Emil Mariot 1867 "heliogravure" proccess.. "A photographic gelatin relief was transferred to a silver-surfaced copper plate, whereon an intaglio printing surface was produced by photogalvanography." (Mertle pg. 23) The process may have also been used for photographs as this one example exists. 
This book is a history of Photogalvanography by Pretsch, with full instructions and contemporary uses as well as discussion of other modifications, such as Mariot’s. Two samples of Mariot’s process, one a photogravure plate produced in 1869 and a photogravure portrait of Pretsch, 2 Photogalvanographs from Pretsch plates, one intaglio, one relief (both art), 2 Mariot Photo-Galvanogravures, one of scenery from 1869, one a map, 3 half-tones by Husnik, one from art, 2 from life.
Hanson, David A. Checklist of Photomechanical Processes and Printing, 1825-1910. , 2017. p. 88.
 Hanson, David A. Checklist of Photomechanical Processes and Printing, 1825-1910. , 2017. p. 88.
Volkmer, Ottomar. Die Photo-Galvanographie Zur Herstellung Von Kupferdruck Und Buchdruckplatten: Nebst Den Dazu Nöthigen Vor Und Nebenarbeiten. Halle a.S: W. Knapp, 1894.