We suggest novel statistics for the CMB maps that are sensitive to
non-Gaussian features. These statistics are natural generalizations of the
geometrical and topological methods that have been already used in cosmology
such as the cumulative distribution function and genus. We compute the
distribution functions of the Partial Minkowski Functionals for the excursion
set above or bellow a constant temperature threshold. Minkowski Functionals are
additive and are translationally and rotationally invariant. Thus, they can be
used for patchy and/or incomplete coverage. The technique is highly efficient
computationally (it requires only O(N) operations, where N is the number of
pixels per one threshold level). Further, it allows to split large data sets
into smaller subsets. The full advantage of these statistics can be obtained
only on very large data sets. We apply it to the 4-year DMR COBE data corrected
for the Galaxy contamination as an illustration of the technique.Comment: 28 pages latex using aasms4 and epsfig. 11 postscript figures
embedded. Minor Changes, to reflect the published versio