[Gdal-dev] 16 color TIFFs; buffering

[Matej Dular]

Hello! I'm using GDAL for some months now so more or less I am still a newbi. I have two technical questions and hope you don't mind sending them in one single mail.

1. TIFFs: If a TIFF image is saved with an indexed palette of 256 colors, GDAL handels it as such (1 band, 256 color palette). But if a TIFF image is saved with an idexed palette of only 16 colors, GDAL handels it as 4 band RGB (unindexed!) color image. This seems strange to me, isn't it?

2. Buffering. GDAL bufferizes image data while reading it by RasterIO so next reading of same image blocks is quite faster than the first one. I'm asking myself is there any way (and any sense) to disable buffering to improve GDAL performance when no repeated reading of the same image is planed? I only have to read an image grid at once and that's it. Buffering seems like an activity that is not really needed in such a case, and could theoretically slow down the task.

Thanx!

Matej
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