To acquire images from a webcam from MATLAB 7.9 (R2009b) I just needed to:

imaqhwinfo
ans =

InstalledAdaptors: {'coreco' 'winvideo'}
MATLABVersion: '7.9 (R2009b)'
ToolboxName: 'Image Acquisition Toolbox'
ToolboxVersion: '3.4 (R2009b)'

Tells us what video adapters we have.

wininfo= imaqhwinfo('winvideo')
wininfo =

AdaptorDllName: [1x87 char]
AdaptorDllVersion: '3.4 (R2009b)'
AdaptorName: 'winvideo'
DeviceIDs: {[1]}
DeviceInfo: [1x1 struct]

With this we find the DeviceID (1) of the webcam.
Now, if we go wininfo struct, from there to DeviceInfo struct there we will find an array called SupportedFormats of our webcam.

I’ll use ‘YUY2_320x240′:

winvid = videoinput('winvideo',1,'YUY2_320x240');

In my case the imagenes are being returned in YUV for default, to change this you need to change the ReturnedColorSpace variable from the object winvid (I do this from the variables explorer of MATLAB like in the screenshot above). I changed it to RGB.

preview(winvid);

With this we can see the webcam :) Example of whats the window like:

With:

capt1 = getsnapshot(winvid);

We capture an image.

We can show it using:

imshow(capt1);

For example.

For learning more stuff we can go to the MATLAB help and search for Image Acquisition Toolbox and search what we need.

Source: madan.wordpress.com

Tags: 7.9, acquire data, acquiring, imagenes, images, matlab, toolbox, webcam