Thanks for the reply.
Actual requirement of my project is, I want to develop a document scanning application like camscanner, scanbot sdk (document scanning sdk).
In these applications the camera preview is opened and as the camera detects a document, it places an overlay automatically (bounding box - by detecting the contours ) and then captures only the image that is inside the bounding box.
I surfed in google but could not get a proper guideline or reference, I would greatly appreciate any guidance, reference or samples in developing the above requirement in android native or flutter.