Extract Gabor transform coefficients or wavelet at a specified level, voice, and angle from transform or wavelet list.
DESCRIPTION:
This is a utility function for the Gabor wavelet transform. Given the result
from wavGabor or wavGaborWavelet, extracts a specific matrix from the
result list. This is helpful to visualize the transform or inspect a specific
wavelet at a given level, voice, and angle of rotation.
the list of matrices returned by either wavGabor or wavGaborWavelet.
level
the desired level to pick out of the list.
voice
the desired voice to pick out of the list.
angle
the desired angle to pick out of the list.
DETAILS:
This function takes the values of the level, voice , and angle as indexes, not
actual values: level = 1, voice = 2, angle = 3 means the third rotation of the
second voice of the first level.
SEE ALSO:
EXAMPLES:
# 2 levels, 3 voices, 3 angles of rotation
# starting a pi/4, separated by pi/8
out1 <- wavGaborWavelet(nlevels=2, nvoices=3, nangles=3, angle.init=pi/4, angle.step=pi/8)
# examine the wavelet at second level, third voice, first angle
out2 <- wavGaborExtract(out1, level=2, voice=3, angle=1)
trellis.device()
persp(Re(out2))