If you use it to manage your photos and like it easy I recommend to use Shotwell, which should be installed by default.

Open it:

Select the photos you want to be set as background slideshow:

Open File → Set as Desktop Slideshow or press Ctrl+B:

Adjust time settings:

Done.

Wallch

In software center there are two wallpaper changer - wallch for Gnome-Shell/Unity/Gnome-Classic and Wally for KUbuntu.

Lets concentrate on Wallch.

Sadly the version of Wallch in the software centre is outdated and has many issues especially with 14.04! There's a repository with the recent version.

To install, add the repository (you don't need to do this on 16.04):

sudo add-apt-repository ppa:wallch/wallch-daily

Then install Wallch:

sudo apt-get update && sudo apt-get install wallch

Then start from Dash:

Lets now launch the application preferences:

Let's untick the bubble notification - its annoying - at the same time you could disable sounds!

At the same time you can define the start-up options:

Save - and add a folder of pictures - in this example, use /usr/share/backgrounds for the default wallpapers that come with Ubuntu

Now we've got two choices:

Start up choice 1

(thanks @Naruto)

keep wallch in in the launcher

exit wallch and start changing wallpapers

Start up choice 2

start wallch on login without needing to have a launcher

From the dash:

Then create a new startup application with the command wallch --constant

N.B. - for some computers this will not work. The solution is to introduce a delay to the startup of the wallch daemon as per the following Q&A:

Wallch not auto-cycling backgrounds on log in

For 11.04 and previous versions

There's a program for creating wallpaper slideshows called CREBS. Check out this article about it: http://www.omgubuntu.co.uk/2010/05/crebs-the-ultimate-wallpaper-slideshow-application

A simpler app that has fewer features but is easier to use can be found here: http://gnome-look.org/content/show.php/Wallpaper+Slideshow?content=125178

  Variety

Homepage: http://peterlevi.com/variety
Github: https://github.com/varietywalls/variety

Variety is a wallpaper manager for Linux systems. It supports numerous desktops and wallpaper sources, including local files and online services: Flickr, Wallhaven, Unsplash, and more.

Where supported, Variety sits as a tray icon to allow easy pausing and resuming. Otherwise, its desktop entry menu provides a similar set of options.

Variety also includes a range of image effects, such as oil painting and blur, as well as options to layer quotes and a clock onto the background.

Install

It's available in the Universe repo. To install it, run

sudo apt install variety

Also you can install it from Peter Levi's PPA by running

sudo add-apt-repository ppa:peterlevi/ppa
sudo apt-get update
sudo apt-get install variety

Create an XML file yourself. Use this script as a starting point with caution, it may have some errors.

#!/bin/bash

FILE="background.xml"
DURATION=10.0
TRANSITION=0.0

CURRENTDIR=$PWD
TRANSITION_XML="
<static>
    <duration>$DURATION</duration>
    <file>$CURRENTDIR/%s</file>
</static>
<transition>
    <duration>$TRANSITION</duration>
    <from>$CURRENTDIR/%s</from>
    <to>$CURRENTDIR/%s</to>
</transition>
"

# Random order
shopt -s nullgob nocaseglob        # ignore non-existant extensions, case-insensitve
IMGS=( *.{jpg,jpeg,png,gif} )
INDICES=( $(shuf -e ${!IMGS[@]}) ) # randomize indices of images
INDICES+=(${INDICES[0]})           # go back to first image after last
COUNTER=${#IMGS[@]}

exec > "$FILE"                     # all further output to the XML file
echo "<background><starttime></starttime>"

for ((i = 0; i < COUNTER; i++))
do
    index=${INDICES[i]}
    printf "$TRANSITION_XML" "${IMGS[index]}" "${IMGS[index]}" "${IMGS[index + 1]}"
done

echo "</background>"

Instructions:

Once the background.xml file has been generated, right-click on the desktop, select Change Background Image, click Add..., then navigate to the directory containing the XML file. Just above the "Open" button change the selector from "Image" to "All files", then select the background.xml file and click on the "Open" button. The file can be renamed to be more descriptive, such as my_family.xml, landscapes-3.xml, etc., allowing one to have multiple slide show playlists.

For gnome 3, generate the xml using one of the previous answers, then you could add the generated xml via the command line:

gsettings set org.gnome.desktop.background picture-uri 'file:///home/pykler/.backgrounds/realtime/background.xml'

Another Solution (this will add your bg to the Appearance area under gnome-control-center):

mkdir -p ~/.local/share/gnome-background-properties/

cat >~/.local/share/gnome-background-properties/custom-wallpapers.xml <<EOF
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE wallpapers SYSTEM "gnome-wp-list.dtd">
<wallpapers>
  <wallpaper deleted="false">
    <name>Pykler</name>
    <filename>/home/pykler/.backgrounds/realtime/background.xml</filename>
    <options>zoom</options>
  </wallpaper>
 </wallpapers>
EOF

Replace the name "Pykler" and the path "/home/pykler/.backgrounds/realtime/background.xml" as needed.

For Gnome 3, you can use the Wallpaper Slideshow App.

According to its developer, it has the following features:

• Lets you choose the folder via a browser.
• Lets you set the timeout in seconds.
• Lets you chose depth of subdirectory.
• You can enable or disable it with a single click.
• Full-feature tooltips

To download:

git clone git://gitorious.org/gnome-3-wp/gnome-3-wp.git

Then run wp-show in the gnome-3-wp folder in your home folder.

For more information, see here and here.

Use cortina, it works pretty well.

It can set the desktop background picture to be set a random file from a given directory.

