Far as I can tell, this photograph showing archaeologists working on the skeleton of a giant started to circulate on the internet in 2012. The most common claim is that it is one of several pictures of giant skeletons found in Sumeria.
Photoshop has become too easy to use, and people are — as ever — too willing to accept evidence that supports their beliefs. In this case the main people who put the image forward as evidence of giants either have books and websites devoted to the idea that giants once existed, or they are people who see it as confirmation of the phrase from the Bible that claims there were “giants in the earth.”
But, yes, this is a photoshopped image. The original image of the skeleton is that of one found by archaeologist David Billoin in Echenoz-le-Meline, France, on June 11, 2008, as part of a Merovingian necropolis that dates to the 6th century after Christ. As you can see in the images below, from the Getty Images website, the head shot is undoubtedly the one used for the image above… and the longer distance shot of the full body makes it clear it is not the scale of a giant.