The long jump rules were changed in 2021 to the jumper not crossing the vertical plane of the line on the board - using plasticine is not enough anymore, but the board should be checked by video. The available systems are pretty expensive, so i wondered if the Kinovea could be used for this:
A high quality smartphone or GoPro/clone with the highest possible resolution and 60+ fps connected by USB?

Kinovea is very handy when using the recording&playback screens, placing a virtual line to the board, recording the take-off and quickly swiping the clip to the playback, where one can zoom in at the details....and save the clip to be reviewed later if necessary.

The needed resolution is probably higher than HD (2K?) and fps 60-120?

Could this be achieved?


Yeah I followed this change, I find it a bit weird to be honest.
Is this change being implemented at all levels of competition?

I think it may be possible to do in Kinovea but probably there is a validation process by the federations.
Do we know what hardware and specs is used in the existing systems? I imagine this must be documented so federations and systems providers can comply.

There is also an undocumented "finish line" feature in the program that could help. It triggers for some machine vision cameras when configured for very few lines. This mode records the lines at high frequency and stack them to create "photo-finish" images and videos.

3 (edited by AlexanderH 2022-11-03 17:21:47)

HI Joan,

I tried out Kinovea "as is" and it could very nicely be configured to start a 1,5s video by the sound of impact on the board (a photo cell would be more secure in a noisy environment, of course), send the video to be played in slow motion by another instance of Kinovea on a second screen for visual check. I have drawn a line not to be crossed before the foot lifts off the board. With a ground contact time of 0,1-0,15 seconds, there will be 3-5 pictures at 30fps, 6-10 at 60fps, 10-15 at 100fps. An interpolated line of no crossing would increase the sensitivity...as well as higher resolution.

It is important that the video can be saved for the jury, in case there is a disputed jump.

As I know, the new rule has not yet been restricted to any age-groups - if there is a board, the jump should be judged by the new rule of foul.

Are you familiar with the android application Photo Finish, developed by the brothers Johann-Lukas and Arthur Voigt? They use two picture on both sides of an arbitrary line and count the pixels along the line to estimate the intermediate crossing.


Would a good trail camera with PIR, saving to the replay folder, by USB make this work....?


I've done this several times in competition.
We have a standard USB camera and an operator to start/stop the recording.
The analysis is done and saved in one PC and we have an external monitor available for the athletes with another instance of Kinovea with the replay Folder observer always open.
It works pretty nice and simple.
I've already posted some feature requests here:
https://www.kinovea.org/en/forum/viewto … 4713#p4713
https://www.kinovea.org/en/forum/viewto … 4718#p4718
https://www.kinovea.org/en/forum/viewto … 4710#p4710


Nice. I have been looking around for WebCam Surveillance software (motion detection) that save to the disk. The resolution, FPS and lag make the inferior so far......


Are you sure it has to be fully automated? Why not have the judge/secretary just pressing a button to record?


fernando.morais wrote:

Are you sure it has to be fully automated? Why not have the judge/secretary just pressing a button to record?

That is probably the safest solution, pressing the button at the jump off the board, using a 1sec delayed buffer and 2sec automated recording. The clip has to be short to save the problem of scrolling through the footage.
The clip is immediately played in slo-mo at a second screen for both the judge and athlete to see, by sending it by the reply folder observer. If needed, it will be saved by the competitors number and jump.

It is a question of possible errors - missing the manual start or automated recording (not starting or recording at the wrong instance)...the sound activation was just too sensitive.

What resolution and FPS do you find necessary for this?


I don't use any automation. The judge starts and ends the recording.
I used a 30fps camera but now I've bought a new 60fps to try to get better detail. The 30fps camera will be installed pointed at the athlete bib so we can be sure that that image is from that athlete.


If motion detection is needed, the software ZoneTrigger can be used to activate dedicated HotKeys to start the Kinovea recording. You will need two cameras; one for the trigger and an other for Kinovea....


OK. This is probably my "final" solution:

I have a Xiaomi Redmi Pro 10 android smartphone (FHD at 60fps or high speed 120fps) filming the board, connected by USB to my PC. The camera can be started/stopped with a bluetooth remote button I bought from ClaesOhlsson. The smartphone is seen as a external disk and I can manually drag every, new file to a replay folder on my screen. I have two Kinoveas running observing the replay folder; one is playing the clip on a separate screen and the second is for closer analysis/zoom/step by step/saving if needed.
The process from the jump to showing&analyzing the clip takes 10-15 seconds....


For this application I think it's paramount that the board be vertically aligned perfectly with the edges of the image, pixel wise. Otherwise if it's not filmed straight down it could be misleading and impossible to really say whether the shoe actually crossed the board before take off or not. I want to add more options to the "Camera test grid" object for this kind of scenarios. Maybe a simple vertical line for starters.


Yes, Joan, definitely and there is an optimal height, too.....if the camera is placed too low, the perspective of the board and focus can be distorted....if it is too high, there is a risk of the swinging foot covering a critical frame at the board.


Maybe with a large mirror on the opposite side of the camera, this way if the free leg is blocking the view you may still have a clear shot visible in the mirror. To avoid having a second camera looking from the other side.


There are a number of people in the UK who are looking at and/or using Kinovea with various cameras for judging LJ/TJ take off. We hope to have some guidance from the Technical Advisory Group (TAG) regarding this setup. I recently delivered a workshop to a group of Technical Officials at the Southern Officials Conference showing how the system can be used, at present I have £88 camera from Amazon that allows me to capture 720p images at 120fps which we hope will be good enough. The onething I have been asked over and over again is about a single button capture start, rather than having to position the mouse over the Record  button then click it. Are there any plans for this to be available or being able to create a HotKey for this. The second option would be really good as we could then attach and external button and programme this to the same hotkey.

I know this has been used at a Northern Athletics Open meeting recently and will be used at Southern Athletics Indoor meetings as well as at Loughborough University Indoor Opens.