The preview function for JPEG images is broken. It works fine for other image formats. I have enabled preview for jpeg files in the dolphin configuration dialog. Also, in the desktop settings dialog, the preview for wallpapers of jpeg type is broken.
I can still open jpeg images with gwenview/konqueror/okular and using wallpapers of jpeg type is also working.

I noticed that when I click on the configure button for jpeg preview in the dolphin preview configuration dialog, dolphin crashes.

My system: KDE 4.8 / QT 4.8 running on LFS.

Can you please run Dolphin in a application such as Konsole - so that the terminal output is captured? Please then post that output here - as it may contain helpful information.

One thing to check however - make sure your KDE Installation is fully up to date - and that the appropriate JPEG libraries were available at the time KDE was compiled if you self-compile it.

Thanks for your reply. The JPEG libraries were available when I compiled KDE, and, as I mentioned, I can still view JPEG images. It's only the preview function that's broken.
Here is the output when I run dolphin from the console:

Code: Select all

"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "QLocalSocket::connectToServer: Invalid name"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "QLocalSocket::connectToServer: Invalid name"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "QLocalSocket::connectToServer: Invalid name"
QPixmap::scaled: Pixmap is a null pixmap
QPixmap::scaled: Pixmap is a null pixmap
dolphin(1624) KSambaSharePrivate::findSmbConf: KSambaShare: Could not find smb.conf!
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "QLocalSocket::connectToServer: Invalid name"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "QLocalSocket::connectToServer: Invalid name"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "QLocalSocket::connectToServer: Invalid name"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "Invalid iterator."
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "QLocalSocket::connectToServer: Invalid name"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "Invalid iterator."
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "QLocalSocket::connectToServer: Invalid name"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "Invalid iterator."
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "QLocalSocket::connectToServer: Invalid name"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/kfilemetadatareader(1632)" Soprano: "Invalid iterator."
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "QLocalSocket::connectToServer: Invalid name"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "Invalid iterator."
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "QLocalSocket::connectToServer: Invalid name"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "Invalid iterator."
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "QLocalSocket::connectToServer: Invalid name"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "Unsupported operation (2)": "Invalid model"
"/opt/kde-4.8.0/bin/dolphin(1624)" Soprano: "Invalid iterator."

All the error messages concerning nepomukstorage are probably because I don't have the PIM apps installed since I don't use them. The two error messages concerning pixmap are interesting though.

When I press the configure JPEG preview button, Dolphin crashes with the following (useless) output:

Code: Select all

KCrash: Application 'dolphin' crashing...
KCrash: Attempting to start /opt/kde4/lib/kde4/libexec/drkonqi from kdeinit                                                                                                           
sock_file=/home/ragnar/.kde4/socket-mephisto/kdeinit4__0
                                                               
[1]+  Stopped                 dolphin

What backtrace does Dr Konqi generate, can you post that please?

The output error messages all concerned Nepomuk.
Another thing you could try running would be "kbuildsycoca4 --noincremental"

I tried re-installing kde-runtime, which fixed the problem...

This topic is from 2013, but the problem persists.