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Fig. 8.3 Plots of PSNR of the fused images for various values of κ on the Hyperion and the AVIRIS
data using the bilateral filtering-based fusion technique over the subsets selected using the output-
based scheme. The resultant image from fusion of the entire dataset using the same technique is
used as a reference in each case
the reference image. Similar to the input-based band selection, the values of PSNR
drop very gradually when
65, this scheme selected 71
bands of the urban hyperspectral image which is nearly
is increased. For
κ =
/ 3 -rd the entire dataset,
however, the fused image provides a PSNR above 30 dB which indicates a good
visual match between the two images. For the same value of
, 110 bands of the
moffett 2 data were selected, yielding the corresponding fused image with a PSNR of
nearly 43 dB. A PSNR above 40 dB can be observed in the resultant image generated
from fusion of only 12 bands when the threshold parameter
is set to 0.70 in the
case of the moffett 2 hyperspectral image. This result compares very well with that
for the input-based band selection scheme shown in Fig. 4.5 . Therefore, both the
schemes of band selection provide a subset of bands which is capable of producing
comparable results with only a fraction of the data. Similar characteristic plots have
been observed for other pixel based fusion techniques also.
Although visual comparison is a subjective measure, it is often important, espe-
cially when the primary purpose of fusion is the visualization of scene contents by a
human analyst. We provide some of the output images resulting from fusion of sub-
sets of the moffett 2 hyperspectral image where the bands have been selected using
the output-based scheme. The fusion results of the output-based band selection are
provided in Fig. 8.4 . The images in Figs. 8.4 a-d are obtained from the subsets of
the moffett 2 data where the cardinality varies with relation to the variation in the
threshold parameter
. Figure 8.4 a shows the result of fusion of the entire dataset,
and thus it acts as the reference for the evaluation purpose. Figure 8.4 b is the result
of fusion of 142 bands by setting
the band selection scheme does not discard any of the input bands, and hence the
fused images obtained for the values of
to be 0.50. As for the values of 0
less than 0.40, are essentially the same
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