Once the significant wavelet coefficients have been detected, they can
be grouped into structures (a structure is defined as a set of connected
wavelet coefficients at a given scale), and each structure can be analyzed
independently. Interesting information which can be easily extracted
from an individual structure includes the first and second order moments,
the angle, the perimeter, the surface, and
the deviation of shape from sphericity (i.e. 
).
From a given scale, it is also interesting to count the number structures,
and the mean deviation of shape from sphericity.
In order to visualize the structures, we can create an image by plotting
a contour for each detected structure. This provides a compact way to visualize
the multiresolution support.
Figure 6 (click here) (left) shows the contours of the multiresolution
support of the simulated image of Sect. 4 (click here). Figure 6 (click here) (right) shows the contours of the same simulated
field, but the objects of the simulated noisy image contain less flux
(the maximum of the image is equal to seven counts), while the background is
the at the same level (0.1 count per pixel). We can easily see that in
this case, the two point sources have disappeared. Both detection were
done with 
.