1 Topic by paulatc

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I am a competitive Olympic weightlifter and a Level 2 Olympic weightlifting coach with the USAW.  One thing that we study on our elite and mid-level weightlifters is the bar trajectory.  Until this software came along, I was drawing it by hand using a grid system.  Otherwise, I needed to use Dartfish which would have cost me over $1,000!  I have uploaded my bar trajectory to Youtube and linked it below.  The yellow path gives me a ton of information about that lift and this software made it incredibly easy to do.

http://www.youtube.com/watch?v=ytmuS28HpnE


One thing I would like to see added is the ability to calculate trajectory distances between 2 key frames.  I have done it in other software.  Since I use a tripod set perpendicular to the lifter, setting a scale is pretty easy, just calibrate the distance scale to the weight plate.  Weight plates in our sport are a standard 450mm.  Since the camera is stable and the bar is moving only vertically during the lift, accurate readings would be the norm.  It would really help the weightlifting coach to know the speed (which varies greatly during different phases of the lift) of the bar as it travels through the trajectory.

Thanks for the software!  I will be using it a lot.

2 Reply by joan

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Hi,
Thanks a lot for the feedback and the example video.

About coordinates, currently you can export them to spreadsheet documents. (A dialog window that would sum them up was considered but this is currently on hold.)

There are two things you may want to do before exporting,
1. Set the scale; place a line on a object of known length, then right click + "Seal measure" and input the length.
2. Set the coordinates origin; by default the origin point {0;0} is equal to the first point of the trajectory.
To set it to another point, right click on the trajectory + configure + "Coordinates system origin".

This will not really compute the distance between two points, but you may do that, and more, in the spreadsheet app.

Let me know if this work for you or how it could be made more straightforward etc…

3 Reply by joan

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I'm seeing more and more videos of weightlifting paths done in Kinovea popping up on internet here and there. That is great ! big_smile

I guess the next step (apart from displaying more infos on the path) would be to have an easy way to visually compare two or more bar paths together. And that would certainly be useful for other sports and activities.

So let's throw some ideas and have them incubate until this can turn into a nice handy feature smile
(We can save the data as .kva and reload in another video, but I think we could have something more dedicated/powerful)

4 Reply by metric

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joan wrote:

I guess the next step (apart from displaying more infos on the path) would be to have an easy way to visually compare two or more bar paths together. And that would certainly be useful for other sports and activities.

So let's throw some ideas and have them incubate until this can turn into a nice handy feature smile
(We can save the data as .kva and reload in another video, but I think we could have something more dedicated/powerful)

Yes, it would be very useful.
I wouldn't have thought saving and merging projects particularly onerous, but yes, if there is a way to make the comparison in one session that would be even better.

5 Reply by iroupa

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Dear Joan

I would like to apologize if someone else has already asked  this question but I didn´t found in the forum so I´m asking directly to you.
I´m trying to use the Coordinates System Origin feature to define an origin in a image, then I´m using the Cross Marker to mark some points (15) in that image. After that I want to repeat this process in several images and finally export the coordinates of each marker in each picture to a excel file. 
I would like to know if is this possible because I've tried to do it by myself but I'm not figuring it out how to do it.
Thank you in advance for your help

Ivo Roupa

6 Reply by joan

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It's not possible yet.
Currently only the lines and angles are exported (in addition to keyframes themselves, stopwatches and path tracks).
I'll try to add the markers in a future version.

7 Reply by iroupa

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Dear Joan,

Thanks for your answer.

I don´t know if you know "DigitizeXY31". It's pretty basic but it's what I use to get the markers coordinates for my biomechanic works. I don´t know if anyone else use it but since your software is much more advanced than DigtizeXY31 and since you introduced a Coordinate System Origin I though that would be possible to get all the work done with Kinovea.

Just one other though. Would it be possible to receive an email whenever someone answer to our post? Maybe someone had already ask it...

Anyway I will be waiting for next version of Kinovea 

Keep with your great job

Thank you in advance for your help

8 Reply by joan

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iroupa wrote:

Would it be possible to receive an email whenever someone answer to our post? Maybe someone had already ask it...

You can do that by using the "Subscribe to this topic" link above the quick reply box.

9 Reply by iroupa

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Thanks for your help.

Ivo Roupa