The offence occurred around 11.45pm on Sunday, August 27 when three male victims were approached by a group of unknown males as they walked along Commercial Street.
One man was punched to the face causing him to fall to the floor, where he was then kicked. He sustained serious injuries and was treated in hospital.
The culprits then assaulted the victim's two friends, and both suffered minor injuries.
Officers are appealing for anyone who may know the identity of those pictured in the CCTV images, or who may have witnessed any part of the incident, to come forward with any information.
Information can be passed to PC Natasha Butterfield at Calderdale CID via 101 quoting 1317. Information can also be passed anonymously to Crimestoppers on 0800 555 111.