Video frame selection
I'm sure this has an easy answer but if I set a trigger to capture 2 frames how can I independently assign '[vid,1]' and '[vid,2]' as variables? My reason for doing this is to subtract one image from another (and then divide the qualitative noise. 2 to the power of 0.5, Dark current calculations). vid = videoinput('gige', 1, 'Mono16'); src = getselectedsource(vid); vid.FramesPerTrigger = 2; start(vid);
Prashant Kumar answered .
2025-11-20
There are a number of ways to this that are roughly equivalent. By default the GETDATA command returns N frames where N is equal to the value of the FramesPerTrigger property when GETDATA is called. You could do something like:
data = getdata(vid); diffFrame = data(:,:,:,2) - data(:,:,:,1);
You can also specify the number of frames that GETDATA should return:
image1 = getdata(vid, 1); % Here 1 is the number of frames to return image2 = getdata(vid, 1); diffFrame = image2 - image1;
Of course, you could also do:
data = getdata(vid); % Get both frames image1 = data(:,:,:,1); % The first frame image2 = data(:,:,:,2); % The second frame diffFrame = image2 - image1;