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Create several image acquisition objects — This example creates several video input objects for a single webcam image acquisition device, specifying several different video formats. To run this example on your system, use the imaqhwinfo function to get the object constructor for your image acquisition device and substitute that syntax for the following code.

vid = videoinput('winvideo',1);
vid2 = videoinput('winvideo',1,'RGB24_176x144');
vid3 = videoinput('winvideo',1,'YV12_352x288');

Clean up — Always remove image acquisition objects from memory, and the variables that reference them, when you no longer need them.

You can delete image acquisition objects one at a time, using the delete function.

delete(vid)

You can also delete all the video input objects that currently exist in memory in one call to delete by using the imaqfind function. The imaqfind function returns an array of all the video input objects in memory.

imaqfind

   Video Input Object Array:

   Index:   Type:          Name:  
   1        videoinput     RGB555_128x96-winvideo-1
   2        videoinput     RGB24_176x144-winvideo-1
   3        videoinput     YV12_352x288-winvideo-1

Nest a call to the imaqfind function within the delete function to delete all these objects from memory.

delete(imaqfind)

Note that the variables associated with the objects remain in the workspace.

whos
  Name       Size                   Bytes  Class

  vid        1x1                     1120  videoinput object
  vid2       1x1                     1120  videoinput object
  vid3       1x1                     1120  videoinput object
  vids       1x3                     1280  videoinput object

These variables are not valid image acquisition objects.

isvalid(vid)

ans =
    0

To remove these variables from the workspace, use the clear command.