about
The histogram is a vector containing the number of pixels with the same color (temperature)
ie. h(34)=22 means that there are 22 pixels with the color gray#34.
algorithm histogram function:
(1)
where:
M
horizontal image size (pixels)
N
vertical image size (pixels)
d
Dirac function (d(k)=1 for k=0, d(k)=0 else)
i
takes values in {0,1,.. , L-1} interval
L
the number of gray levels
example:
image
histogram
'reservoir' image
the histogram associated with the picture on the left tels this story:
- the picture has many 'dark' pixels
- most pixels have gray levels from 0 to 112 (11.4 degrees Celsius - 53.4 degrees)
- we have a maximum at gray level 0 (black) (11.4 degrees)
(1)