android 根据分辨率对图像进行缩放

mDDpi = 0xF0;
mDpi = 0xA0;

if (mDDpi != mDpi) {
	float perc = (float) mDpi / (float) mDDpi;
	int width = (int) (org.getWidth() * perc);
	int height = (int) (org.getHeight() * perc);
	org = Bitmap.createScaledBitmap(org, width, height, true);
}
Drawable draw = new BitmapDrawable(getResources(), org);