Preview in MATLAB GUI

Hello, so I am creating a GUI where I want to have a preview of a video, but without it opening up in another window. Is that possible? preview() opens another window, and I tried to experiment with imshow, but I'm not sure on how to really do this. My computer is attached to a camera device and I already have that setup. Thank you!

Answer 1

[Kevin Holly]

Please see Previewing Data in Custom GUIs.

You can use the command:

preview(vid, hImage);

where hImage is the handle to the image object in which the data is to be displayed.

How are you creating your UI? Are you using App Designer?

[Chloe Soriano]

Hello, yes I am using App Designer. I tried using hImage and I was using an axes object as the handle, but I get an error saying, "The specified image handle must be a valid 1XN image object handle, where N represent the specified video input's object's length." I'm not sure on how to check the dimensions of an axes object if that what it was referring to.

[Walter Roberson]

@Chloe Soriano

You do not pass in an axes handle for the second parameter of preview(): you pass in the handle an image() object. For example,

ax = app.UIAxes2;
z = zeros(640,480,3);
hImage = image(z);
preview(vid, hImage);

It turns out to be possible for vid to be a vector of videoinput() results; in that case, hImage would have to be a row vector of image() objects the same length as vid is. This is something that would be used if you were previewing several video input devices simultaneously.

[Chloe Soriano]

I was able to get it to display into the UIAxes; however, it only records a small, "zoomed in" section of the vidoe input and only fits a small part of the UIAxes/doesn't extend to the edges. How to fix this?