[mkgmap-dev] HGT - getElevation()

Wed Jan 17 22:24:35 GMT 2018

Hi Gerd,

I have tried to verify, if aligned DEM is correct. I think algorithm 
have passed positively 2 tests:
- reading height from map gives correct values,
- changing bbox of source data doesn't change resulting map, even if it 
changes offset applied for aligning.

The aligning changes a bit shading, but it is difficult to decide which 
version better. Only your map of Bolivia suggested, that nonaligned 
version could be better. Maybe we should investigate this one?

For example we can oversample HGT using some good algorithm, like spline 
or lanczos, make unaligned map with oversampled HGT and compare changes 
in shadings?

-- 
Best regards,
Andrzej