[gdal-dev] CADRG/CIB GDAL Example

[Even Rouault]

Le mercredi 06 avril 2016 20:48:07, mlegge a écrit :
> I have spent some time trying to find an example of how to use GDAL to open
> CADRG/ADRG/CIB data.  I can find lots of information saying that GDAL
> supports these formats but no example on how to achieve this in GDAL.
> 
> We have sample apps where we load other types of data by calling GDALOpen
> and then using GDALWarpOperation (among other calls and they work well).
> For the CADRG we pass the A.Toc file to GDALOpen, however the A.Toc does
> not contain map data directly but rather a list of data subsets.  We use
> the MetaData available after the call to GDALOpen to call GDALOpen again
> followed by GDALWarpOperation.ChunkAndWarpImage for each of the data
> subsets.  However the ChunkAndWarpImage takes an extremely long time
> (hours) to complete making this approach unusable.

I assume that you need reprojection if you can ChunkAndWarpImage ? It 
shouldn't take hours if you only read a reasonable window of your dataset, but 
if you process the whole dataset and it is big, it can take a long time 
indeed.
And if you don't need reprojection, just use GDALDataset::RasterIO() or 
GDALRasterBand::RasterIO(). I can display fine CADRG datasets with QGIS for 
example.

> 
> It would be greatly appreciated if someone could point me to some sample
> code or give me some pointers on how to use CADRG withing GDAL.
> 
> Note that I am pretty much a newbie to GIS but I do have access to more
> experienced GIS developers.
> 
> Thanks
> Mel
> 
> 
> 
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