Hi Douglas,

I've used Tracker software for my PhD project, and this is brilliant.

I'd like to ask what the difference between 'Point mass' and RGB region is because I got different x and y coordinates when I used both functions. Everything was the same in terms of a video I chose, the location of a target and length of frames. Briefly, I've analysed ultrasound videos, so all gray scale images and the key frame always includes clear white curved shapes.  

What I understood was regardless of the function I choose, 'autotracking' tracks images using its mechanism (RGB difference). Therefore, x and y values would be same when I use Point Mass or RGB Region.

Also, 'Tape Measure' function is crucial for me, but I realized I can't attach to a crossline when I used RGB Region. I was wondering if you plan to include this in the next update.

Thanks,
Joon