How To / Using Video Analysis

You can use the Video Analysis tool to create a graphical representation of the motion you see in a movie or picture*. This is ideal for mathematically analyzing real world events.

A tutorial covering video analysis is available. Select Open from the File menu, then look in the Experiments folder to access it.

Before you can analyze a video, you must add a movie to your page.

From the Insert menu, choose Movie and select the movie you want added to your page. Supported movie formats are Video clip (.avi) and QuickTime movies (.mov). These can be movies that you capture directly from a video input such as a digital video camera or web camera

Now you can set up your movie for basic analysis:

Click  in the movie player. The video analysis tools will appear on the right side of the movie player. A graph will also be displayed. See below. By default    the graph will display both the x and y positions versus time. If necessary, resize and move the graph to a desired position.

  1. Set a scale for the analysis. For this, it is important to have something in the movie to set the distance. You could include a meter stick in the movie to function as a reference. Click  then click and drag the mouse from one end of the reference to the other end. A pop-up dialog box will appear. Enter the Distance and the appropriate Unit for the object you are using. For example, for a meter stick, enter Distance-1, and Units-m.
  2. Click .
  3. Click the Play button, and just before the object in the movie begins its motion, click the Stop button. Click the Next Frame button and advance the movie until the object is in motion.
  4. Move the mouse over the movie and use the cross hairs to identify a recognizable point on the object.
  5. Click the mouse. A mark is left on the screen and the movie advances one frame.
  6. Repeat steps 5 and 6 until you have marked the point you want to analyze..
  7. Click the movie Play button to see the object move and the record of its horizontal and vertical position.
  8. The graph shows the object's horizontal and vertical positions vs. time. Use Logger Pro's various analysis features (including Curve Fits) to study the object's motion.
*Instead of marking one object across frames (time) as you would in a movie, analysis of a picture allows you to mark many points on one frame. This is useful in getting the points along a curve, for example.


See Also:

Video Analysis Overview

Video Capture