Those pictures are fake. There were giants but they weren't that big. They were about 6-9 feet tall. Don't forget that back then, people in general weren't as tall as people are today. Even back in the 1800's people weren't as tall as we are today. Better nutrition, vitamins, etc. has made as get taller each decade. So, when the people of the Old Testament mention giants, even somene who is 6'5" (height of a basketball player) would seem like a giant to them.