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Adjust threshold
The Basic function detects if the image on the webcam has moved and initiates email sending and recording functions.
Whether or not the image reflected by the web camera has moved is determined by image processing using a statistical method.
The four methods are as follows.
・correlation
・Chi-squared
・Intersection
・Bhattachayyya distance
But you don't have to learn statistics.
You can easily find the right one by trying 4 different methods depending on the shooting location.
I will explain how to do that.
find and set the threshold
Click the button in the red frame to start shooting!
Click Basic
Click "Chi-square method" and "Continuous recording" as an example from the four methods.
※Ignore the other choices.
Other items are irrelevant if "Continuous recording" is checked.
Select the red frame and click "Select camera" to start shooting.
Confirm that the coefficient and the date and time are displayed at the bottom right of the screen. Repeat poses in motion and still poses facing the camera.
In this example, we will check the movement of an owl.
After several tens of seconds have passed, click the ✖ button on the upper right of the screen to close the screen.
When the shooting is over, the video is created in the folder below.
"C:\Users\{user name}\Documents\MiraiVision_ASURA\User"
If you carefully frame-by-frame this video, you'll find a factor of "2041.534038" exactly in frames per 3 seconds.
300 to 600 is common for other frames, and 2000 is a good threshold for moving images.
This time, the threshold was determined by the chi-square method, but other methods may provide better coefficients with a clearer difference.
Please try various things according to the shooting environment.
Once the threshold is decided, select the option in the red frame and enter it in the "Threshold" field.
And uncheck "Always record everything".
In this example, we want to detect when there is movement, so click "over", but conversely, if you want to detect when some device has stopped, click "or less".
After that, start shooting as before.
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