Who created these NFL pictures originally?

I'm from Germany and went to the USA on vacation. I like the Pittsburgh Steelers and went to an NFL Fanshop. There I found this picture as a poster:
I liked the style but this is not about the Steelers so I didn't really care about it. A few days ago I searched for the Steelers on google an found the same picture only in the version of the Steelers. Sadly I could only find out that these pictures exist for all 32 Teams but I didn't find any information about the creator of them so I can only find websites with low resolution pictures which are too small and have too bad quality to use them as a wallpaper for phone tablet pc or whatever. So I would like to know who is the original creator and is there any website with the original pictures or an official website which also sells these posters?
Asked Dec 04, 2013
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Answered Dec 06, 2013

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