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New version of the Viewer can export headway data

We have recently released a new enhanced version of DataFromSky Viewer! You can download the demo package at the home page. The list of differences includes a lot of things, so let’s take a look at few of them.

New feature? Calculate and export headways!
Have a look on the picture below, how to display the headway data in the Viewer. It is important to have the gates set properly per each lane to get the most accurate data. Once you have all the gates defined, choose one gate in the Traffic Analysis Gates box and click on button “Show” in More Statistics option. In a newly opened window, there is possibility to click on Calculate headways. The system will automatically calculate headways for all defined gates in the video. The headway data can be exported to the CSV file, simply by clicking on “Export”.

Movement Dynamics Graph
We have visualized movement dynamics for each trajectory into a graph containing information about the vehicle’s speed and acceleration (total, lateral or tangential). This graph can be created for each selected trajectory.

Some other improvements…

  • Added option in CSV trajectory export to select time origin of the exported time stamps. Three options are available (the timestamp will be exported in accordance to the selected option):
    1. Start of Video Sequence
    2. Start of Tracking Log
    3. Start of Trajectory
  • Rewritten Gap-Time/Time-to-follow analysis to support better fine-tuned parameters
  • Added dialog for export of Gap-Time/Time-to-follow to enable user provided parameters for the analysis and export
  • Added manual (in pdf file) explaining the Gap-Time/Time-to-follow analysis
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    New version of Viewer

    We have a new version of Viewer! You can download it at the home page, or use this direct link. The list of differences includes a lot of things, so let’s take a look at them one by one.

    Gate angular sensitivity illustration

    Gate angular sensitivity

    Gates can count objects, and filter them based on their type. When we had to cope with chaos on the road in both directions, we added directionality. But sometimes all objects come chaotically from all directions, such as pedestrians. What then?

    We now added a new setting for gates, where it is possible to select the angles under which objects must come. If their direction falls outside this angular range, the gate will not register them. With this functionality it is possible to handle yet another level of chaos and uncertainty, should you chance to record such behaviour.

    On the left is a mock picture of the concept. Both gates have directionality set. The entry gate (15) has angular sensitivity of 90 degrees and the exit gate (7) has angular sensitivity of 15 degrees. Without directionality, the cones that depict the angle ranges would be on both sides. Note that angle of 90° means a right angle on both left and right: A bi-directional gate with angle of 90° (both default values) in fact accepts 180° on both sides, or 360°, and does not discriminate at all.

    distance_measurement

    Distance measurement

    Now, DataFromSky Viewer users can measure exact distances between two or more points – even if there’s no road. This function is particularly helpful for a traffic engineer. To start using the new distance measuring tool, right click on any point on the image, and select “add point”. Then define another point on the image in the same way, and you will see the distance between them.

    The precision depends on the quality of geo-registration procedure, but it is often better than 40 centimeters. The distances are showed in meters. You can also add multiple points to measure distances between them. If you make a mistake, select the point and move it on the right position.

    Difference between detected and actual vehicle center

    Vehicle center projection

    This is not a feature of Viewer, but yet another good news, so here we go! We silently added this in the last months and forgot to mention it. We now project vehicle definition points onto ground. Typically, they lie in the visual center, but not actual vehicle center. This may not seem like much of a difference, but we missed somewhere between 0.2 to 1 meter that way! More importantly, this error is not homogeneous in any practical way, only for vehicles of the same height at the same place. Given that we meticulously correct for perspective and other factors, losing so much precision was not an option – particularly now that we started systematic work on precision and error quantification and improvement.

    Improved load and playback speed

    Speed is something that one expects naturally from modern computers and software. This is not always possible with lots of visual data, as in our case, but not always impossible either! Now that we are working on (and with) Viewer in earnest, we focused on speed as well. Believe it or not, but sending numbers to show in the old vehicle list turned out to be a drag. Another thing that ended up significantly faster was drawing all the lines, shapes, notes, boxes and texts on top of the video. Apart from this we changed a lot how the Viewer handles video under the hood.

    We are confident that you will like how speedy the Viewer turned out, compared to how it was before!

    Other

    Apart from the visible things, many bugs were fixed.

    The default download link is for 64-bit Windows. If you need a 32-bit version, get this one instead.

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