[Liblas-devel] Fast way to read compressed LAZ files

[Alexander Biddulph]

I am currently using liblas (with LASzip) to read compressed LAZ files.

My current workflow is to open the LAZ file, read in each point sequentially and place each point into a cell in a regular grid, then find the centroid of each cell.

However, this process is currently taking an extraordinarily long time, so I was wondering of there is some way that I could speed this process up.

I was initially thinking about extracting points from the file using multiple threads (via OpenMP). However, based on the small tutorials provided, it is my understanding that each thread randomly accessing the Nth point in the file would require decompressing the first N points. So I was then thinking about decompressing the entire file first, then randomly accessing the points in the decompressed file, however, I am unable to tell if this would actually provide much of a performance increase over just reading sequentially from the compressed file.

Can anyone suggest a good way of speeding this process up?

Thanks,
Bidski
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