I wasn't able to find a good slide show program for the Raspberry Pi, so I wrote my own.
Just compile with cmake and supply an .ini file (see below). Remember to copy the qt plugins directory "imageformats" here.
Supply a PhotoViewer.ini file with these fields:
;# where the photos are, this one pretty much required, others optional
Directory=""
;# If true, sleep for 1/2 the display time (give up the CPU). This is for ;# the Raspberry Pi (it was getting hot). Default false. ;# Program will be un-responsive of course.
SleepMode=
;#Time to show each photo, default 30 seconds.
DisplayTime =
;#Display the file name, default true.
DisplayFileName =
;#Fullscreen (default) or Windowed
Fullscreen =
;#Random mode, default true
Random =
;#Hide the curor, default true
HideCursor =
;#name of file to save list to NamesFile = "names.txt"
;# bool to save names SaveNames =
;# bool to read names ReadNames =
EXIF Orientation code copied from: https://www.eastfist.com/qt_tutorials/index.php/2017/02/07/how-to-read-exif-orientation-from-jpeg-in-qt-4-8-5/