Image Processing Reference
In-Depth Information
Fig. 2.1
Illustration of different levels of image fusion
niques can further be distinguished, depending on whether the images are fused in
the spatial domain, or in the transform domain. The pixel-level fusion in the spatial
domain is considered as a local operation where the individual pixels are processed
to form the pixels of the fused image. The transform domain techniques, however,
generate a fused image globally. The change in a single coefficient of the transformed
image can reflect into a global (image-level) change in the output. This may lead to
some undesirable effects in the fused image [205].
A large number of pixel-based techniques which span a whole plethora of appli-
cations have been proposed over the years. Some of these techniques have proved
to be very successful even across multiple application domains. The scope of this
