Raspberry Pi Forums

Good Day

Toda y was muy first Day using Raspberry 3 and the raspberry camera (8MP). I have a project that I will used the camera with 720 x 720 resolution, and that was easy, but I didn't find information on how can I do to make the video on circle shape... I need the video in a circle or 720p of diameter, all the other will be ignored (black pixels), this is because where the camera will be installed it only see this shape (will be inside a tube) and I want this because maybe ignoring all the pixels that I doesn't need the process will be faster.... Some idea on how to kill all the pixels that I don't need? On how can I get a video in circle shape?

I would suggest in your software to only process the pixel area (region of interest) needed regardless what is coming from the camera

Simplest option - put a mask over the screen that has a circular cutout in it.You only see the circular image. If you have a tube anyway doesn't that mask out the corners?

You could create a mask graphic as a DispmanX layer above the camera preview.
You could look at picamera.http://picamera.overlay.renderer:
readthedocs.io/en/release-1.10/api_renderers.html?highlight=overlay.renderer

You could paint the camera image a line at a time in a circle but that will most likely be slower than letting the GPU update the square.

Alternatively you could just snip off the corners with a sharp pair of scissors. [JOKE]

I think you need to look at the region of interest flag. --roi in raspistill. See the docs.

jamesh wrote: ↑

Tue Sep 12, 2017 8:37 am

I think you need to look at the region of interest flag. --roi in raspistill. See the docs.

That doesn't help with circular area of interest, does it?
It seems -roi is already used:

RobertoRD wrote: I will used the camera with 720 x 720 resolution, and that was easy, but I didn't find information on how can I do to make the video on circle shape...

PiGraham wrote: ↑

Thu Sep 14, 2017 9:16 am

jamesh wrote: ↑

Tue Sep 12, 2017 8:37 am

I think you need to look at the region of interest flag. --roi in raspistill. See the docs.

That doesn't help with circular area of interest, does it?
It seems -roi is already used:

RobertoRD wrote: I will used the camera with 720 x 720 resolution, and that was easy, but I didn't find information on how can I do to make the video on circle shape...

I think the OP is simply using the x and y resolution at 720x720, so the output from the sensor is that (or near). Then he will need to use the -roi flag to clip that down to the area around the circle. If he is pointing down a tube, he already has the circular mask.

Thanks all for yours comments, sorry for the date that i'm responding, the program need to be on python. Can some one can give me an example of the -roi? I a newbie using raspberry, linux and python