The most used graphic program in the free software jungle is Gimp. It is a hugely powerful piece of software, but when all you want to do is to crop a JPEG image without any loss of quality, it's positive overkill: that's when you need CropGUI.
In my entomological work I often need to compare two images of bugs side-by-side.
Comparisons are surprisingly hard to do with either of the image viewers I normally use, namely Eye of Gnome and Ristretto. First I open two instances of the viewer and adjust their window sizes and positions for easy side-by-side comparison. I then open one image in one viewer window, and the other image in the other window. If I want to zoom in or out, or pan across the images, I have to do this independently in each viewer window. If I don't save this two-instance arrangement on a dedicated workspace using 'Save session on exit', I'll have to repeat the setting-up next time.
Comparisons are much simpler in Geeqie image viewer, which is now in most of the Linux distribution repositories. I first heard about Geeqie in 2011 when it was featured in a glowing online review. I hope this article adds to the glow.
If you've been following my column for the last year or two, you already know that "Lunatics" is the free-culture animated science-fiction series that we are creating with free-software applications like Blender, Synfig, Audacity, Inkscape, Gimp, and Krita. We are finally crowd-funding for our pilot episode "No Children in Space" on Kickstarter. If we get funded, this will be a major step forward for free-culture and free-software in the media industry. Come check it out, tell everybody you know, and/or get a copy on DVD or other cool stuff from the project!
I like tea. Well, I'm British. I've just discovered a new brand that I've never seen before. You can't dunk it in a cup of boiling water but it has some powerful features. This article explores two of the best.
Tea is a text editor. It's available in the Ubuntu repositories. If you're using another distro, try Tea's homepage. Text editors are ten a penny but Tea is different. When you first start it, you'll notice that the view mode is controlled by built in vertically-stacked tabs.
I recently wanted to export my email address book from Sylpheed email client and import it into my Gmail account. Unfortunately, Gmail wants to import contact lists as CSV files, and there isn't an export-address-book-to-csv feature in the otherwise wonderful Sylpheed. Worse, the Sylpheed address book is in XML format, and XML-to-CSV conversion isn't straightforward.
Warning: What follows contains code that may offend real programmers. The code works but it's pretty simple-minded, and if you're a real programmer and not a hobbyist hacker like me, you may not want to read any further.
There's been a lot of noise on the internet recently about the fact that the Windows-based software being used in the remote control system of drones use by the American military has been hit by a virus and this has caused the Department of Defense (DOD) to use GNU/Linux which is a more secure option. This has, predictably, caused raised eyebrows and demands by some that any military organisation should be prevented from using GNU/Linux in offensive weapons systems.
The GNU/Linux ecosystem is blessed with many tools to clone a hard drive image which can be used to reinstall your Debian-based distro in an emergency or duplicate on another machine, but sometimes you might want to do a clean install of Ubuntu on another machine and then add in the extra software you installed in the original distro. For that you need a combination of Synaptic, the GUI frontend for
apt-get and a little command line magic.
There is no shortage of backup software in GNU/Linux. From full clones of hard drives to browser bookmarks there's something for everyone. However, sometimes you just need to be more selective about what you backup.
If you want to backup your precious desktop settings, you should try Ubuntu Tweak: it is bundled with a host of really useful features, it's been around for a while and it's up to version seven. You might find a version in your distro's repositories but if you're out of luck, download it from the official site.
Last week I finally took the leap and did an online upgrade from Ubuntu 11.10 to 12.04 (Precise Pangolin). To my relief it was a flawless operation and one of the things I wanted to experiment with the much hyped HUD feature which is being slated as a replacement/supplement to application menus. It's a Marmite feature. You either love it or loathe it but what caught my attention was the keybinding used to launch it and how this interacts with its "near neighbours".
People like Dolphins. They're fast and smart and swimming with them is on many people's "ten things to do before you die" list. Not me though. The nearest I'll ever get to a Dolphin is the one sitting on my laptop -- the Dolphin file manager that is. It's nippy too but I find that I can speed it up even more by using keybaord shortcuts.
One of the first things that newcomers to GNU/Linux learn to do is to bypass big Start menus and blank screens (like Fluxbox) and use
ALT+F2 to launch an application by simply typing in its name. Every desktop ecosystem has its own way of implementing this feature and I was pleasantly surprised, after a long absense from the KDE desktop, to see how it could be used to do some really clever things. Here's five of them.
The concept of the right-click context menu has been around since forever but you don't have to be content with the defaults that come with your software, especially file managers. KDE's Dolphin and Konqueror are no exceptions. It's a complete no brainer to install more contextual menus, so let's do it.
Adding menus works exactly the same way in both managers (the only difference is that Konqueror is also a web browser too). I'm using Dolphin today. So, fire it up and select
Configure Dolphin from the drop-down Settings menu.
When you build or update a website, it's a good idea to check that all the links on your webpages are OK. An excellent tool for doing this under Linux is the aptly named linkchecker, a GPL-licensed, command-line program.
However, 'OK' has more than one meaning. While linkchecker can check the URL you specify to see if it's properly formed and not broken, it can't tell you if the link points to the wrong URL.
Newcomers to Ubuntu will only really know about installing software via the Ubuntu Software Centre. Synaptic is no longer bundled by default (though still available) but all us, veterans and newbies alike, should also consider installing Deepin. It's similar to Ubuntu's tool but it has some really nifty and useful features.
Okular is the PDF reader for the KDE desktop. You can run it under any other desktop environment too, but you can also get some more mileage out of it with these three simple tips.
PDFs are very common and popular but with the rise of smartphones and tablets the EPUB format has risen to prominence too. Okular has some very neat features not available to other PDF readers and you might want to combine them with this relative newcomer on the block.
h5ai is a "modern web server index." What's that, you may ask? Basically, it's a simple software that prettifies the default interface the Apache web server uses to list files in a directory. This may not sound like much, but if you want to publish files on the web using Apache (or any other supported web server, for that matter), this unassuming tool can make the whole experience of browsing and downloading files more pleasant -- which is a positively good thing.
For my money Calibre is one of the most indispensible pieces of software in GNU/Linux. It can handle all your e-books in all the major formats, including PDF, EPUB and Mobi. It supports up to thirty e-reader devices but this article will tell you how to use Calibre to convert RSS feeds to EPUBs (which can then be read in Calibre's own E-reader or synced and transferred to your external reader of choice).
My wife has a huge collection of Scottish country dancing music on her Linux laptop – more than 2000 dance tracks. Details of all tracks are recorded in an OpenOffice Calc spreadsheet.
She asked me, "Could you make the spreadsheet into a jukebox, so that I could do a filtered search for a suitable track, then just click on the track to have it play?" The answer was yes, but it took a while to get there!
Gwenview is the default image viewer for the KDE desktop. Out of the box it's good looking but nothing obviously exceptional. Except for two things: Phonon and plugins. That combination really does make Gwenview a pretty useful bit of kit. Let's see what it can do.
In my last article on Chromium I explained how to add a command switch to the desktop icon's launcher tab to add a Purge Memory button to the task Manager. Browsers need memory, like memory and in fact love it. They don't give it up without a fight. I'm not belligerent by nature but it's my memory, I paid for it and I want it back. So, here's another trick in a similar vein to force Chromium to relinquish some more.