Android: Question about Bitmaps, memory usage, and scaling

For readibility, I posted the code examples that my solutions refer to first, and thenI listed the explanations of my solutions in a numerical list.

I have been struggling with this for a while now. I have done much reading, asked questions on here, and experimented; but have not come up with a decent solution. I need to read variously sized images from input streams, and display them with as high of quality as my memory constraints allow. Below are the options I have considered, none of which seem great to me. Any help or input would be greatly appreciated.

 public class NativeTest extends Activity
 {
    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
       super.onCreate(savedInstanceState);
       double nativeUsage = Debug.getNativeHeapAllocatedSize(); 
       Log.i("memory", nativeUsage+"");
    } 
 }


 double getAvailableMemory()
 {
    //current heap size 
     double heapSize =  Runtime.getRuntime().totalMemory();
    //amount available in heap 
    double heapRemaining = Runtime.getRuntime().freeMemory();   
    double nativeUsage  =  Debug.getNativeHeapAllocatedSize();
     double memoryAvailable = Runtime.getRuntime().maxMemory() - (heapSize - heapRemaining) - nativeUsage;
    return memoryAvailable;
 }

Bitmap createImageTrialAndError(InputStream stream)
{
    Bitmap image = null;
    int dowsample = 1;
    while(image == null)
    {
       try
       {    
        Options opts = new Options();
        opts.inSampleSize =  downsample;
        image = BitmapFactory.decodeStream(imgStream, null, opts);
       }
       catch (OutOfMemoryError ome)
       {
           downsample = downsample * 2;
           Log.i("out of mem", "try using: " + downsample); 
       }
    }

    return image;
}

1. The ideal solution would be if Bitmap had a Bitmap.drawBitmap(inputstream...) method. This would allow me to draw from the inputstream without having to allocate memory for the Bit