Image Processing Reference
In-Depth Information
Fig. 4.3 Three examples of gray-level mapping. The top image is the input. The three other images
are the result of applying the three gray-level mappings to the input. All three gray-level mappings
are based on Eq. 4.1
Fig. 4.4 If a in Eq. 4.2 is one, the resulting image will be equal to the input image. If a is smaller
than one then the resulting image will have decreased contrast, and if a is higher than one then the
resulting image will have increased contrast
them and we will say the contrast is high . The contrast of an image is changed by
changing the slope of the graph 1 :
1 In practice the line is not rotated around ( 0 , 0 ) but rather around the center point ( 127 , 127 ) , hence
b =
a) . However, for the discussion here it suffice to say that b =
127 ( 1
0 and only look at the
Search WWH ::

Custom Search