BLOCKYSIZE=256" <input> <output> > > Replace 256with whatever integer you want. > > I realize that this is outside of your program, but it looks like you are > going to need to modify the input data pre-processing. > > > Jay > > > > On Tue, Mar 27, 2012 at 11:14 AM, akshay gupta > <akshaygupta...@gmail.com>wrote: > >> Hi, >> >> I have few questions regarding GDAL tiling and overviews. >> >> 1) Is there any In build direct function in GDAL from where i can set the >> size of the tiles(raster block size). >> 2)I an facing an strange situation. I have an TIFF image, and I am trying >> to read it block by block using ReadBlock(). When i read block from the >> band of the original dataset(GDALDataset I get when i call GDALOpen() ), I >> get a tile which is of size Width X 1 but if i create overviews and then >> call ReadBlock() on the band extracted from the first overview i get square >> tiles(Blocks). Can any body tell me why is this happening, Is there any way >> of getting square tiles of same size irrespective of whether i call >> ReadBlock() on original Dataset or on the overview level. >> >> Thanks and regards, >> Akhy Hückelheim >> >> _______________________________________________ >> gdal-dev mailing list >> gdal-dev@lists.osgeo.org >> http://lists.osgeo.org/mailman/listinfo/gdal-dev >> > >
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