Detect dark image application: code that needs fixing -- 2

Due to work related travel , I had postponed this project for my hobby.

I am reopening it again to get help with fixing the code of a simple app that checks the front camera for when the image goes dark. ( suggest code provided )

Requirements:

-Must be an Eclipse format file

-Single screen app

- The threshold value should be kept in a variable that i can change for testing.

- Must have a method/function with the code to be executed when the threshold is reached (see example below - onPreviewFrame() ). For testing it should just show a popup with the current luminance value.

- It should work with the lowest Android version possible (anything Gingerbread or higher hopefully )

That is it. I hope this is as simple as i think and welcome any suggestions regarding this posting.

I found an example in Stackoverflow that might get it started:

[url removed, login to view]

----- from stack overflow --------

This is fairly straightforward. You should use a surfaceview and camera preview. That way you get each frame as a byte array. The default format for the frame is YUV, which is Y (luminance) and UV, which are chrominance. You can use Y to calculate average luminance in the image. If you're using BGR, you can calculate luminance using: Y = 0.2126 R + 0.7152 G + 0.0722 B

class Preview extends ViewGroup implements [url removed, login to view] {

SurfaceView mSurfaceView;

SurfaceHolder mHolder;

Preview(Context context) {

super(context);

mSurfaceView = new SurfaceView(context);

addView(mSurfaceView);

// Install a [url removed, login to view] so we get notified when the

// underlying surface is created and destroyed.

mHolder = [url removed, login to view]();

[url removed, login to view](this);

[url removed, login to view](SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

}

... }

adding the callback to your class, means for every frame this method is called:

onPreviewFrame(byte [] frame, Camera cam){

//do some processing

//

}

--- end of stackoverflow -----

Android Mobile App Development

ID do Projeto: #6498306

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