WWW.NNC.IR
Measurement Mechanism
839
8
Appendices
Vision System FH/FZ5 Series
User’s Manual (Z340)
Edge Detection Measurement
This method extracts parts with color changes as edges to perform measurement.
Edges are found through color changes in the measurement region.
Edge Detection Method
The following two types of edge detection method are available.
Projection (Density method)
A projected waveform is formed relative to the
density level. The intersection of the density and the
threshold (edge level) is detected as an edge.
With an image with high noise level or image with
blurry edges, the density method is suitable as it
allows you to specify the density and color of the
edges to be detected.
Derivation
A differential processing is performed to calculate
the change in density between neighboring pixels. A
differential waveform with the largest density set as
100% of the region is created, and the maximum
value (peak point) of the differential waveform that
exceeds the threshold (edge level) is detected as an
edge.
With an image with low contrast, the differential
method is suitable as it normalizes the differences
between the neighboring pixels for processing.
When calculating the X coordinate of this edge
Measurement
region
Edge level
Detection as an edge
255 170 133 70 20
0
255
Detection as an edge
(Density level)
Density
0
255
200
150
100
50
Differential value
(Change in density)
Density average
85 37 63 50
255 170 133 70 20
Change in density
Edge level
Detection as an edge
To Next Page
Loading...
Need help?
General
