LIKE or match by beginning for binary strings in PostgreSQL

I need to match a binary column with its beginning. For text columns it's easy: LIKE 'image/%'. This uses BTREE index if any. Is it possible to do this also using an index for a binary column? BTW, I store UTF-8 encoded strings in Binary, because there is no hard standard that all of them are UTF-8. So, I store a binary representation (maybe even with \0 (zero) bytes), as I cannot use UTF-8.