SuperPixel Mode 64mp cam

Raspberry Pi Cameras
1
  1. Where did you get the camera module(s)?
    uctronic
  2. Model number of the product(s)?

  1. What hardware/platform were you working on?
    rpi

  2. Instructions you have followed. (link/manual/etc.)

  3. Problems you were having?
    camera in low light conditions not as good as imx519

  4. The dmesg log from your hardware?

  1. Troubleshooting attempts you’ve made?
    Tried to use camera in superpixel mode (4624x3472).
  2. What help do you need?
    Would expect at low light conditions looking at the bigger sensor of 1/1.7" a brighter picture, but I do not.
    Is the principle of superpixel not, to double the amount of light received by each image pixel by reducing the resolution to 16mp? I do not need 64mp but would like to profit from the bigger sensor the 64mp cam has compared to the imx519.
    Having both cameras pointing to the same spot at same time, the imx519 (both cams at 16mp) outperforms the 64mp’s image quality in lowlight conditions.

Any tips?

2

If you take a 64 mp image and process it to a 16 mp you are down sampling, meaning you average 4 pixels from the original image into one pixel for the new lower resolution image resulting in a cleaner image with less noise. If this is the process the software is using then you should have a cleaner, near same brightness image.
Try to compare the 16mp merged image to the basic imx519 image in terms of noise. If the process is not merging and just taking one pixel out of 4 then the 64mp to 16 mp image and the basic image imx image would be comparable. hope I’m not mistaken

3

At first sight this seems logic to me.
I would expect that from 64mp cam in 16mp mode 4 pixel make up one pixel in image file (averaged).
On the other hand, the sensor of the 64mp cam is 1/1.7" compared to 1/2.53" of imx519. I do not see really a positive impact of the bigger sensor on the final image both at 16mp.

4

Here is a comparison.
Left side imx519, right arducam 64mp.

The 64mp cam is limited to 6.0 gain, imx519 is capped at 8.0. Why is that?

grafik
grafik1920×208 35.2 KB

5

And please compare the image at same shutter and same gain:

grafik
grafik1920×480 58.7 KB

Either I am missing something or the bigger sensor has actually no benefit…

1 Like
6

Any reply from Arducam on this?

1 Like
7

Hi,
Different sensors have different hardware parameters. It makes no sense to compare these two cameras this way. You can use manual exposure.

8

It is very difficult to get a 64Mpix photo in native resolution from the camera. Even if you use --mode 9152:6944 --width 9152 --height 6944 in libcamera-still, the library will still only return the photo enlarged to 64Mpix from 16Mpix. That’s why you can’t see much difference.

The difference was only when I used picamera2 to get the native 64Mpix resolution from the camera with Sharpness = 2

#!/usr/bin/python3
import time

from picamera2 import Picamera2
from datetime import datetime

manual_focus = 428.0

picam2 = Picamera2()
picam2.set_logging(Picamera2.DEBUG)
picam2.options['quality'] =95  # values from 0 to 100
capture_config = picam2.create_still_configuration()

picam2.configure(capture_config)
#picam2.set_controls({"AfMode": 1 ,"AfTrigger": 0})
picam2.set_controls({"AfMode": 0, "LensPosition": manual_focus, "AnalogueGain": 1.0, "AwbMode": 5, "Sharpness":2})
picam2.start()

#for autofocus
#time.sleep(35) 

#picam2.capture_file("demo1.jpg")
#picam2.stop()

file_name = datetime.now().strftime("%y_%m_%d-%-H-%M-%S")

request = picam2.capture_request()
request.save("main", "/home/pi/Desktop/Images/"+ file_name +".jpg")