Get a capture from CMOS Camera

[lungoci_a]

Hi all !

I want to get a capture from CMOS camera. I tried using V4l but ioctl
function drop an error. Also I tried with OpenCV and I have the same error.

I tried with usb webcam but after plug in I can't find /dev/vide0.

Why my kernel 2.6.29 doesn't have /dev/video0 ?

How can I get a capture from CMOS camera or using USB Webcam ?

Many Thanks !

[philp]

Hi

the CD that comes with the Mini2440 has an 'examples' directory with various very useful code examples. Look for 'camtest' and the file 'camtest.cpp'.

I used this as a template and was able to get up and running quite easily.

Note that the CMOS camera is not a V4L device, but has a driver ( s3c2440camera.ko) uses '/dev/camera'

I have also been tweaking the driver itself for our own needs - not too hard, although the SMOS camera datasheet is a tad cryptic.

cheers
phil

[lungoci_a]

Hi philp.

thanks for your response. I know that the CMOS camera have a /dev/camera. This is my problem.

I want to use the camera for real time image
processing (interfacing with OpenCV or V4L). After a long time on google
search I decide to implement this using one of two methods:

1. To get a frame from CMOS camera in RGB565 format ( exactly like you said
) and convert it into OpenCV buffer ( "Ipl format" ). And here I need the
help. It's this possible ?

2. To buy a USB camera (UVC device) and try to interfacing it with OpenCV.
Can I use V4L or OpenCV in this case ? Which USB camera ?

3. I can use your modified driver but can I interfacing it with V4L or
OpenCV ?

Which method you think it is fastest ?

Any other method you have I'm ready to try it.

Thanks for everything.

[philp]

> I want to use the camera for real time image
> processing (interfacing with OpenCV or V4L).

we do real time stuff, but do not care about V4L or OpenCV. We have used V4L stuff on other platforms, but don't have any reason to do so on the Min2440

>1. To get a frame from CMOS camera in RGB565 format ( exactly like you said
> ) and convert it into OpenCV buffer ( "Ipl format" ). And here I need the
> help. It's this possible ?

don't see why it would be difficult, but not using OpenCV I can't help. Try the example cam program and get an image to get started, then consider the result.

> 2. To buy a USB camera (UVC device) and try to interfacing it with OpenCV.
> Can I use V4L or OpenCV in this case ? Which USB camera ?

I bought a couple of cheap Logitech cameras over christmas and tried them - they operate OK, but we don't do any image processing withthem yet. They use the 'Gspca/Spca5xx' driber stiff - lots of people use that stuff, so should be easy to find webcams and code for them - a goog;e for 'linux webcam gspca' will provide many answers.

> 3. I can use your modified driver but can I interfacing it with V4L or
> OpenCV ?

the driver tweaking is for our purposes - very unlikley to be of use to others.

> Which method you think it is fastest ?

I suggest you use the example app and just start getting images - thats what i did and it was easy to get going



phil

[neyna]

Hi philp,

I bought a couple of cheap Logitech cameras over christmas and tried them - they operate OK, but we don't do any image processing withthem yet. They use the 'Gspca/Spca5xx' driber stiff - lots of people use that stuff, so should be easy to find webcams and code for them - a goog;e for 'linux webcam gspca' will provide many answers.

I bought a logitech C200. It's a UVC webcam which operate at max 176x144 (mini2440 is USB1.1 and not USB2).
Which camera are you using with mini2440 and at which resolution? (I need a better than 176x144).

Thanks in advance,