In order for a work protected by copyright to be digitally published on the Internet by a library or archives, it is imperative that the right holders give their prior consent.
However, regarding orphan works, it is considered that the right holders have not been identified despite diligent research. Thus the consent of such right holders cannot be received to digitize and publish such works.
The February 20th 2015 Act implementing EU Directive n°2012/28/EU on certain permitted uses of orphan works clarifies the question of the means of publication of orphan works.
The texts now stipulates that libraries can digitize such works and make them available to the public (under new articles L. 135-1 et seq. of Intellectual Property Code) in order to ensure their circulation on a non-profit basis for purposes of education, preservation and broadcasting of cultural heritage.