Android setBackgroundResource cause out of memory excepiton

I'm working on a gamebook application that shows 12 views in a ViewPager. This is my custom PagerAdapter :

private class ImagePagerAdapter extends PagerAdapter {

    private int[] mImages = new int[] { R.drawable.copertinai,
            R.drawable.blui, R.drawable.azzurroi, R.drawable.rossoi,
            R.drawable.gialloi, R.drawable.verdei, R.drawable.rosai,
            R.drawable.grigioi, R.drawable.neroi, R.drawable.arancionei,
            R.drawable.marronei, R.drawable.violai, R.drawable.ulm };

    @Override
    public int getCount() {
        return mImages.length;
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view == ((RelativeLayout) object);
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        Context context = MainActivity.this;
        RelativeLayout relLayImageView = new RelativeLayout(context);
        relLayImageView.setBackgroundResource(mImages[position]);

        ((ViewPager) container).addView(relLayImageView, new LayoutParams(
                LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
        return relLayImageView;
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        ((ViewPager) container).removeView((RelativeLayout) object);
        object=null; 
        System.gc();
    }
}

In some devices it cause an out of memory exceptionr randomly when this line of code is called

relLayImageView.setBackgroundResource(mImages[position]);

But in all devices I see something like this in the logcat when i turn pages:

12-31 00:25:31.655: I/dalvikvm-heap(9767): Grow heap (frag case) to 50.875MB for 10384016-byte allocation

The app also crashes in some devices for the same problem when in another Activity I set different background resource to the main layout based on user action. Here the