Starvis2 HDR?

[Nigel]

I am not sure if the information in this video is correct, but it definitely piqued my interest in what the author says about "Clear HDR"
This is somewhat contradictory to your explanation. Where is the truth?

Viofo actually develops dashcams, so he knows the truth much better than the author of that video; good video but includes some speculation.

I also suspect his monitors need some adjustment based on his comments about image quality 🤔

On the HDR performance, I suspect he had the N4 mounted in the best position. The HDR needs to see light from your headlights being reflected in the plates for it to work properly, so the best place to mount it is directly behind the headlights; going offline and higher can make a fair difference to the performance.

He is correct about the A139 Pro having better performance in single channel mode than 3 channel, single channel 60Mbps is very nice quality.

 

[Superturisto]

On the HDR performance, I suspect he had the N4 mounted in the best position. The HDR needs to see light from your headlights being reflected in the plates for it to work properly, so the best place to mount it is directly behind the headlights; going offline and higher can make a fair difference to the performance.

It makes no sense. What you are saying is that the quality of the image will depend on the height of the reflective object? Correct me if I am wrong.
You are also saying that 'Viofo actually develops dashcams,' however, it doesn't mean that they implemented all the features of the Starvis 2 chip and did it in the best possible way.
SONY Starvis 2 Overview

 

[Dashmellow]

The Starvis 2 is actually a large family of sensors used in a wide range of cameras. There are many features and potential implementations according to the needs of the particular product.

 

[Nigel]

What you are saying is that the quality of the image will depend on the height of the reflective object? Correct me if I am wrong.

No, number plates, in most parts of the world, are retro-reflective, so the light from your headlamps bounces back to the source. The height of the plate reflecting the light does not matter, but the height of the dashcam relative to the height of your headlights does. Look up retro-reflective if you don't know what it means.

You are also saying that 'Viofo actually develops dashcams,' however, it doesn't mean that they implemented all the features of the Starvis 2 chip and did it in the best possible way.

That is true, and actually correct, but I was only pointing out that Viofo understands how his cameras work much better than the person in the video, who was only speculating on how the HDR had been implemented in the various dashcams, and does make it clear in the video that he doesn't know for certain, while Viofo does know which form of HDR his cameras use, and why that form was chosen. Personally, I can not see how Clear HDR could work any better for our application than what Viofo use now.

 

[viofo]

It makes no sense. What you are saying is that the quality of the image will depend on the height of the reflective object? Correct me if I am wrong.
You are also saying that 'Viofo actually develops dashcams,' however, it doesn't mean that they implemented all the features of the Starvis 2 chip and did it in the best possible way.
SONY Starvis 2 Overview

Normally we have one step forward than most Chinese dash cam for IQ tuning. That's why we released the IMX678 & IMX675 dashcam first in the market.

VIOFO spent lots of time tuning the clear HDR on A139 Pro which uses the Novatek NT98687 chipset. We know the disadvantages of the CLEAR HDR.

As I know, Novatek removed the CLEAR HDR support on the NT98529 platform, I don't think there is any other manufacturer that even tried CLEAR HDR on their dashcam.

 

[Cyker]

Aww that's a shame, Sony's marketting blurb for clearhdr suggested it would be useful with fast movement which is what got me excited for it in the first place, so it sucks that that's not the case 🙁

BTW, I forget if I asked already, but is there any chance you could implement AutoHDR based on light levels rather than just time? It would just save me having to change the times for winter and summer...

 

[Dashmellow]

Aww that's a shame, Sony's marketting blurb for clearhdr suggested it would be useful with fast movement which is what got me excited for it in the first place, so it sucks that that's not the case 🙁

So far that seems to be mostly on CCTV cameras probably because this type of camera is usually mounted in a static position on buildings and poles rather that on moving vehicles which tends to make motion blur capture even more challenging.

Maybe the technology will migrate at some point to the versions of the sensor used in dash cams?

 

[Nigel]

Aww that's a shame, Sony's marketting blurb for clearhdr suggested it would be useful with fast movement which is what got me excited for it in the first place, so it sucks that that's not the case 🙁

If you were making a movie, where you want some motion blur, then it would be ideal for fast motion. However we want to eliminate motion blur rather than enhance it!

BTW, I forget if I asked already, but is there any chance you could implement AutoHDR based on light levels rather than just time? It would just save me having to change the times for winter and summer...

Yes, it would then turn on while driving through tunnels.

 

[Cyker]

If you were making a movie, where you want some motion blur, then it would be ideal for fast motion. However we want to eliminate motion blur rather than enhance it!

I think there's some confusion here - The whole point of ClearHDR was to remove the 2-frame blur caused by regular HDR taking 2 frames at slightly different times - It would have reduced blur effects, not increased them.

As it stands, the reason everyone says to not use HDR during the day is because it yields the least blurry single-frame images because it just takes a single frame at a single instant, and not 2 at different times that are overlaid.

Yes, it would then turn on while driving through tunnels.

Yes! Or when there is unexpected cloud cover, or driving through a forest - Anywhere where it's dark enough the HDR becomes beneficial.

 

[Nigel]

I think there's some confusion here - The whole point of ClearHDR was to remove the 2-frame blur caused by regular HDR taking 2 frames at slightly different times - It would have reduced blur effects, not increased them.

I think the confusion is Sony's fault!

With Clear HDR you only see 1 exposure with a high dynamic range - a nice clear image with no processing artefacts, you do not see the ghosting from multiple exposures that you got with previous HDRs, and you do not see what we see from our current DOL-HDR which is a nice sharp numberplate (hopefully) with a motion blurred trail behind it. Instead you just see 1 motion blurred exposure without artefacts. That is for night time, in day light the Clear HDR will not be motion blurred, but then neither is the DOL-HDR.

Yes! Or when there is unexpected cloud cover, or driving through a forest - Anywhere where it's dark enough the HDR becomes beneficial.

And when does the HDR become beneficial?

Only when you have your headlights on?

 

[viofo]

The DOL HDR benefits the short exposure to capture license plate numbers.
But for the CLEAR HDR, it uses the same exposure time for two frames, so it doesn't help to get a clearer license plate number, and very high noise for night recording.