Taking a panorama - I get an upward bias until the rectangle disappears off the top

[Tim Cooper4]

This problem occurs with a Galaxy S7 and a Galaxy S8 and probably all Android phones that use the built-in camera app. It involves the built-in camera app, and its "panorama mode" and 360 degree panoramas which are supposed to wrap around/join up.

When I try taking a panorama, turning to the right, the little white rectangle slowly but steadily moves upwards. After a certain threshold it turns yellow, and then starts telling me to tilt the phone down, but I'm keeping the tilt steady. The bias gets worse and worse and before I complete my 360 degree panorama, this yellow rectangle has moved so far up and out of range that the app aborts the panorama.

It seems to be worse when there's movement, i.e. crowded places. It happens in both portrait and landscape mode, possibly more in portrait mode. I don't expect good quality pictures in this scenario, I really only need low quality panoramas, but often I just don't get anything at all unless I repeat it time and again.

So presumably there's a bug in the stitching algorithm that gives it an upward bias. If there was no bias, then noisy scenes with lots of movement would give me a "random walk", and that would be fine - I wouldn't lose too many vertical pixels. But with this upward bias, I normally fail to get any panorama at all.

Is there anything I can do to fix this?

 

[Tim Cooper4]

I solved the problem by ignoring the little message "Move down!", and instead paying attention to "roll" - twisting the phone a few degrees clockwise or anticlockwise. Different roll orientations give you a downward bias or an upward bias. I thought I was holding it exactly vertical but either I wasn't, (or I need to have it slightly off vertical to counteract some algorithmic bias).

I would prefer that the built-in software auto-corrects this effect but maybe that's too difficult.