Motion - Bug Report 2004x 11x 13x 202132

BUG: pwc motion tracking problem

My quickcam orbit didn't correctly move the camera towards a moving object.

This seems to be caused by the fact that the y-axis is inverted. The camera Y axis maps from 2500 at the top to -3500 at the bottom, while the image Y axis is from 0 at the top to img.height at the bottom. So a positive delta_y on the image should be mapped to a negative delta_y on the camera.

The attached patch is against 3.1.14, but I checked the changelogs and the 3.1.18snap6 source and it looks like the problem is still there.

Test case

'motion-control track auto 0 1' with a logitech quickcam orbit. Move your hand at the bottom and the camera will move up. Create motion at the top and the camera moves down. Apply the patch and the camera will move (somewhat) towards the moving object. It isn't really tracking the way I expected it to since it seems to reset/disable the motion detection for 10 frames after tracking, so I guess it depends on the fps at which we're capturing and the 2 second delay at 5 fps makes the tracking pretty unpredictable.


Motion version: All versions
Shared libraries: curl, xmlrpc, ffmpeg, mysql
Server OS: Debian-unstable

-- TWikiGuest - 13 Nov 2004

Follow up

Great finding. Now my Sphere finally stopped starring at the sky.

You are right that the timing needs to get more intelligent.

But at least the camera follows in the right direction now.

Patch is already added to my sources and will be in Motion 3.1.18

Fix record

Fix released in MotionRelease3x1x18snap7
Topic revision: r3 - 20 Dec 2004, KennethLavrsen
Copyright © 1999-2024 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Please do not email Kenneth for support questions (read why). Use the Support Requests page or join the Mailing List.
This website only use harmless session cookies. See Cookie Policy for details. By using this website you accept the use of these cookies.