**High Fidelity Compression of
Irregularly Sampled Height-Fields **

This paper presents a method to
compress irregularly sampled height-fields based on a multi-resolution
framework. Unlike many other
height-field compression techniques, no resampling is required so the original
height-field data is recovered (less quantization error). The method decomposes
the compression task into two complementary phases: an in-plane compression
scheme for (x, y) coordinate positions, and a separate multi-resolution z compression
step. This decoupling allows subsequent improvements in either phase to be
seamlessly integrated and also allows for independent control of bit-rates in
the decoupled dimensions, should this be desired. Results are presented for a
number of height-field sample sets quantized to 12 bits for each of x and y,
and 10 bits for z . Total lossless encoded data sizes range from 11 to 24 bits per
point, with z bit-rates lying in the range 2.9 to 8.1 bits per z coordinate.
Lossy z bit-rates (we do not lossily encode x and y) lie in the range 0.7 to
5.9 bits per z coordinate, with a worst-case root-mean-squared (RMS) error of
less than 1.7% of the z range. Even with aggressive lossy encoding, at least
40% of the point samples are perfectly reconstructed.