Rockwell Automation 5370-CVIM2 Module - Manual (Page 333)

5 Chapter Chapter 7
Inspection Tools
7–95
The Lut field in the tool edit panel selects a look–up table (LUT), which, as
noted earlier, remaps the gray scale values of the image pixels after all other
operations (except a
Morph 2 operation, if used) have been performed. Note
that the default LUT is Identity , which has no effect on the pixels.
When you pick the Lut field in the image tool edit panel, the Image LUT
selection panel appears as shown in Figure 7.78.
Figure 7.78 Accessing the Image LUT Selection Panel
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The selections in the Image LUT panel are described briefly, as follows:
•
Identity –– This selection has no effect on the image tool pixels.
•
Sign –– This selection adds 128 to the gray value of each pixel, which
converts a “signed” image (containing positive and negative gray values)
to an “unsigned” image (containing only positive gray values). The range
of values in the resulting image is 0 to 255.
•
Absolute –– This selection converts a “signed” image to an “unsigned”
image by using the absolute value of each pixel. The range of values in
the resulting image is 0 to 128.
•
Inversion –– This selection performs a “bit–wise” inversion of the gray
value of each pixel. Thus, 255 becomes 0, 85 becomes 170, –105
becomes +22, and so on.
•
Clip –– This selection forces the gray values of all pixels in an
“unsigned” image (maximum range: 0 to 255) to user–selectable high
and low range limits. Thus, all pixels whose original gray values lie above
(or below) the user–selected high (or low) threshold will be reset to a gray
value equal to the high (or low) threshold.
•
S.Clip –– This selection forces the gray values of all pixels in a “signed”
image (maximum range: –128 to 127) to user–selectable high and low
range limits. Thus, all pixels whose original gray values lie above (or
below) the user–selected high (or low) threshold will be reset to a gray
value equal to the high (or low) threshold.
Image Tool
Look–Up Table (LUT)