Motion

This module calculates the motion of an object, which means,the number of pixels that change from frame to frame for a path or contours.

How to use

1. Open the “Modules” tab and choose the “Motion” module.

2. On the top part select the video, the object and finally the object’s path or contour to determine the object you will calculate the motion for.

Note

You can preview the motion calculation by clicking on the name of thevideo you selected and then clicking on the ‘Play’ button under the video player

3. Use the blue slider or the left and right textboxes to select a start and an end frame for the calculation. The motion will then only be calculated for the specified interval.

Note

To change the start and end frame you also have to click on the name of the video, not just the checkbox

4. Use the “Compare with” selection box to choose how the motion is calculated:

- First frame -> compares the current frame with the first frame

- Previous frame -> compares the current frame with the previous frame (current frame - 1)

- Background image -> compares the current frame with a background image

To create a Background image you can either capture a frame or use the “Calculate the video background” module.

6. Use the “Threshold” slider to set the treshold for the motion

7. Use the “Radius” slider to select the radius the motion calculation

8. Check the “Show diffs boxes” if you want the preview to show the pixels that changed in the current frame

9. Press the “Apply” button to calculate the motion.

Result

The calculated motion will be added to the contours or path dataset as a new value called “motion”.

Example