Hi Gerd and Andrzej,
> your choice of triangle is arbitrary.
of course, but the version with 4 triangles isn't.
> bilinear interpolation seems better
Yes. It's a little bit more to calculate, but better. For our special case
it is:
h = h11 * (1 + y * x - x - y) + h21 * (x - y * x) + h12 * (y - y * x) +
h22 * y * x
(h11 is left-bottom in coordinate origin, the horizontal and vertical
distance is 1)
If your java-class have to much overhead, you can use this formula.
By the way, i would be very defensive with interpolation in the case of
missing values. The hgt values are only interpolated values from original
measurments. I would not interpolate values in the near of missing values.
That give us a nice but unreliably picture.
Frank
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