option1 = using built in camera app and Bitmap to do your own image processing
option 2 = (not shown see lecture on cameras in android) you integrate the taking of picture inside your app and then like option 1 get a Bitmap to do your own image processing
option 3 = use OpenCV framework for Java that lets you take pictures and process them using build in "library" of already created Image Processing and Analysis algorithm << I like this the BEST