I have a Logitech webcam (QuickCam Pro for Notebooks), and I'd like to take a snapshot using the cam from a command line.
Does it have any command line interface?
If not, is there an API that will allow me to build a command line tool like this?
You could use OpenCV to build such a command line application yourself. Basically you would use captureFromCam() to initialize the camera and then call QueryFrame() to capture a picture. Should be straightforward.
I know this is an old discussion, but maybe you arrived here like I did recently looking for a simple command line app to capture a snapshot image from a webcam in Windows. If so, have a look at the following post on my blog:
http://batchloaf.wordpress.com/2011/04/06/snapz-a-command-line-cam-image-grabber/
It's about a little program called snapz that I've just written to take a snapshot from a USB camera in a batch file. It's really basic - when you run it, it snaps a 640x480 image from the default video capture device (e.g. webcam) and saves it to the current directory. It's free and easy to use.
The question itself is not programming related, just a request of some hardwares bundled softwares documentation.
I will answer the question as it WAS a programming question.
If you talking about webcams on a windows OS you can use DirectShow as in this example:
http://www.codeproject.com/KB/audio-video/WebcamUsingDirectShowNET.aspx
Just create a console application in visual studio that takes some commandline parameters and let it use the code in the example and you are on your way.
来源：https://stackoverflow.com/questions/1516191/take-picture-using-webcam-from-command-line