Instruction manual

Glossary
PIKE Technical Manual V3.1.0
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Square pixel Pixels of the same x and y dimensions (pixel aperture ratio PAR = 1). In the
case of rectangular (non-square) pixels (usual in TV) one must maintain
the aspect ratio when measuring objects, because the dimensions of stored
frames aren't equal to true dimensions; resolutions along x and y axes
aren't the same. Use of square pixels solves such problems - picture ele-
ments are equally arrayed in both directions, and allow easy addressing.
Thus aspect ratio of the image does not require adjustment. This is needed
in image processing tasks requiring accurate image measuring.
Aspect ratio: The ratio of horizontal to vertical dimension of the illumi-
nated sensing area.
Pixel aperture dimension ratio: Defines the pixel dimension (the ratio of its
width to height). This parameter describes the resolution (granularity) and
the reproduction behavior of an image sensor area.
Aspect ratio deviation: Shows the ratio between frame store data and true
dimensions of an image.
Sub-sampling Sub-sampling is the process of skipping neighboring pixels (with the same
color) while being read out from the CMOS or CCD chip.
CMOS equipped MARLIN models, both color and b/w have this feature (FW
> 2.03).
E.g. the CCD model MARLIN F-146C is also equipped with this mode, acting
as a preview mode. Because it is realized digitally there is no further speed
increase.
Sub-sampling is used primarily for 2 reasons:
• A reduction in the number of pixels and thus the amount of data
while retaining the original image area angle and image brightness
• CMOS: an increase in the frame rate.
Similar to binning mode the cameras support horizontal, vertical and h+v
sub-sampling mode.
Trigger Trigger is an input to an industrial digital camera than initiates the image
capture sequence. Otherwise, an electrical signal or set of signals used to
synchronize a camera, or cameras, to an external event.
The term trigger is sometimes used in the sense of a trigger shutter.
Trigger shutter A trigger shutter is a shutter mode with random timing or even with ran-
dom shutter speed. Such randomness is controlled by the trigger signal
mentioned above.
USB Universal Serial Bus (USB) provides a serial bus standard for connecting
devices, usually to computers such as PCs, but is also becoming common-
place on digital cameras.