What fast image viewers are available for Ubuntu?
Solution 1:
GPicView
I'll recommend to you this Simple and Fast image viewer.
As you say that you computer is not a super fast calculator you should look for software with a few functions (the fewest possible), and this software meets this requirement, see the next screen-shoot and you will notice it.
You can install it through the Software-Center.
Solution 2:
For sheer speed, feh is the most responsive image viewer you'll ever come across; it might take a bit of getting used to as it is managed from the command line. However, you can add various feh commands as custom actions to filemanagers such as Nautilus and Thunar so that you can activate feh via the context menu when browsing your files.
On the man page it is noted that:
Feh is a mode-based image viewer. It is especially aimed at commandline users who need a fast image viewer without huge GUI dependencies, though it can also be started by (graphical) file managers to view an image. It supports filelists, various image sorting modes, image captions and more... Configurable keyboard shortcuts are used to control it.
Some examples of usage:
Feh operates in various modes such as slideshow, montage, index, and thumbnail, although you can of course view pictures individually, and also save the results of the index or thumbnail viewing to file.
All the following examples assume you use terminal to cd to the folder containing the pictures first:
1) To start a fullscreen slideshow, and for it to display all the loadable pictures in the folder with a 3 second gap and then exit, you could run:
feh -F -D 3 --cycle-once *
You can use your mouse scrollwheel to flick back and forth through the pictures while the slideshow is running. Even with high resolution pictures (5-6 mb each), you can flick through the pictures incredibly quickly.
You could also add this command, with slight modification, as a 'custom' action, context menu item in a file manager such as Thunar (feh -F -D 3 --cycle-once %F): see my answer here regarding Thunar custom actions.
Note: when not running in fullscreen mode (-F), you may need to supply the --scale-down command switch so the pictures fill your desktop, but not display at their actual size (which could be 4000x3000 and would not fit the screen).
feh --scale-down picture.jpg
Hence your custom 'open-with' command/launcher should use this --scale-down option, for the times you want to view individual pictures.
2) In the case of creating an index print and saving to file you could use the following command:
feh -I --preload -o index.png
3) You can also use the thumbnail option (-t), which is like the previous command, but allows you to click the thumbnails from the created file:
feh -t --preload --scale-down -o thumbprint.png
You can do a lot more with feh and there are many more options to experiment with, so for more information, please see man feh and the Ubuntu manpages online.
Solution 3:
Viewnior
Viewnior has been the fastest image viewer for me by far:
One more reason to choose Viewnior is that isn't affected by this image scaling bug that's prevalent in many other GTK-based image viewers (see here for other solutions to this bug).
Installation
Ubuntu 14.10 and up
As of Ubuntu 14.10 Viewnior is now part of the official Ubuntu repositories. You can install it from the Software Centre or by running the following command:
sudo apt-get install viewnior
Earlier Ubuntu releases
A third-party PPA for Viewnior is now available. Before proceeding with the installation please make sure to read the following Q&As on PPAs and their potential dangers:
What are PPAs and how do I use them?
Are PPA's safe to add to my system and what are some "red flags" to watch out for?
If you are confident with adding a third-party PPA you can install Viewnior by using the following commands:
sudo add-apt-repository ppa:desdelinux/viewnior
sudo apt-get update
sudo apt-get install viewnior
Source: http://blog.desdelinux.net/instala-viewnior-en-ubuntu-12-04-13-10-14-04-ppa/
Alternatively you can compile Viewnior from source:
git clone https://github.com/xsisqox/Viewnior.git
cd Viewnior
./autogen.sh
./configure
make
sudo apt-get install checkinstall
sudo checkinstall
Instead of using checkinstall to generate a debian package and install it via the package manager you can just as well run make install. With this method you won't be able to manage your installation from the package manager, though.
Solution 4:
That's quite sad, but the fastest viewer for my PC (mobile core i5 2nd gen and ssd) is Picasa installed in Wine. I've compared following viewers while browsing quickly through hundreds of 3MB jpgs:
- Picasa 3.9 in Wine - instant (yes, if browsing very quickly you may see previews in lesser quality, but you still don't have to wait, while it's loading, as in every other viewer mentioned below)
- XNViewMP 0.72 - faster than "very fast" but slower than instant :)
- Viewnior 1.4-2 - very fast
- GPicView 0.2.4-1 - fast
- gThumb 3:3.3.1 - average
- Eye of GNOME 3.12.2 (default on Ubuntu) - terribly slow
- Shotwell Viewer 0.20.2 - terribly slow
P.S: PicasaPhotoViewer.exe is actually a viewer, not Picasa3.exe
Solution 5:
Mcomix actually not a traditional "image" viewer but a comic reader but since it preloads all pictures in a folder/zip/rar/whatever it is instant when switching pictures (turing a page) + there is a small preview on the side where one can see which pictures are already preloaded