Camera plugin with custom preview?

hi, am searching for a camera plugin that i can customize the preview of the camera like showing some sequer to specify the required region or show some guides … any idea ?

you can not change the native camera-preview that simple. but you can add some crop-tool to manipulate the image afterwards.
I used, in some apps.

@bengtler what about using AR ? like enter link description here

a augmented reality sdk is a little bit different to select a part of an image.