Guerra, Francesco
warping that is softer but less easily controlled. In cartographic applications it is convenient to place the value of a as
always equal to 0.
The constant b determines in what way the influence of the vectors diminishes with the distance: if b=0 each pixel is
influenced in the same way; the usual values for 5 are inclusive between 0.5 and 3.
The value p is typically included in the interval (0,1): if p=0 all the vectors have the same weight, if p-1 the vectors
with a larger model will have a higher relative weight.
In the case in which a=0, p=0, b=1 the case from the preceding paragraph is reconsidered.
== eme
2 e.
c à
ii is Sie; 4
"E = e _ ^ 5
; 2 “I ^
i 7 s rm A > x X
fd lf SA MA
j 1 1 5 = E i
A2 00]
i AM. ^ 4 ; /
5 X . 7 Ë
^ D — sr, /
C NE d
A Fr ue Ne
cn D A b
figure8. A comparison between the distortions induced by a line of force and by the points that define it. Notice how the lines are
force allow the straight lines to be maintained. The homologous vectors allow for the definition of the rotations as well, where the
method using the points of force does not.
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