Picasso said something like, "poor artists copy but great artists steal"! He meant you (the great artist) make the image your own by interpreting it in your own particular way (in my case here, an almost cartoonish style) taking an idea and doing it better! Use whatever you need for inspiration, take chances in your imagery but be an artist and a craftsman. (or craftswoman) Make something worth owning. I know I'm running counter to a lot of current art philosophy but I think an artist should produce something well that says something worth saying with materials used honestly (Yes, the Hand of the Artist!) and with respect for the work and ideas of others.
Following those rules you avoid any legal ramifications. BTW, everything on this blog is copyrighted! Actually, any work once published on the net has copyright protection. Yes, friends, there are people in this world who ignore those and take work directly - that is they really do steal - using other artists' images as if their own to make reputation or money. Gee, tell me it isn't so!
"Lots of people know a good thing the minute the other fellow sees it first." J. E. Hedges
"Xerox copies, Artists create." C.J. Rider