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MAKE_CUBE

MAKE_CUBE
This is an image construction task which is able to produce a
filled image from one containing many blanked pixels. The reconstructed
filled image is not constrained to fit exactly the observed data points.
On the opposite, the construction is made by the analogy to a flexible
plate attached to fixed points by springs: the plate is the analogous
of the surface represented by the image, and the fixed points are the
analogous of the observed data points. By adjusting the parameter P
P = (plate stiffness) / (springs stiffness)
it is possible to control the fidelity to the original data and the
amount of smoothing involved in the image reconstruction. Low values of
P mean high fidelity to observed data, and negligible amount of
smoothing.
The original grid is first expanded by a factor EXPANSION$, new pix-
els being attributed the blanking value. Then, the minimization
proceeds iteratively to adjust the final image, until convergence is
reached. Initially blanked pixels are ignored in the convergence
criterium.
The algorithm works on cubes, processing each plane independently. It
can be used as an alternative to FILL_CUBE for oversampled images, but
works also for undersampled data.

Gildas manager
2020-09-28