Image Processing Reference
In-Depth Information
B
Mathematical Definitions
This appendix provides some basic mathematical definitions. The appendix is in-
tended for readers who do not have a mathematical background or readers who
need a “brush-up”.
B.1
Absolute Value
The absolute value of a number, z , is written as Abs(z) or
|
z
|
. It is calculated by
deleting the “minus” in front of the number. This means that
|−
150
|=
150. Mathe-
matically the absolute value of a number, z , is calculated as
z 2
|
z
|=
(B.1)
In terms of programming it can be written as
if
(z < 0)
z=
1
z;
B.2
min and max
The min value of a set of numbers is written as min
{
x 1 ,x 2 ,...,x n }
and simply
means the smallest number in the set. For example, min
{
7 , 3 , 11 , 2 , 42
}=
2. The
max value of a set of numbers is written as max
{
x 1 ,x 2 ,...,x n }
and simply means
the biggest number in the set. For example, max
42. In terms of
programming the max operation can be written as follows, where we assume that N
numbers are present in the list and that they are stored in list
{
7 , 3 , 11 , 2 , 42
}=
[]
:
MaxValue= l i s t [ 0 ] ;
for
(i = 1;
i < N;
i = i+1)
{
if
( l i s t [ i ]
>
MaxValue )
MaxValue
=
l i s t [ i ] ;
}

Search WWH ::

Custom Search