
104 ◾ Lionel R. Watkins
e 2-D CWT of a signal f is then readily dened in an analogous manner
to the 1-D case:
θ=〈ψ 〉=
θ
−∗−
−θ
(,,) ,()( ())
,,
112
fafa
fa
xb x
b
(3.43)
Before we move on to consider some practical examples, there are several
aspects of the 2-D CWT that need to be discussed. First, a note about the
representation of this transform. e 1-D CWT takes a 1-D signal and pro-
duces a 2-D representation (scale and translation) that is easily plotted and
visualized. Here, we have taken a 2-D signal and produced a 4-D represen-
tation that cannot be readily plotted or visualized. Two approaches to this
visualization problem are discu ...