I am trying to calibrate marker trajectory coordinates from px to cm. I used "line" to draw a "vertical" line and calibrated because I only needed vertical coordinates. It seems that this switches xs and ys when I look at the data in Excel. This didn't happen with previous versions.
1 2021-02-10 23:44:09 (edited by yhs5253 2021-02-10 23:44:48)
- joan
- Admin
- Offline
Yes. This should be fixed in the next version.
Allow me to clarify what is happening. In previous versions the direction of the calibration line was completely ignored, and the coordinate system was always aligned with the image axes. This was a bit restrictive, if the camera was rotated a bit you couldn't really get vertical or horizontal coordinates in world space, they were always aligned with the rotated camera. We had to use the plane calibration to work around this limitation.
In 0.9.3 the line direction is used as the horizontal axis. This way we can have a rotated camera and still get coherent coordinates. But as you noted this is not always desirable.
In the next version when you define the scale of the line you also tell if this line is along the horizontal axis, the vertical axis, or if its direction should be ignored and the coordinate system should use the image axes.
3 2021-02-11 17:21:14 (edited by yhs5253 2021-02-11 17:22:53)
Thank you for your quick response.
It sounds like the next version will be very nice!