1 Topic by Rogerio

  • Rogerio
  • Member
  • Offline

Hello!
I have a problem using angle measurement. I can´t regulate the angle the way i want. I tryed to move lines of the angle but i couldn´t do. How can i move the angle´s lines the way i want?
I have a suggestion. U could put a stick figure model in the program. And a stick figure trajectory too.

Thanks a lot! I wait a reply!

Prof. Rogério Balthazar
Brasília - DF
Brazil

2 Reply by joan

  • joan
  • joan
  • Admin
  • Offline

Hi,
Regarding the angle tool: use the little circles at each line end to move the lines around.

3 Reply by dan

  • dan
  • Member
  • Offline

Hello,

First of all I would like to congratulate Joan for Kinovea ! Nice and very usefull job !
Now, the trouble : because the image it is deformed I have a problem with angle measurement : instead of 45 degree the result is 51 degree. Why ? [I'll send an image on email]
Thank you,
Best regards,
Dan

4 Reply by joan

  • joan
  • joan
  • Admin
  • Offline

Hi, thanks smile
If I understand correctly, the image deformation makes the angle measured different from what you would expect.
As you guess, the tool doesn't know about image content or deformation. It just measures the visible angle between the points set… Or am I misunderstanding and you think there is a defect in the angle tool?

Compensating for image deformation is a hard problem. You'd have to know the internal parameters of the camera to infer the transformation needed to re-adjust / realign it… Maybe there are software to do that?
I remember seeing some tools with a chessboard pattern detection to compute the deformation, maybe it's a lead.

5 Reply by joan

  • joan
  • joan
  • Admin
  • Offline

@Dan:
Ah, from your initial mail I didn't realise the image was vertically squeezed. I understand better now, it is indeed an image aspect ratio issue.
For some reason, when openning your video, Kinovea cannot guess the right ratio to use.

There is a workaround for this kind of issues in the experimental version.

Go to menu Image > Image Format > Force 16:9.
It should fix the issue for this file and the right angle be measured.
If you are processing a lot of these files and they all have the same behavior, you can make this the default in the preferences, at General > Default Image Format.

6 Reply by dan

  • dan
  • Member
  • Offline

Thank you Joan for your promt answer !
I'll try the experimental version !
Please, tell me how can I modify the size of the text on the forum [it is very small and it is a little hard to read....]

Sincerely yours,
Dan

7 Reply by dan

  • dan
  • Member
  • Offline

Hi,

It works well !
Please , help me with distance measuring ! I can work with line toll but I don't see how can I measure the length of the line !:D

Thank you !

8 Reply by joan

  • joan
  • joan
  • Admin
  • Offline

Hi,
You add a line, and then you right click it, and use the "Seal measure" menu.
(Will be renamed to "Calibrate measure")
Any line can be your calibration segment, measure of other segments are computed from it.
I had written a small paragraph about measuring length here.

9 Reply by dan (edited by dan 2010-02-22 07:35:11)

  • dan
  • Member
  • Offline

Hi Joan,

The measuring length works well. To me, there is a problem with displaying the measurement value when I work with two playback screen - it is too small and I can't see it well !
The same problem with the characters from this forum - I can't see well what I am writing ! Sorry for mistakes !

Have a nice day !
Thank you !