Thanks Jay and Chaitanya, your comments helped a lot.<br><br>I have few more doubts, these may be trivial but since i am new to GDAL i want to confirm.<br><br>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.<br>
<br>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.<br>
<br>Thanks again,<br>Akhy Hückelheim<br><br><div class="gmail_quote">On Wed, Mar 28, 2012 at 12:20 AM, Jay L. <span dir="ltr"><<a href="mailto:jzl5325@psu.edu">jzl5325@psu.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
For a geotiff I would use the following to change block size. <br><br> gdal_translate -of GTiff -co "TILED=YES" -co "BLOCKXSIZE=256" -co "BLOCKYSIZE=256" <input> <output><br><br>
Replace 256with whatever integer you want.<br>
<br>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.<span class="HOEnZb"><font color="#888888"><br><br><br>Jay<br><div><br></div></font></span><div>
<br><br><div class="gmail_quote"><div><div class="h5">
On Tue, Mar 27, 2012 at 11:14 AM, akshay gupta <span dir="ltr"><<a href="mailto:akshaygupta202@gmail.com" target="_blank">akshaygupta202@gmail.com</a>></span> wrote:<br></div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div><div class="h5">
Hi,<br><br>I have few questions regarding GDAL tiling and overviews.<br><br>1) Is there any In build direct function in GDAL from where i can set the size of the tiles(raster block size).<br>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.<br>
<br>Thanks and regards,<br>Akhy Hückelheim<br>
<br></div></div><div class="im">_______________________________________________<br>
gdal-dev mailing list<br>
<a href="mailto:gdal-dev@lists.osgeo.org" target="_blank">gdal-dev@lists.osgeo.org</a><br>
<a href="http://lists.osgeo.org/mailman/listinfo/gdal-dev" target="_blank">http://lists.osgeo.org/mailman/listinfo/gdal-dev</a><br></div></blockquote></div><br></div>
</blockquote></div><br>