AR1820 18MP bad picture quality
Published by fshero on
- October 24, 2019 at 1:55 pm #11722
For one of our projects we are currently trying to get a Arducam AR1820 with 18MP running with a Raspberry Pi. We connected the camera successfully to the Raspberry Pi and getting pictures out of it. Our current problem is, that the pictures that we took until now look terrible. They look grainy and over saturated.
We already tried out many settings, but nothing seems to help very well.
We think the sensor has much more potential, but the API/SDK is not getting all out of it. It seems there aren’t used all 12 Bits per Pixel that the sensor is capable of.
Does anybody get good pictures out of this sensor?
- October 25, 2019 at 8:43 am #11731
The AR1820 18MP camera is RAW camera, which doesn’t have lens shading correction, auto exposure and auto white balance processing on the camera board. So bascially it is better to capture raw image and do image processing on Raspberry pi afterwards. We also have software auto exposure and auto white balance implementation in the SDK/API, you can enable it in the demo code for testing. And we are improve the image quality on our camera driver right now especially the lens shading, we will update the driver very soon.
We are open for further disucssion if you can provide more detail requirement on your end.
- November 6, 2019 at 3:30 pm #12025
Thank you for your reply 🙂
I already tried out your auto exposure and white balance processing but this doesn’t work very well for me. The picures are oversaturate, to brigth and grainy. I think this couldn also be removed with raw postprocessing
Maybe it has something to do with the lense used. It is a 200° (maybe even more) fisheye lense, that produces many black parts around the corners to get circular picture. Maybe your software auto white balance tries to compensate this black parts and increases the exposure. So it gets to brigtht.
I uploaded a sample pic that I took with manual settings (exposure: 425, gain:14)
(btw: how do i calculate the real exposure time out of the exposure value)
I also update the latest drivers, but that doesent really help… 🙁
Do you have any further recommendations, what I can try next?
- November 13, 2019 at 6:59 am #12560
At present, we are optimizing the quality of the mipi camera. Due to we don’t have the hardware ISP support, which means it’s not easy to adjust auto white balance and auto exposure. But you can use arducam_set_control(camera_instance, V4L2_CID_EXPOSURE, value) to adjust the exposure time manually. Use the arducam_manual_set_awb_compensation(r_gain_conpensation,b_gain_conpensation); to adjust the R_gain and B_gain to adjust the white balance.
We are finding a better solution to solve the quality of image.
- November 13, 2019 at 7:54 am #12584
You are right, using the fisheye lens there will be dark corner and make the auto exposure and auto white balance don’t work very well.
Now you can disable the software auto exposure and white balance, manually set the exposure time and gain settings through direct register access (you can find the examples from register I2C read write).