I recently did just that for a window display using my images - though playing from a USB stick in back of TV, instead of from a DVD - a 60" Sharp Aquous IIRC.
Though I wanted a fast turnover of images which is slightly different from your needs I guess. But this threw up some interesting issues.
Minimum Sslideshow speed was slower than I required and image quality was simply dreadful on video playback no matter how I adjusted set up. But despite not being able to really tweak slideshow image quality images looked much, much nicer than when used in TV mode.
So if playing images use the slideshow facility and a USB stick as you may get better images than when in TV mode [and not have to have a DVD player plugged into it]. I seem to recall other TVs I tested having similar quirks, so make sure you test how they work first and as a rule turn off all the image 'enhancement' features as they tend to do just the opposite. The Sharp was generally shocking as a TV as it happens with all sorts of weird motion artifacting even with motion smoothing type nonsense turned off.