Description of the data path
MARLIN Technical Manual
V2.4.0
94
Binning (only Marlin CCD b/w models)
2 x binning
Definition
Binning
is the process of combining neighboring pixels while being read out
from the CCD chip.
Binning is used primarily for 3 reasons:
•
a reduction in the number of pixels and thus the amount of data while
retaining the original image area angle
•
an increase in the frame rate (vertical binning only)
•
an improvement in the signal to noise ratio of the image
Signal to noise ratio
(SNR) and
signal to noise separation
specify the qual-
ity of a signal with regard to its reproduction of intensities. The value signi-
fies how high the ratio of noise is in regard to the maximum wanted signal
intensity expected.
The higher this value, the better the signal quality. The unit of measurement
used is generally known as the decibel (dB), a logarithmic power level. 6 dB
is the signal level at approximately a factor of 2.
However, the advantages of increasing signal quality are accompanied by a
reduction in resolution.
Only Format_7
Binning
is possible only in video Format_7. The type of binning used
depends on the video mode.
Types
In general, we distinguish between the following types of binning
(H=horizontal, V=vertical):
•
2 x H-binning
•
2 x V-binning
and the full binning modes:
•
2 x full binning (a combination of 2 x H-binning and 2 x V-binning)
Note
L
Only
Marlin CCD equipped b/w cameras
have this feature.
Note
L
Changing binning modes involve the generation of new shad-
ing reference images due to a change in the image size.