Any object scanning using camera and capture image without and sound or user iteraction

Using camera i just want to scan a image and and every second capture image without user knowing. I want to create a image scanner which will take image. For this i have used image-preview plugin. its working but on the time of capturing its is giving capture sound and also on the time capture camera getting stand for fraction of second. how do i make a image scanner and that image after every interval i can see.