BitmapFactory.Options options=new BitmapFactory.Options();

    options.inJustDecodeBounds = false;

    options.inSampleSize = 10;   //width，hight设为原来的十分一

return BitmapFactory.decodeFile(imgPath,options);

options必加上

最后再回收

@Override

protected void onDestroy(){

if(b!=null){

b.recycle();

System.gc();

}

}