Global Shutter Camera Module with higher fps for small ROI

Discussion related to "under the hood" OpenMV topics.
pino
Posts: 2
Joined: Thu Nov 21, 2019 1:15 am

Global Shutter Camera Module with higher fps for small ROI

Postby pino » Thu Nov 21, 2019 1:58 am

Hi,

I'm playing with the Global Shutter Camera Module + OpenMV Cam H7. I'd like to have a higher fps, more than 200 fps, with maintaining the spatial resolution. I tried the example code in github: openmv/scripts/examples/28-Global-Shutter/high_fps.py with sensor.VGA, sensor.QVGA, and sensor.QQVGA options. I was able to get a high fps with QQQVGA but the spatial resolution is degraded. The fields of view are the same between VGA and QQVGA. So, I guess that the QQVGA mode is realized by pixel binning. However, I'd like to avoid the pixel binning, since this results in the spatial resolution reduction. I'd prefer to do windowing or setting ROI. So, I tested the windowing by using the function sensor.set_windowing() with VGA framesize. However, the frame rate is low, the same fps as the VGA without windowing.

Is there a way to achieve higher fps with original spatial resolution? Any suggestions?
User avatar
kwagyeman
Posts: 3832
Joined: Sun May 24, 2015 2:10 pm

Re: Global Shutter Camera Module with higher fps for small ROI

Postby kwagyeman » Thu Nov 21, 2019 12:33 pm

Hi, yes, but our driver doesn't support it. You have to manually do register writes to the camera for this. You can do this all through the Python API but you need to read the sensor data sheet to achieve what you want.

Please go the product page and see the sensor data sheet. Then find the mt9v034.c file in our code repo. Under the set frame size method you can see how we set the image read out size and turn pixel binning on as you lower the resolution.

So, you just need to run the set frame size code that you'd execute like normal and then after do a series of register writes to move the ROI of the camera readout to what you want to look at. This will give you a very high fps without any binning.

If you get this working please share the code and we my and an example to the IDE for this.
Nyamekye,
pino
Posts: 2
Joined: Thu Nov 21, 2019 1:15 am

Re: Global Shutter Camera Module with higher fps for small ROI

Postby pino » Fri Nov 22, 2019 6:18 pm

Thank you very much. I'll try it!

Return to “Technical Discussion”

Who is online

Users browsing this forum: No registered users and 6 guests