Note: 
    When you SELECT a bytea type, PostgreSQL returns octal byte values
    prefixed with '\' (e.g. \032). Users are supposed to convert back to
    binary format manually.
   
    This function requires PostgreSQL 7.2 or later. With PostgreSQL
    7.2.0 and 7.2.1, bytea values must be cast when you enable
    multi-byte support. i.e. INSERT INTO test_table (image)
    VALUES ('$image_escaped'::bytea); PostgreSQL 7.2.2 or
    later does not need a cast. The exception is when the client and backend
    character encoding does not match, and there may be multi-byte
    stream error. User must then cast to bytea to avoid this error.