Instruction manual

Guppy PRO Technical ManualV4.1.0
114
Description of the data path
Color interpolation (Bayer demosaicing)
The color sensors capture the color information via so-called primary color (R-G-
B) filters placed over the individual pixels in a Bayer mosaic layout. An effective
Bayer  RGB color interpolation already takes place in all Guppy PRO color
version cameras.
In color interpolation a red, green or blue value is determined for each pixel. An
Allied Vision proprietary Bayer demosaicing algorithm is used for this interpola-
tion (2x2), optimized for both sharpness of contours as well as reduction of false
edge coloring.
Color processing can be bypassed by using so-called RAW image transfer.
RAW mode is primarily used to
• save bandwidths on the IEEE 1394 bus
• achieve higher frame rates
• use different Bayer demosaicing algorithms on the PC (for all Guppy PRO
models the first pixel of the sensor is RED).
In color interpolation a red, green or blue value is determined for each pixel.
Only two lines are needed for this interpolation:
Figure 61: Bayer demosaicing (example of 2x2 matrix)
Note

If the PC does not perform Bayer to RGB post-processing, the
b/w image will be superimposed with a checkerboard pattern.
Figure 62: Bayer demosaicing (interpolation)
x
R1 G1 R2 G2
G3 B1 G4 B2
P1 P2 P3
Input:
Output: