Tennis Camera, measure your serve speed

Discussion in 'iOS Apps' started by tenniscamera, Aug 15, 2014.

  1. tenniscamera macrumors newbie

    Joined:
    Aug 15, 2014
    #1
    Hello,


    If you are a tennis player you cannot miss this incredible App!!
    Tennis Camera is the first fully automatic tool to measure your serve speed with your iPhone as in a professional tournament!
    Save hundreds of dollars and put an incredible tool in your pocket!

    What it does?
    Tennis Camera does three unique things:

    • Like a professional radar it automatically measures your Serve Speed and reconstruct the 3D trajectory of your shot;
    • It tells you whether your serve was IN or OUT like a professional Hawk Eye;
    • Helps you to track your improvements by logging all your results.

    How it works
    We put together a bunch of technologies ranging from advanced computer visions algorithms, computational physics and the latest advancement in sport science to provide you a unique experience that all tennis players were waiting for!!

    How to use it
    It's super simple! Just start the Tennis Camera, turn your device into landscape mode, stand along the serve line and point the camera on the serving area: once your mate will serve you'll see a stunning animation full of details like the serve speed, the travelled distance, the time of flight and the 3D trajectory of your serve.

    Limitations
    Currently works only with iPhone 5, 5C and 5S. We're currently working to add support for iPads (Air).

    Check out our videos on our homepage and let us know what you think about it!

    http://bit.ly/1jFEygM
    https://www.youtube.com/watch?v=4ey7dMMNhOI
     
  2. tenniscamera thread starter macrumors newbie

    Joined:
    Aug 15, 2014
    #2
    Tennis Camera was updated to version 1.5.

    We improved the speed measurement algorithm and added an accuracy indicator in the result view.

    Have fun and serve aces!
     
  3. TouchMint.com macrumors 68000

    TouchMint.com

    Joined:
    May 25, 2012
    Location:
    Phoenix
    #3
    This is pretty interesting since most of the speed/"radar" apps use distance traveled over time to calculate an average speed. These actually can be accurate but are dependent on being very a accurate on the pressing of the start and stop button (timing).

    have you tested your app against some of these I would be interested to see the results and if positive it would be a great selling point in your app descrip.


    Note: I do make a speed app for baseball pitching speed.
     
  4. tenniscamera thread starter macrumors newbie

    Joined:
    Aug 15, 2014
    #4
    Dear TouchMint,

    You are completely right: the time lapse method is highly prone to time keeping errors in the order of 100ms. You can read more about it here (http://en.wikipedia.org/wiki/Fully_automatic_time).
    As the time of flight is in the order of 500-600 ms it automatically translates into errors in the order of 15-20%. This is just due to variations in timekeeping. On top of that you should also add the errors due to space measurement (ie: the overall ball's travelled distance). Finally the average the average speed is not the initial speed (the one measured in professional tournament) - but this last error could be somehow squeezed with some simple rules.

    Our technology uses many other parameters that were characterized with field tests or based on the available literature and the result is quite impressive. As a matter of fact we did much more than comparing the result of the low accuracy method you mentioned in your comment: all results have been compared to professional radars and show accuracy <5% (most of the times it is <3% !). In a few days we should publish a quite detailed post covering the high level architectures and main challenges we faced.

    We'll be happy to hear about your project: feel free to contact us at our email contact info @ tenniscamera dot com!
     
  5. tenniscamera thread starter macrumors newbie

    Joined:
    Aug 15, 2014
    #5
    We just released Tennis Camera 1.7 adding iPhone 6 and 6 Plus support.
     
  6. tenniscamera thread starter macrumors newbie

    Joined:
    Aug 15, 2014
  7. FeliApple macrumors 6502

    Joined:
    Apr 8, 2015
    #7
    Downloaded the free version, and it didn't work for me. It detected the court, when the ball passed, it did nothing. Tried it like 20 times, bc I know that the free version measures 1 every 4 serves. Also, the battery drainage was incredible. It went from 100% to 90% in 15 minutes, and it is not the phone, it's the App, bc zi recharged the phone and it went from 100% to 90% in one hour.
     
  8. tenniscamera thread starter macrumors newbie

    Joined:
    Aug 15, 2014
    #8
    What iPhone are you using?

    The most important trick to get a successful measurement is to stand still as much as possible. This is usually all you need to get consistent measurements. Try to lean against the protection fences or ideally try to lay the device on a flat surface without holding the device in your hands. Pointing direction is also important: try to point in the direction that maximizes the trajectory of the ball before the bounce.

    Let us know if these tips helps you out.
     
  9. FeliApple macrumors 6502

    Joined:
    Apr 8, 2015
    #9
    Is it possible that the App doesn't work at night?
     
  10. tenniscamera thread starter macrumors newbie

    Joined:
    Aug 15, 2014
    #10
    Under artificial lighting conditions it's vey important so select the correct Utility frequency (Settings > Utility Frequency). If you allowed Tennis Camera to access your GPS location it will be automatic, otherwise you'll need to make sure to select the correct one manually.

    Low light conditions make detection even tougher and it's even more important to stand really still during detection. Did you try the trick to lean against the court fences?

    What device are you using? Send us a screenshot of TC while you're pointing the court. We could checkout if you're pointing in the ideal direction and get an idea if lighting is enough for the app to produce a result.
     
  11. FeliApple macrumors 6502

    Joined:
    Apr 8, 2015
    #11
    I am using an iPhone 5s, I will try again using your tips, and send you a screenshot. Thank you for your patience.
     

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