Which frame is taken as a reference for "Patch Motion Correction"?

Hi cryosparc developers

Would you please let me know which frame is taken as a reference during motion correction in cryosparc? In other words, which frame has zero adjustment and the other frames are adjusted accordingly?

Thank you.

Alpay

Hi @alburse, is this in the context of using the motion trajectory outputs from patch-motion?

The first used frame (so typically frame zero, unless you opted to ignore leading frames) is the reference, in a sense - but if you are trying to shift frames to match up so that averaging them would yield the same output as patch motion, then if I’m not mistaken you don’t need to worry about a reference frame. Each frame should just be shifted by the amount that the trajectory output indicates, and this will result in the correct output. None of the frames necessarily have zero shift.