Photon Focus DR1-D1312(IE)-G2, User Manual

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4 Functionality
4.8.2 Gamma
The ’Gamma’ mode performs an exponential amplification, configurable in the range from 0.4
to 4.0. Gamma > 1.0 results in an attenuation of the image (see Fig. 4.45), gamma < 1.0 results
in an amplification (see Fig. 4.46). Gamma correction is often used for tone mapping and
better display of results on monitor screens.
0 200 400 600 800 1000 1200
0
50
100
150
200
250
300
Grey level transformation − Gamma: y = (255 / 1023
γ
)
⋅
x
γ
(
γ ≥
1)
x: grey level input value (10 bit) [DN]
y: grey level output value (8 bit) [DN]
γ
= 1.0
γ
= 1.2
γ
= 1.5
γ
= 1.8
γ
= 2.5
γ
= 4.0
Figure 4.45: Applying gamma correction to an image (gamma > 1)
0 200 400 600 800 1000 1200
0
50
100
150
200
250
300
Grey level transformation − Gamma: y = (255 / 1023
γ
)
⋅
x
γ
(
γ ≤
1)
x: grey level input value (10 bit) [DN]
y: grey level output value (8 bit) [DN]
γ
= 1.0
γ
= 0.9
γ
= 0.8
γ
= 0.6
γ
= 0.4
Figure 4.46: Applying gamma correction to an image (gamma < 1)
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