[mkgmap-dev] HGT - getElevation()

Fri Jan 19 05:59:57 GMT 2018

Hi Andrzej,

I'd prefer to use unmodified dem-dist values for now, besides that the unit tests don't compile with it.
After adding 0.01 as new parm some tests fail.
Probably not so important, as the unit test HGTConverterTest is bad anyway, it tests non-public methods
and your patch shows that this is a bad idea.

Gerd

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Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von Andrzej Popowski <popej at poczta.onet.pl>
Gesendet: Freitag, 19. Januar 2018 02:59:14
An: mkgmap-dev at lists.mkgmap.org.uk
Betreff: Re: [mkgmap-dev] HGT - getElevation()

Hi Gerd,

I have prepared patch according to these guessed rules. It rounds
dem-dist and shift coordinates of top-left corner of DEM areas. Since
dem-dist doesn't correspond exactly to HGT, interpolation is always active.

I think there could be 2 ways to improve DEM quality. Interpolation
could be changed to bicubic or mkgmap could use preprocessed data with
correct pixel size. In the latter case probably data format other than
HGT should be used.

--
Best regards,
Andrzej