Image copyright Alexiz Connolly Image caption The army picture of Gary Connolly, from Campo, California, was restored after his daughter posted it on a Reddit forum. She first thought it was taken in 1976, later corrected by her dad to 1977

Before digital photography, many images were just snapped and printed once. If that picture became damaged, you had to live with it.

Alexiz Connolly, who lives on the Campo Indian Reservation, California, has one such photo - an army portrait of her dad taken in 1977 but now sadly creased and crinkled.

On Wednesday she posted the picture on the online Reddit community that shares photos of "history's cool kids".

"My dad's 60th birthday is on Friday and I was gathering his only young photos, one of which was his army photo," Alexiz, who works at a casino fixing slot machines, told the BBC.

When one user suggested she ask for Redditors' help in restoring the image to its former glory, Alexiz took the advice.

In under 12 hours, she had the results she hoped for - a smooth and clear portrait of her dad wearing his Ranger 1st Battalion fatigues.

"I'm in tears! Thank-you so much for this! I feel grateful that anyone would take the time to fix up his photo," Alexiz wrote to u/TheBlackPopeSJ, who edited the picture.

The heart-warming story also made people smile on Reddit, where it has been up-voted almost 45,000 times.

Image copyright Alexiz Connolly Image caption Gary Connolly, 60, officiating at his cousin's son's wedding on the Campo Indian Reservation, California. He is half Kumeyaay Native American.

"I'm overwhelmed by the love my dad's photo has got," Alexiz explained. "It's also given me the opportunity to ask my dad more questions about his time in the army."

Gary Connolly joined the US armed forces straight out of high school with his older brother in 1976, shortly after the Vietnam War had ended. He is now a Christian pastor.

Redditor u/DayGlowBeautiful commented on the story: "I'm in awe at your generosity of helping a random stranger on the internet with such an amazing gesture. This is what I hope the internet does for humanity, bring us all closer."

Another user explained how digital photo restoration is more difficult than it seems.

"You basically have to think of it as a million series of small skin grafts. It's much harder to create things that aren't there.

"Since that area isn't really similar to anything else, and most of the data is almost all gone, without basically just painting in something new, there's nothing to fix it with. "

Image optimisation and restoration is an increasingly popular trend, with historical pictures in particular inspiring photographers.

Artist Marina Amaral transforms black and white photographs taken as early as the 1860s by using digital techniques to add colour to black and white photographs.

Media playback is unsupported on your device Media caption Marina Amaral alters black and white photographs to build a bridge with history.

She recently used her skills to colourise a rare collection of photographs of British World War One nurses in an effort to trace their identities.

In August, pictures produced in 2010 by artist Seth Taras showing modern landmarks, such as the Eiffel Tower, spliced with historical images were shared almost 200,000 times on a Facebook art page.

Jordan Lloyd is another colourist who has turned his eye to history. Most of his work involves researching pictures and painting layers on to images that number from dozens to thousands.

And on Instagram, accounts such as History Coloured share historical pictures that can attract thousands of followers.