Advantech VisionNavi User Manual page 44

Convert the detection result to the specified unit with the mm / pix information set with
the camera setting tool. Optical flow
When isotropic algorithm is selected
When an anisotropic algorithm is selected
Detection result
Each item of the detection result can be used for judgment of this tool.
[Num matches]
It is the number of moving objects detected.
[Area]
It is the area of moving objects detected.
[Center X,Y]
The center coordinates of the detected moving object.
[Angle]
The moving direction of the detected moving object.
[Moving amount]
The amount of movement of the detected moving object.
[Moving amount X, Y]
It is a value in the X direction and Y direction of the movement amount of the
detected moving object.
With this tool, moving objects are detected by calculating corresponding feature
points from two target images. If the amount of movement is large and feature points
can not be obtained in the previous and next images (there is no overlap), the moving
object can not be detected. Gray scale binarization area
2.6 Presence / Count
Gray scale binarization area
Binarize the image in the target area, calculate the feature quantity such as the num-
ber, position, shape etc. of the obtained area and make the judgment.
Detect condition
[Binarization]
There are five ways to determine the threshold of binarization.
Manual ·········Set high and low thresholds directly. The threshold can also be set by
mouse dragging the threshold line of the brightness histogram.
Auto_Light ····Consider the overall brightness for each image and automatically set
the threshold value. Detects the bright part of the image. As shown in the example in
the above figure, it can be effectively used when the lighting condition of the image is
different.
Auto_Dark ····Same as Auto_Light, the threshold value is set automatically for each
image. Detects the dark part of the image.
MSER_Light ·MSER?Maximally Stable Extremal Regions?By using the region seg-
mentation method, threshold setting is done automatically, then bright parts are
detected for the surroundings.
MSER_Dark ··Same as MSER_Light, threshold setting is done automatically, then
dark parts are detected for the surroundings. Gray scale binarization area
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[Threshold High, Low]
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