XNView did crash with my selection of Baidu wallpapers.

There are likely some corrupt images within. That's usually the only thing that will crash an image viewer. Note that it's also possible for images to contain binary code that attempts to overflow the buffer of an image routine and run on the local machine. Something to keep in mind if you did acquire these from Baidu. The Chinese government used Baidu to attack github last month, so other modes of attack are certainly possible.