Bright sun + shaded license plates = OCR failure

[bluetentacle]

Hi, I just added an EmpireTech ZE4 S3 camera to my Blue Iris/CodeProject AI setup, for the purpose of recording license plates.

The setup works extremely well most of the time, including at night.

However, in the early afternoon, when the sun is still up high but no longer shining on the license plates, Blue Iris/CPAI recognizes the license plates, but the OCR of the license plate numbers doesn't work most of the time.

Here's one example of a failed OCR. As you can see, the license plate is recognized but the number is not read.



As the sun goes down and the overall brightness comes down, the OCR starts working again:



Strangely, when I feed the first picture into the CodeProject AI Explorer and click on Read License Plates, it is able to read the plate number:



Does anyone know of a solution to this problem?

 

[actran]

In BI5 console, hold down Ctrl key while you double-click on a thumbnail on the left for a triggered event.
If you enabled "Save AI analysis .DAT files" in your cam AI screen, a pop up will appear when you do above ^ showing more details about what happened.
Share that screenshot, and your cam AI config screen.

 

[bluetentacle]

 

[actran]

If you look at your screenshot, you can see that you got http code 500 from CP.AI and it spent 11+ seconds so it probably gave up (timeout). Not sure what you are running CP.AI on but your PC may not have sufficient resources when alot of requests are coming in at the same time.

You're currently running CP.AI on CPU. If you can't change your CPU easily, offloading CP.AI from CPU to a supported Nvidia card will help alot. 11 seconds is just too long.

 

[bluetentacle]

I have an i7-6700 with integrated GPU. I thought CPAI was using it, but according to the CPAI web UI, it's in CPU mode. Configuration files indicate that GPU is enabled.

Would the onboard GPU work, so do I need a card?

 

[actran]

As I have heard, CP.AI ALPR can only run on CPU or Nvidia GPU. MikeLud1 mentioned this in another thread.

Your CPU and integrated GPU is a bit old so I don't think it will be performant (enough) . Personally, the CP.AI response times in your screenshot above is way too slow, especially if you have alot of both people and vehicle events.

 

[bluetentacle]

CP.AI ALPR can only run on Nvidia GPU. MikeLud1 mentioned this in another thread.

That's good information. My computer is a Dell Precision T3420. Up until I started using ALPR it's served me well.

I understand that Dell T3420 can only use low profile cards. Which GPU does the forum recommend for this computer?

 

[MikeLud1]

I have an i7-6700 with integrated GPU. I thought CPAI was using it, but according to the CPAI web UI, it's in CPU mode. Configuration files indicate that GPU is enabled.

Would the onboard GPU work, so do I need a card?

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View attachment 188119

Try disabling Object Detection (YOLOv5 6.2) and enable Object Detection (YOLOv5 .NET) this module will use you iGPU. Also use the below AI settings.

 

[actran]

@bluetentacle I have a Dell Optiplex SFF so I need a half height card also. This is the one that worked in my PC case:

https://www.amazon.com/gp/product/B087R7V2Q6/

You also need to check the power requirement for the Nvidia card. Many higher end cards need alot of power such that your PSU will not be enough.

Buy a card with 4GB RAM minimum, 2GB may not be enough if you're using alot of different models.

Lastly, check the generation of the card. Older cards are cheaper but CP.AI and other AI software will eventually increase their minimum CUDA version requirement.

 

[bluetentacle]

@MikeLud1 with your settings, now I'm not wasting any time with Object Detection, instead I'm using the ALPR module only. This certainly improved the response time.



Let's see what happens when the system encounters the full sun/shaded plate scenario again.

Meanwhile, I ordered a single slot 1650 graphics card:

https://a.co/d/8DXBHN7

. This would allow me to use the PCIE x16 slot which is not possible on this computer with double-slot cards.

 

[MikeLud1]

I ordered a single slot 1650 graphics card:

This GPU will help

 

[actran]

@bluetentacle

FYI, awhile ago, when I installed my Nvidia card in my PC, installing Nvidia driver and CUDA was not enough, CP.AI still did not utilize my GPU.

I had to uninstall CP.AI and reinstall again before GPU was utilized. (A suggestion from MIkeLud1)