Take the 2-minute tour ×
Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. It's 100% free, no registration required.

I'm fiddling around trying to create a thumbnail of a fairly large (originally 27MB) raster, chunked into 64x64 blocks. I've got the following and it works, quite well, but I'm wondering if there is a way to make it more efficient, or if it is just totally mental and shouldn't be attempted.

It suffers from various flaws - that it is not really so reusable, because it is quite specific, for example.

SELECT ST_AsPNG(ST_Reclass(ST_Union(rastnxn), 1, '[0-10]:1-65535', '16BUI', 0))
FROM (
        SELECT filename, ST_Resample(rast, 8, 8) as rastnxn
        FROM rasters 
        WHERE filename = 'someraster.tif'
) as subset
GROUP BY filename;

What do you think? Are there other (better) ways to quickly get the original raster back out in a 'thumbnail' style?

share|improve this question
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.