MI-Sins
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Fig. 2.16. Error 4 at the low video quality. Checking the cause is convenient in AR mode.
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Error 5
– due to nonuniformity lighting of the face (Fig. 2.17)
Fig. 2.17. Error 5 at the low video quality. Checking the cause is convenient in LD mode.
Error 1
The size of the person's head image in the picture elements (pixels), which determines the
accuracy of recorded vibrations, requires constant monitoring during testing. When tested with a
video image analysis there are no severe restrictions on the movement of the test person, as required
by the contact method. This person feels natural, which increases the accuracy of test results.
However, the natural behavior can lead to the fact that during the test response deviates from
the camera and the size of the human head image becomes less than required. To resolve this issue
vibraimage system constantly monitors a person's head size of the image and displays an error
message (1) in the window "QT" in the case of reducing the size below the limit. In addition,
vibraimage program includes a permanent face detection algorithm, which ensures elimination of
errors from a lack of a real image of the person in the frame during testing.
Error 2
Temporary noise signal from the video camera includes a video camera noise and illumination
instability and can significantly affect the test results. In this case, at the slightest noise level exceeds
the specified threshold, the system automatically displays an error message (2) in "QT" column.
Error 3
Despite the fact that the television camera may transmit to 30 frame/sec with the set resolution,
it does not guarantee that the computer receives and processes the incoming video data in real time.
And any deviation from the information processing in real time resulting in a loss of information and
hence reduce the reliability of the test. By reducing the actual input frames frequencies and processing
