Optimizing camera image settings

[jrmymllr 0]

I have some Hikvision IP cameras and, never being completely satisfied, am still trying to optimize the image settings. It was fine for awhile, but then I tried increasing the WDR because very sunny areas were washed out, and dark areas were too dark. Well then that increased the overall brightness of the image and made things look strange, not to mention the increased noise during the night.

 

In general, how do you set this up? There's so many settings that cause similar effects, for example, the gain, brightness, and WDR all have some effect on overall brightness. Is there a good strategy other than trial and error?

[the toss 0]

If the foreground is in low light & the background is in bright light (like looking from inside a shop at the entry door and having bright light outside) then adjust the BLC (backlight compensation)

[jrmymllr 0]

If the foreground is in low light & the background is in bright light (like looking from inside a shop at the entry door and having bright light outside) then adjust the BLC (backlight compensation)

 

But this doesn't explain the impact of gain, brightness setting, and WDC on overall brightness. And on my camera, I can't use BLC because with WDR enabled, BLC isn't available, and BLC requires to specify a specific region, but since these are outside cameras that doesn't apply.

[SunnyKim 2]

Trial and Error could be the best option. Hoping the following would help.

Gain control is implemented based on Multipliers or Amplifiers. Brightness is done with offset control, using Adders, applicable before Gain control. WDR is based on Histograms showing a distribution of pixel brightness level (0 to 255 range) of a frame of image. WDR re-distribute the histogram in such a way that bright pixels get darkened and dark pixels are brightened. Most of time, dark ones getting brightened. So, they may recommend to turn off WDR or Gain Up when Lighting is not sufficient at night, as it may amplify, in a good chance, the noise levels for the image sensor involved.

[jrmymllr 0]

Trial and Error could be the best option. Hoping the following would help.

Gain control is implemented based on Multipliers or Amplifiers. Brightness is done with offset control, using Adders, applicable before Gain control. WDR is based on Histograms showing a distribution of pixel brightness level (0 to 255 range) of a frame of image. WDR re-distribute the histogram in such a way that bright pixels get darkened and dark pixels are brightened. Most of time, dark ones getting brightened. So, they may recommend to turn off WDR or Gain Up when Lighting is not sufficient at night, as it may amplify, in a good chance, the noise levels for the image sensor involved.

 

So the brightness is performed before gain? I'm trying to understand when to turn up the gain, and when to turn up brightness.

 

Good explanation of WDR from a technical standpoint, that makes sense. I don't know if this is how all cameras work, but on mine, WDR seems to brighten the entire image more than I'd expect.

[SunnyKim 2]

Your understanding is Correct in that quote" then I tried increasing the WDR because very sunny areas were washed out, and dark areas were too dark."

unquote. And I do not know how the algorithm is implemented on their chipset.

 

And I would try as below.

Please note pixel values are to be represented as 0 to 255. If over than 255, it is clipped to 255, "washed out". No way to get returned with original value, if not properly implemented.

Firstly, Gain Down, say 80%, in stead of Gain Up.

Hoping this action can avoid chances of " Washing out", in case Brightness Up and WDR On in the next coming actions.

Secondly, Brighness Offset, say 10%, UP. This makes Dark Pixels shifted to Bright Pixels. And Bright Pixels could be washed out, but could be saved a little bit, due to "Gain Down" action above. It is true that brightness offset control, in generally common implementations, comes before Gain control. But this case we reverse the path.

Thirdly, Play with WDR. WDR smoothens out the peak distributions of Dark Pixels and Bright Pixels. Bright pixels get shifted to slightly dark levels, and Dark Pixels get shifted to slightly brighter levels. They are wrong if they allow "washing out" in WDR.

[jrmymllr 0]

Your understanding is Correct in that quote" then I tried increasing the WDR because very sunny areas were washed out, and dark areas were too dark."

unquote. And I do not know how the algorithm is implemented on their chipset.

 

And I would try as below.

Please note pixel values are to be represented as 0 to 255. If over than 255, it is clipped to 255, "washed out". No way to get returned with original value, if not properly implemented.

Firstly, Gain Down, say 80%, in stead of Gain Up.

Hoping this action can avoid chances of " Washing out", in case Brightness Up and WDR On in the next coming actions.

Secondly, Brighness Offset, say 10%, UP. This makes Dark Pixels shifted to Bright Pixels. And Bright Pixels could be washed out, but could be saved a little bit, due to "Gain Down" action above. It is true that brightness offset control, in generally common implementations, comes before Gain control. But this case we reverse the path.

Thirdly, Play with WDR. WDR smoothens out the peak distributions of Dark Pixels and Bright Pixels. Bright pixels get shifted to slightly dark levels, and Dark Pixels get shifted to slightly brighter levels. They are wrong if they allow "washing out" in WDR.

 

Thanks, very helpful.

[captainvideo 0]

If you are still not happy with your night time images ,

Proper illumination is your best asset !

[jrmymllr 0]

If you are still not happy with your night time images ,

Proper illumination is your best asset !

 

I know, but in this case I don't want to add extra hardware. I mainly wanted to know how to juggle all the settings, and now it's fairly good.

[captainvideo 0]

Glad to hear it's better .

Just a little more info for you or anyone else .

They now make solar powered exterior led lighting with motion detection .

No electrician needed .not sure how long the battery lasts or how bright

They are but when settings don't help enough ,more light will especially

When properly located

[samchadwikz 0]

In my camera settings if I turn on WDR it makes the image noisier is it the problem with hardware or is it just normal?

 

Trial and Error could be the best option. Hoping the following would help.

Gain control is implemented based on Multipliers or Amplifiers. Brightness is done with offset control, using Adders, applicable before Gain control. WDR is based on Histograms showing a distribution of pixel brightness level (0 to 255 range) of a frame of image. WDR re-distribute the histogram in such a way that bright pixels get darkened and dark pixels are brightened. Most of time, dark ones getting brightened. So, they may recommend to turn off WDR or Gain Up when Lighting is not sufficient at night, as it may amplify, in a good chance, the noise levels for the image sensor involved.

[SunnyKim 2]

As explained above, it is not the problem. That's the way it goes. WDR increases, in general, Contrast among neighboring pixels and at the same time, increasing Noise level. So WDR is not to be recommended at night (Low Lighted)

In my camera settings if I turn on WDR it makes the image noisier is it the problem with hardware or is it just normal?

 

Trial and Error could be the best option. Hoping the following would help.

Gain control is implemented based on Multipliers or Amplifiers. Brightness is done with offset control, using Adders, applicable before Gain control. WDR is based on Histograms showing a distribution of pixel brightness level (0 to 255 range) of a frame of image. WDR re-distribute the histogram in such a way that bright pixels get darkened and dark pixels are brightened. Most of time, dark ones getting brightened. So, they may recommend to turn off WDR or Gain Up when Lighting is not sufficient at night, as it may amplify, in a good chance, the noise levels for the image sensor involved.