Bitmap,Drawable,byte間的相互轉化

/**
	 * Drawable 轉 Bitmap
	 * 
	 * @param drawable
	 * @return
	 */
	public static Bitmap drawableToBitmapByBD(Drawable drawable) {
		BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable;
		return bitmapDrawable.getBitmap();
	}

	/**
	 * Bitmap 轉 Drawable
	 * 
	 * @param bitmap
	 * @return
	 */
	public static Drawable bitmapToDrawableByBD(Bitmap bitmap) {
		Drawable drawable = new BitmapDrawable(bitmap);
		return drawable;
	}

	/**
	 * byte[] 轉 bitmap
	 * 
	 * @param b
	 * @return
	 */
	public static Bitmap bytesToBimap(byte[] b) {
		if (b.length != 0) {
			return BitmapFactory.decodeByteArray(b, 0, b.length);
		} else {
			return null;
		}
	}

	/**
	 * bitmap 轉 byte[]
	 * 
	 * @param bm
	 * @return
	 */
	public static byte[] bitmapToBytes(Bitmap bm) {
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		bm.compress(Bitmap.CompressFormat.PNG, 100, baos);
		return baos.toByteArray();
	}