Adept AdeptSight User Guide - Manual (Page 642)

Binary vs. Greyscale
Greyscale Representation of Sample Matrix
The algorithm that AdeptSight uses when looking at the three-by-three neighborhood of pix-
els allows edges to be located with sub-pixel accuracy. Thus, greyscale processing is generally
more accurate than binary processing.
Contrast
There are two settings that allow you to control the level of contrast in an image.
Gain
The sensors in the camera report an absolute intensity value. A camera operating in a low
light environment returns values in a limited range at the low end of possible values (0-127)
and the image would be very dark (similar to under-exposing a piece of photographic film). If
all the objects in the field of view reflect light of a uniform intensity, the values returned are
in a very narrow range. If the intensity values were multiplied by a given value, the relative
differences between intensity values would increase and edges would be easier to detect.
Gain is the AdeptSight parameter that performs this function.
Black Level
Similarly, if a given value, or offset, were added to all the pixels, the absolute brightness of
the image would increase, making it easier to work with. Black Level is the AdeptSight param-
eter that performs this function. If the value of Black Level is set too high, all the intensity
values are bunched up around the high end of the scale and the images are washed out (sim-
ilar to overexposing a piece of photographic film).
Using Gain and Black Level together allows you to maximize the brightness and contrast
within an image. The binary threshold values are calculated after the effects of Gain and
Black Level have been included in the image, so the difference between light and dark areas
of the image is maximized and the binary image is most useful. Exposure, Gain, and Black
Level can be set from the Edit window (within Acquisition Settings) of the Virtual Camera win-
dow.
AdeptSight User's Guide, Version 3.2.x, Updated: 8/23/2012
Page 642