IDEC DATAVS1 Series - Manual (Page 55)

Instruction Manual SVS1 Series
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To modify the position of the ROI, move to the Move ROI icon and then press SET. It is now
possible to move the ROI using the ARROW buttons. Once you have achieved the desired
position, press the TEACH button to return to the Setup menu. If you wish to modify the ROI
size, select the Resize ROI from the Setup menu (using the SET button again). It is now possible
to increase or decrease the ROI size using the ARROW buttons.
• Parameters:
Min Width Expected
This indicates the minimum width threshold required to accept the inspected detail
Max. Width Expected
This indicates the maximum width threshold required to accept the inspected detail
• Sensitivity
Based on the first derivative of the pixel brightness variation function, the maximum positive peak
is identified if control is targeting a positive edge, or the maximum negative peak is identified
when targeting a negative edge. An edge feature is detected if the change in brightness is above
the set threshold, expressed according to the detected peak value.
• Variation type
It is possible to define the methods used to detect the edges. Possible values are:
From white to black: an edge feature is detected when a variation from white to black is
detected;
From black to white: an edge feature is detected when a variation from black to white is
detected;
Both: a feature is indicated as an edge feature when it changes from white to black and
black to white;
Automatic: the system automatically detects the edge features.
• Noise reject
This is used to reduce noise during the edge detection process. The threshold refers to the value
of the first derivative: it establishes the minimum variation in brightness of a feature in order for it
to be considered an edge.
• Direction
This determines the search direction of edges inside the ROI. This can be one of two values:
Horizontal (default value)
Vertical
• Measure type
This defines the direction when searching for edges to calculate the distance. Can be selected:
Internal: The search starts from the centre towards the outside
External: The search starts from the outside towards the centre