Hi Gerd,
I'm trying to find if resolution can be better. I think current
interpolation is not good. Imagine two combination of 4-points heights
from HGT with values like:
1 0
0 7
and
0 1
7 0
For a point in the middle of rectangle, current interpolation would give
result 0 in first case and 4 in second, while I would expect 2 in both
cases.
I think the code, which calculates interpolation based on 3 points,
should be used only if the forth is void. There could be 3 combinations
of triangles in this case. But if all 4 points are valid, there should
be applied standard bilinear interpolation. Something like:
if (hlb == HGTReader.UNDEF) {
return triangle(...
}
if (hrb == HGTReader.UNDEF) {
return triangle(...
}
if (hlt == HGTReader.UNDEF) {
return triangle(...
}
if (hrt == HGTReader.UNDEF) {
return triangle(...
}
// 4 points valid
return bilinear(...
--
Best regards,
Andrzej
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