I want to be able to take a picture using the webcam from the terminal. This image then will be saved to a file. How can this be done?
4 Answers
There is another application which can be used to capture the images from the webcam named as Fswebcam. you can install that with
sudo apt-get install fswebcam
you can have a sample shot with the following command.
fswebcam -r 640x480 --jpeg 85 -D 1 web-cam-shot.jpg
In the above code syntax , -r
stands for Image resolution , --jpeg
stand for format type of the image & 85
for its quality standard, -D
stands for delay set before capture.
Now your image finally saved with web-cam-shot.jpg name.
Hope that helps.
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14In my case, my test machine, I had to skip frames to get the picture right. If I take the first frames the picture are very dark, because the camera wasn't ready yet.
fswebcam -r 640x480 --jpeg 100 -D 3 -S 13 fswebcam.jpg
– msmafraFeb 8, 2014 at 14:52 -
1@tenshimsm I spent 10 mins figuring out what was wrong with my fswebcam and then removed the package. Installed it again just to try your approach, 30 frames worked for me. Thanks :) Jul 22, 2014 at 18:50
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what I've wound helpful is: v4lctl bright 50% # apt-get install xawtv Feb 9, 2017 at 0:31
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4
If you're looking for something automated webcam
is pretty decent. It has lots of lovely options for pushing the photos over the Internet.
If you want something more manual, and we're talking about a camera supported by V4L/UVC (most of them) you can use streamer
to capture a frame from the device:
streamer -f jpeg -o image.jpeg
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Thanks Oli. Did not know a webcam program called WEBCAM (The irony...) existed. And yes the webcam is in the V4L supported list. Feb 23, 2012 at 0:46
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If you get something like "
neither audio nor video format specified/found
" with the commandstreamer -f jpeg -o image.jpeg
, try juststreamer -o image.jpeg
. Dec 24, 2019 at 15:36
Using avconv
or ffmpeg
, you can capture a frame from your device as well. For example:
avconv -f video4linux2 -s 640x480 -i /dev/video0 -ss 0:0:2 -frames 1 /tmp/out.jpg
or
ffmpeg -f video4linux2 -s 640x480 -i /dev/video0 -ss 0:0:2 -frames 1 /tmp/out.jpg
This will open /dev/video0
as a video4linux2
compatible device, set up resolution to 640x480
, stream for 2 seconds (00:00:02
or simply 2
), then capture one
single frame, saving it to /tmp/out.jpg
.
Check if your device is /dev/video0
, as it can be different for you.
The available resolutions depend on your webcam. Mine goes up to 640x480 and I checked it with a tool called qv4l2
, which is used to configure a video4linux2 device.
The -ss
parameter is used to allow the device to start up correctly. Here in my tests, there is a fade-in effect while the camera is being turned on, so, if I just omit -ss 2
, the captured frame will be very dark.
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2I preferred this solution as I'd already installed avconv. Also, the output of avconv also gives hints to the maximum resolution, as the v4l driver shows if it has to fall back onto a lower specification. Sep 20, 2018 at 16:31