IDEC DATAVS2 Series - Manual (Page 37)

Instruction Manual SVS2 Series
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8.4.1. Position Locator
Description
It is also known as edge locator.
Edge: Border of object displayed.
This locator identifies the transition between:
• a light and a dark area (negative edge)
• a dark and light area (positive edge)
in the image under examination. For instance, picture a dark object on a light background: object
contour is identified as the edge, i.e. the set of dark pixels lying next to light pixels. However, it takes a
sharp tone variation for the light-to-dark transition to be interpreted as an edge; the extent of the
transition is determined by a threshold. (Edge detection ►)
Once the position of an edge has been set, it may be used as a parameter for the next controls
applied.
After the type of edge (positive/negative) to be identified has been specified, the locator processes the
ROI (in this case the plotted line) and stops as soon as it comes across an edge that meets set
specifications.
Selection
Pointer shape
Positioning
Click any point inside the work area to create a rectangular ROI with a small white square at the
bottom right corner.
To change ROI size, left-click and drag the square.
To move the ROI, place the pointer on any side of the ROI. The pointer changes to a cross. Press and
hold the left mouse button and drag the rectangle to the desired position.