
Algebra of vectors and matr ices 11
1.3 Algebra of vectors and matrices
It is very convenient, in fact essential, to use a vector representation for multi-
sp ectral or SAR image pixels. In this book, a pixel will be represented in the
form
g(i, j) =
g
1
(i, j)
.
.
.
g
N
(i, j)
, (1.4)
which is understood to be a column vector of spectral intensities or gray-scale
values at the image position (i, j). It can be thoug ht of as a point in N -
dimensional Euclidean space, commonly referred to as input space or feature
space. In the case of SAR images, the vector components may be complex
scattering a mplitudes.
Since we will be making extensive use of the vector ...