User`s guide

preview
17-69
14-, or 16-bit data. The Preview window display supports these higher bit-depth cameras.
However, larger bit data is scaled to 8-bit for the purpose of displaying previewed data. If
you need the full resolution of the data, use the getsnapshot or getdata functions.
Custom Update Function
preview creates application-defined data for the image object, himage, assigning it
the name 'UpdatePreviewWindowFcn' and setting its value to an empty array ([]).
You can configure the value of the 'UpdatePreviewWindowFcn' application data
and retrieve its value using the MATLAB setappdata and getappdata functions,
respectively.
The 'UpdatePreviewWindowFcn' will not necessarily be called for every frame that
is acquired. If a new frame is acquired and the 'UpdatePreviewWindowFcn' for
the previous frame has not yet finished executing, no update will be generated for
the new frame. If you need to execute a function for every acquired frame, use the
FramesAcquiredFcn instead.
You can use this function to define custom processing of the previewed image data. When
preview invokes the function handle you specify, it passes three arguments to your
function:
• obj — The video input object being previewed
• event — An event structure containing image frame information. For more
information, see below.
• himage — A handle to the image object that is being updated