DVXplorer strange noise issue

[kazuto ichimaru]

Dear all,

I'm trying to reproduce this paper's method using DVXplorer and Sony MP-CD1 laser projector.
https://arxiv.org/pdf/2111.15510
As mentioned in the paper, it seems the event timestamps almost follow projector's scanline (60fps).

However, when I visualized event timestamps with a grayscale heatmap (brighter means newer) for 16.67ms time window,
I noticed strange grid-like noise pattern exists only on the left half (please see the attached image).
First, I thought this is due to lossy read-out mode (CONSTANT_LOSSY_5000), but it happens with any eFPS mode.
I would be very happy if you kindly introduce me some possible causes and solutions.

Of course, the projected image is just a white image, and has no grid-like pattern.
Similar issue also happens with a DLP projector.

Thank you for your support.

[Luca Longinotti]

Hello. The only settings that can influence readout are eFPS, Global Hold and Global Reset.

If you've already ruled out eFPS settings, I'd recommend trying to change Global Hold.

-- 

Luca Longinotti (llongi)

Senior Software Engineer
iniVation AG - https://inivation.com/
A SynSense Group company

[kazuto ichimaru]

Thank you for the information.

Unfortunately, changing Global hold and Global reset did not improve the event quality.

As a new thing I noticed, the noise pattern is different by time, which means this appears to be a natural phenomenon rather than a mechanical factor.

Should I suspect some external factors such as over exposure?

Thanks,

2025年2月23日日曜日 3:04:33 UTC+9 Luca Longinotti:

[Luca Longinotti]

Is the pattern really repeatable? What if you flip the camera 180°, does it then change to be on the right side?

Did you try one of the slow, constant eFPS settings like CONSTANT_100 ?

Have you tried with any other computers, maybe more powerful desktops? (In case the current one gets overwhelmed often and drops data often)