Having onloadfinish error when loading image from SQlite Database

Hi I have saved the the image as a blob in my SQLite database:

public void onCreate(SQLiteDatabase db) {
    String sql =     "create table " + DATABASE_TABLE + " ( " +
                     FIELD_ROW_ID + " integer primary key autoincrement , " +
                     FIELD_LNG + " double , " +
                     FIELD_LAT + " double , " +
                     FIELD_ZOOM + " text , " +
                     FIELD_IMAGE + " blob " +
                     " ) ";

.....

public Cursor getAllLocations(){
    return mDB.query(DATABASE_TABLE, new String[] { FIELD_ROW_ID,  FIELD_LAT , FIELD_LNG, FIELD_ZOOM, FIELD_IMAGE} , null, null, null, null, null, null);
}

And then in my Main Activity when loading the data from SQLite:

@Override
public void onLoadFinished(Loader<Cursor> arg0, Cursor arg1) {
    int locationCount = 0;
    double lat=0;
    double lng=0;
    float zoom=0;
    byte[] bt = null;
    locationCount = arg1.getCount();
    arg1.moveToFirst();

    for(int i=0;i<locationCount;i++){

        // Get the latitude
        lat = arg1.getDouble(arg1.getColumnIndex(LocationsDB.FIELD_LAT));
        lng = arg1.getDouble(arg1.getColumnIndex(LocationsDB.FIELD_LNG));
        zoom = arg1.getFloat(arg1.getColumnIndex(LocationsDB.FIELD_ZOOM));
        bt = arg1.getBlob(arg1.getColumnIndex(LocationsDB.FIELD_IMAGE));
        thePoint = new LatLng(lat, lng);
        drawMarker(thePoint); 
        arg1.moveToNext();
    }


    if(locationCount>0){
        googleMap.moveCamera(CameraUpdateFactory.newLatLng(new LatLng(lat,lng)));
        googleMap.animateCamera(CameraUpdateFactory.zoomTo(zoom));
        ImageView image = (ImageView) findViewById(R.id.marker_icon);
        image.setImageBitmap(BitmapFactory.decodeByteArray(imageData, 0, imageData.length));

And when launching the app i can add the image, but when returning to the activity it crashes with this error:

01-04 10:51:03.995: E/AndroidRuntime(29156):    at com.test.testmap(TestingMap.java:347)
01-04 10:51:03.995: E/AndroidRuntime(29156):    at com.test.testmap.TestingMap.onLoadFinished(TestingMap.java:1)
01-04 10:51:03.995: E/AndroidRuntime(29156):    at android.support.v4.app.LoaderManagerImpl$LoaderInfo.callOnLoadFinished(LoaderManager.java:427)

Now at line 347 this is the code that is there is this:

image.setImageBitmap(BitmapFactory.decodeByteArray(imageData, 0, imageData.length));

CREATING THE BYTE[]

baos = new ByteArrayOutputStream();
           bitmap.compress(CompressFormat.PNG, 100, baos);
           imageData = baos.toByteArray();

Has anyone got an idea what i am doing wrong here? Thanks.

NOTE

at this line byte[] bt =null i get a warning under bt saying: The value of the local variable bt is not used but am not sure how to use it in my code when placing the image?