The 38-year-old victim was attacked in Trafalgar Street as she tried to find a taxi at around 1.40am on January 1.
He was disturbed by passers-by during the attack and ran off in the direction of Vicar Lane.
Although the images are blurry, police are hoping someone will be able to identify the man, aged in his mid-twenties to early thirties, with short black hair and prominent sideburns.
Detective Constable Ian Johnson, of Leeds District Safeguarding, said: “We have been carrying out an extensive trawl of CCTV footage from a number of locations in the city centre and have produced images of the suspect running away.
“Due to the fact we have had to zoom in on much larger shots of the street, the quality of the images are not as clear as we would like them to be.
“They do however give a general impression of what the suspect looks like and together with the physical description, particularly the distinctive royal blue rucksack, we hope that someone may know who he is.”
The suspect was wearing dark jogging bottoms and a dark blue t-shirt and had a royal blue rucksack over his shoulders.
Anyone with any information is asked to contact DC 6610 Johnson at Elland Road via 101 quoting crime number 13160000009 or call Crimestoppers anonymously on 0800 555 111.