I've implemented a grid of Radiobuttons each having a unique image.
I've included relevant lines of code below:
photo[i] = ImageTk.PhotoImage(file=image_file)
button[i] = Radiobutton(frame, variable=var, value=i+1, indicatoron=0, image=photo[i], selectcolor='#808080')
button[i].pack(side=LEFT)
The image on OSX looks very pixelated as can be seen below:
The same code works just fine with ubuntu (no visible pixelation). Below is the original image: