Fig. 6.

Histogram plots of the channel outputs with anatomical variability and without signal variability. The axes are as described in Fig. 4. The columns represent the outputs from the six channels defined in Fig. 3. The rows are histogram plots for the cases of (a) the two male phantoms with different sizes, (b) two different genders, and (c) all 54 phantoms. The histograms in rows (a) and (b) used 16 bins while those in row (c) used 64 due to the larger number of feature vectors.