Camera API working on Jelly Bean but not Kitkat

I have observed that you are not assigning any surface holder to the camera. Giving a preview surface to the camera is important.

According to the docs here:

http://developer.android.com/guide/topics/media/camera.html

follow the code suggested by the doc. Taking a picture without a preview is a big security concern. Android guys might have fixed this in kitkat.

You might have missed that part of the code while pasting here so as an added concern also check that you are executing your code 'camera.takePicture(null,null,callback)' inside the callback method 'onSurfaceCreated' of SurfaceHolder.

You can get all the relevant code at aforementioned link.

KitKat's garbage collection works differently than previous APIs.

I'm guessing that the PhotoHandler object that you pass to the takePicture() method is getting garbage collected before onPictureTaken can be called.

Try making a PhotoHandler object as in instance variable in your MainActivity.

At the top of the class:

PhotoHandler photoHandler;

Then in onCreate()

photoHandler = new PhotoHandler(getApplicationContext());

Then when you call takePicture():

camera.takePicture(null, null, photoHandler);