As stated before the same hd master that Arrow used was used for the recent French dvd/bd...
According to the French company Wild Side,the hd transfer was made in Italy under supervision of Storaro and then further restoration was done in France.
"Après la restauration et l’édition ces dernières années des chefs-d’œuvre Les frissons de l’angoisse et Suspiria (disponibles en DVD), Wild Side Films a procédé Ã* la restauration en haute définition de 4 œuvres majeures de Dario Argento : L’oiseau au plumage de cristal, Le chat Ã* 9 queues, Ténèbres et Phenomena.
Sous la supervision de Brigitte Dutray, directrice technique de Wild Side Films, les transferts HD ont été réalisés Ã* partir des négatifs originaux chez Technicolor Rome en
présence des chefs opérateurs de chacun des films, dont Vittorio Storaro et Luciano Tovoli. Les restaurations HD ont été effectuées par le laboratoire VDM Ã* Paris."
Babelfish roughly translates
:
"After the restoration and the edition these last years of the masterpieces the shivers of the anguish and Suspiria (available in DVD), Wild Side Films proceeded to the restoration in high-definition of 4 major works of Dario Argento: The bird with the crystal plumage, the cat with 9 tails, Darkness and Phenomena.
Under the supervision of Brigitte Dutray, chief technical officer of Wild Side Films, transfers HD were carried out starting from the negative originals at Technicolor Rome in the presence of the operators chiefs of each film, of which Vittorio Storaro and Luciano Tovoli. Restorations HD were carried out by laboratory VDM in Paris."