How to preview "processed​/field-cor​rected" camera feed live / efficiently?

Any suggestion how to preview a camera input efficiently after processing the camera data? The "preview function" currently only works witht the following. If one has to correct the camera feed before displaying, can we still use preview function? or better alternative?

says, I would like to correct video stream on the fly like the following:

stream=getsnapshot(app.CamVid); and display this "stream./[matrix of calibration]" live!

[Eric Ng]

My current approach is using self-define-computePlot function, which is still slightly slower than preview function which is directly showing the video live. Any better suggestion?

hImage = imagesc(app.UIAxes, getsnapshot(app.CamVid));

set(app.CamVid, 'TimerFcn', {@SelfDefine-computePlotFunc, hImage}, 'TimerPeriod', 0.2,'FramesPerTrigger',Inf);

start(app.CamVid);