It can be installed via Ubuntu Software Center.

Ok here is how I did it, which is probably not the best way to do it but it worked and I didn't have to install anything to do it. Back in 11.10 I found the below python script (slideshow.py) which generates a slideshow.xml file (run from directory with the images in it). This is still the file needed in 12.04 but you also need another XML file. Put the XML file generated by slideshow.py script in /usr/share/backgrounds/contest and chown it to root. Once that is done you'll need to run the second python script (wallpapers.py) which was adapted from the first. Put the file generated from wallpapers.py in /usr/share/gnome-background-properties and again chown it to root. At that point you should be able to go into "System Settings" -> Appearance and pick your slideshow or any of the pics in it.

slideshow.py:

#!/usr/bin/env python
#coding=utf-8
# slideshow.py
import glob, os
import shutil
import time
import Image

filelist=[]
def filelie(path):
    if os.path.isfile(path):
       wenjian=os.path.splitext(path)[1][1:]
       if wenjian=="jpg" or wenjian=="png" or wenjian=="gif":
        try:
          kuan,gao = Image.open(path).size
          if kuan>=1024 and gao>=768:
            filelist.append(path)
        except IOError:
         pass
    elif os.path.isdir(path):
        for item in os.listdir(path):
            itemsrc = os.path.join(path, item)
            filelie(itemsrc)

curdir = os.getcwd()
filelie(curdir)
currentImageFiles = filelist
#print filelist
if os.path.isfile('slideshow.xml'):
 os.remove('slideshow.xml')


currentTime = time.localtime()
length = len(currentImageFiles)

f = file('slideshow.xml', 'w')

f.write('<background>\n')
f.write('\t<starttime>\n')
f.write('\t\t<year>' + str(currentTime.tm_year) + '</year>\n')
f.write('\t\t<month>' + str(currentTime.tm_mon) + '</month>\n')
f.write('\t\t<day>' + str(currentTime.tm_mday) + '</day>\n')
f.write('\t\t<hour>' + str(currentTime.tm_hour) + '</hour>\n')
f.write('\t\t<minute>' + str(currentTime.tm_min) + '</minute>\n')
f.write('\t\t<second>' + str(currentTime.tm_sec) + '</second>\n')
f.write('\t</starttime>\n')
f.write('<!--This animation will start at the time it created-->\n')

for i in currentImageFiles:
 length = length - 1
 f.write('\t<static>\n')
 f.write('\t\t<duration>96.0</duration>\n')
 f.write('\t\t<file>' + currentImageFiles[length] +'</file>\n')
 f.write('\t</static>\n')
 f.write('\t<transition>\n')
 f.write('\t\t<duration>3.0</duration>\n')
 f.write('\t\t<from>' + currentImageFiles[length] + '</from>\n')
 if length >= 1:
  f.write('\t\t<to>' + currentImageFiles[length-1] + '</to>\n')
 if length <1:
  f.write('\t\t<to>' + currentImageFiles[len(currentImageFiles)-1] + '</to>\n')
 f.write('\t</transition>\n')

f.write('</background>\n')
f.close()

wallpapers.py:

#!/usr/bin/env python
#coding=utf-8
import glob, os
import shutil
import time
import Image

filelist=[]
def filelie(path):
    if os.path.isfile(path):
       wenjian=os.path.splitext(path)[1][1:]
       if wenjian=="jpg" or wenjian=="png" or wenjian=="gif":
        try:
          kuan,gao = Image.open(path).size
          if kuan>=1024 and gao>=768:
            filelist.append(path)
        except IOError:
         pass
    elif os.path.isdir(path):
        for item in os.listdir(path):
            itemsrc = os.path.join(path, item)
            filelie(itemsrc)

curdir = os.getcwd()
filelie(curdir)
currentImageFiles = filelist
#print filelist
if os.path.isfile('mywallpapers.xml'):
 os.remove('mywallpapers.xml')


currentTime = time.localtime()
length = len(currentImageFiles)

f = file('mywallpapers.xml', 'w')

f.write('<?xml version="1.0" encoding="UTF-8"?>\n')
f.write('<!DOCTYPE wallpapers SYSTEM "gnome-wp-list.dtd">\n')
f.write('<wallpapers>\n')
f.write('\t<wallpaper deleted="false">\n')
f.write('\t\t<name>My custom Wallpapers</name>\n')
f.write('\t\t<filename>/usr/share/backgrounds/contest/slideshow.xml</filename>\n')
f.write('\t\t<options>zoom</options>\n')
f.write('\t</wallpaper>\n')

for i in currentImageFiles:
 length = length - 1
 f.write('\t<wallpaper>\n')
 f.write('\t\t<name>' + os.path.basename(currentImageFiles[length]) +'</name>\n')
 f.write('\t\t<filename>' + currentImageFiles[length] +'</filename>\n')
 f.write('\t\t<options>zoom</options>\n')
 f.write('\t\t<pcolor>#000000</pcolor>\n')
 f.write('\t\t<scolor>#000000</scolor>\n')
 f.write('\t\t<shade_type>solid</shade_type>\n')
 f.write('\t</wallpaper>\n')

f.write('</wallpapers>\n')
f.close()

You might be interested in a program that automatically creates such a wallpaper-slideshow.

According to this OMG! Ubuntu post, you have for example 'Wallpaper Gallery'. It takes as input data tagged photos from your Shotwell gallery. Therefore it becomes very easy to add & remove photos for instance.

First select the tags concerning the photos you want to be displayed, then configure as you wish the switching time, the order, etc. Here some screenshots :