Guppy PRO Technical Manual
V4.1.2
119
Hue and saturation
Guppy PRO CCD and Guppy PRO F-503 color models are equipped with
hue
and
saturation
registers.
The
hue register
at offset 810h allows the color of objects to be changed
without altering the white balance, by +/- 40 steps (+/- 10°) from the nominal
perception. Use this setting to manipulate the color appearance after having
carried out the white balance.
The
saturation register
at offset 814h allows the intensity of the colors to be
changed between 0 and 200% in steps of 1/256.
This means a setting of zero changes the image to black and white and a setting
of 511 doubles the color intensity compared to the nominal one at 256.
Color correction
Why color correction?
The spectral response of a CCD is different from those of an output device or
the human eye. This is the reason for the fact that perfect color reproduction
is not possible. In each Guppy PRO camera there is a factory setting for the
color correction coefficients, see
Color correction is needed to eliminate the overlap in the color channels. This
overlap is caused by the fact that:
•
Blue light:is seen by the red and green pixels on the CCD
•
Red light:is seen by the blue and green pixels on the CCD
Formula 4: Bayer demosaicing
Note
Configuration
To configure this feature in feature control register: See offset
on page 209 and
Note
Configuration
Hue and saturation
do not show any effect on Guppy PRO
color models in the Raw8 and Raw16 format, because color
processing is switched off in all Raw formats.
P1
red
R1
=
P1
green
G1
G3
+
2
-------------------
=
P1
blue
B1
=
P2
red
R2
=
P2
green
G1
G4
+
2
-------------------
=
P2
blue
B1
=
P3
red
R2
=
P3
green
G2
G4
+
2
-------------------
=
P3
blue
B2
=
