The images are copyrighted. You are not allowed to put it in the article unless you obtain an explicit (and preferably written) permission by the copyright holder to use it there. If you obtained a permission to use it for research and you would like to consider it a permission to publish it in an article, you better consult a lawyer, but the odds are that you can't do that. As well, do not forget to check whether the journal's copyright transfer is not conflicting with the permission you obtain from the picture's copyright holder. You'll very likely need an exception from the Editor to be allowed to use the image.
To see that this is an issue, remember that the usage of the famous Lenna picture led to legal complaints raised by PlayBoy who is the copyright holder. They decided to cancel the complaints, but it was just their choice. (Source: http://www.cs.cmu.edu/~chuck/lennapg/lenna.shtml)