private void sendBitmap(Bitmap bitmap) {
    // TODO - I'm in the pojo where I want to send the bitmap
}

import android.graphics.Bitmap;

public class MyActivity {

//  protected void whateverOtherMethods (Bundle savedInstanceState)
//  {
//      .
//      .
//      .
//      .
//      .
//      .
//
//  }

    /**
     * Callback interface used to supply a bitmap.
     */
    public interface MyCallback {
        public void onBitmapReady(Bitmap bitmap);
    }
}

private final MyCallback myCallback = new MyCallback() {

    @Override
    public void onBitmapReady(Bitmap bitmap) {
        // TODO - do something with the bitmap
    }
};

public class ProcessImage implements BitmapCallback {

/**
 * pojo method to return bitmap
 */
private void sendBitmap() {
    this.onBitmapReady(bitmap);
}

@Override
public void onBitmapReady(Bitmap bitmap) {
    // we still need to send the bitmap to cusomer App.

}

public interface BitmapCallback {

    public void onBitmapReady(Bitmap processedBitmapy);
}

private final BitmapCallback bitmapCallback = new BitmapCallback()
{

    @Override
    public void onBitmapReady(Bitmap bitmap) {
        // TODO Auto-generated method stub
    }
};

public interface BitmapCallback {
    public void onBitmapReady(Bitmap processedBitmap);
}

public Activity MyActivity extends Activity implements BitmapCallback {
    Handler mHandler; // initialize this in onCreate
    . . .

    public void onRequestImage() {
        ProcessImage processor = new ProcessImage();
        getImage(this /* , other actual args */);
    }

    @Override
    public void onBitmapReady(final Bitmap processedBitmap) {
        // since this may be called from a non-UI thread, we can't update
        // the UI directly.
        mHandler.post(new Runnable() {
            @Override
            public void run() {
                // handle the bitmap (update the UI, etc.)
            }
        });
    }
}

public class ProcessImage {
    public void getAnImage(final BitmapCallback callback /* , other formal args */) {
        new Thread() {
            @Override
            public void run() {
                Bitmap bitmap;
                . . . // do the work
                // then deliver the results
                callback.onBitmapReady(bitmap);
            }
        }.start();
    }
}

MyCallback callback;

private void sendBitmap(Bitmap bitmap) {
    // TODO - I'm in the pojo where I want to send the bitmap
    callback.onBitmapReady();
}