The 76-year-old woman was robbed while walking on the Spen Valley Greenway on Monday afternoon.
She was struck to the back of the head with a hammer by a suspect who then escaped with her purse.
The suspect was described as a white man, slim, aged around 60, and wearing a woolly bobble hat and glasses.
Detective Sergeant Dave Taylor, of Kirklees CID, said: "We are conducting a range of enquiries to locate the man responsible for this serious offence and would like to speak to anyone who can identify the man pictured.
"We would also like to speak to anyone who may have seen a man matching this description in the town centre just prior to the attack."
Police previously said the woman was taken to hospital for treatment to a head injury and remained there overnight.
Her injury was not described as life threatening.
Anyone who with information or who recognises the man pictured is asked to contact Kirklees CID on 101, referencing crime number 13170207307.
Information can also be sent anonymously to the independent Crimestoppers charity on 0800 555 111.