After few super-busy weeks I finally have time to sit down and write another part of this blogseries. In this installment I'll introduce Gwenview - the default KDE Application for viewing images.
With this great application you can open pretty much any image format you can find, including Photoshop, GIMP, PCX, EPS and much more (I don't have to mention JPEGs, PNGs, GIFs, TIFFs..right?). Thanks to Phonon integration, Gwenview can even play videos for you. Just imagine browsing pictures from your camera's memory card, where you have both pics and videos - why open other application for videos? Gwenview does it for you. If you don't like Gwenview showing you videos, there's an option to disable it.
Just recently Gwenview gained some nice OpenGL effects like crossfading when changing image or some subtle animations when selecting files. This will be available in the upcoming KDE Workspaces and Applications release, 4.8. I've been using it ever since and it's working great, but nothing is perfect and if you encounter any bugs or problems with this new feature, I'd like to encourage you to report it at http://bugs.kde.org.
When you open Gwenview from the applications menu, the first screen that greets you contains list of recently opened folders (in Gwenview), sorted by the last open date, and also the famous 'Places' sidebar, containing the exact same entries as the one in Dolphin (or open/save dialog) for easy navigation. Gwenview can also open and show images from remote URLs (remember KIO?) and you can display the URLs you visited in the 'Recent URLs' tab. The 'Places' sidebar has also a second tab - 'Tags', where you can display content sorted by semantic tags.
Once you select anything from this 'Start page', Gwenview switches to the 'Browse mode'. Here you can simply browse the selected folder, navigate to others using the same breadcrumbs as in Dolphin or by using a 'Places tree' sidebar. When you hover over any image in the 'Browse mode', a small set of buttons appears above the image - these enable you to add that particular image into selection, show it in fullscreen or rotate it left or right. The statusbar of 'Browse mode' contains a filtering menu, shows how many images you have in the current folder and a zoom slider, which controls the thumbnails size in the view.
As mentioned above, 'Browse mode' features advanced filtering - you can use name filter, date filter, tag filter or rating filter or combinations of all. With name filter you have two options - set what the image name should contain or the opposite; filter images with the searched word not in their name. Date filter is also clear - display images with date lesser than, equal to, or greater than the date you select from calender widget. Rating filter - just what you'd expect - less than, equal to, more than the rating you select. Tags - same as names - you can select "tagged with a tag" or "not tagged with a tag". For filtering by more tags, simply add more filters. You can very easily remove any filter you want - just click the little close button next to it and it's gone.
Gwenview houses one hideable sidebar with three tabs. The first one is the 'Places tree' (captioned 'Folders' on the tab) and it is used solely for navigation purposes.
The second tab is 'Information' sidebar and it serves for displaying various informations about the selected image. It has two parts - meta information and semantic information. Meta info comes from exif tags (but also IPTC and XMP, which are both extension of exif) and you can configure which exif data to show - for example exposure time, lens model, if flash was used, used aperture etc. You can also select general file information like file name, file size, time of creation or image resolution. The semantic part lets you enter semantic info - rate the image, set tags and add a comment. You don't have to save it anywhere, it is processed immediately without the need to explicitely save these data.
The last tab - 'Operations' - lets you do basic operations with image or file. The difference being image data and the file in filesystem itself. You can mirror, flip or resize images when in 'Browse mode', but once you switch to 'View mode', two more operations are added - crop and red eye reduction (these would be obviously impossible to do in 'Browse mode'). As for file operations - you can find the usual like rename, move to trash, remove completely (bypass trash), copy to, move to, link to (these last three pops up a 'save file' dialog, so you can select the place and copy/move/link it right away) or open with menu, which contains the system file associations. Lastly this sidebar will let you open a dialog with all file properties like from Dolphin and create new folder.
View mode & Fullscreen mode
The 'View mode' is just what you'd expect - a view mode :) The stausbar filter menu and info is replaced by a zoombar with two additional buttons - 'Fit' and '100%', which either fits the picture to the window or show it in it's original size. If the picture is zoomed more than the window can fit, a small translucent rectangle will appear on the right side showing your current position, which you can change right from there by simply dragging the inner rectangle, the image moves simultaneously. Images can be switched by spacebar to the next and backspace to the previous image. These and others can be configured from the 'Settings' main menu, under the 'Configure Shortcuts...' menu.
Double-clicking the image in the 'View mode' will switch it to fullscreen viewing. If you move mouse to the top screen edge, a small toolbar will slide down. In this toolbar you few buttons like starting a slideshow, switching to the next or previous image, rotating the image (very useful when you're presenting pictures and you find some that needs rotating; no need to exit the fullscreen slideshow, just click the button and keep watching), the wrench button hides the slideshow and the topbar setting - timeout, theme and height of the topbar and one thing I particularly like is the possibility to set random order in the slideshow, you can just load some folder with tons of images, hit fullscreen, check the 'Random' setting and then leave it whole day just nicely fading some great pictures. The other half of the fullscreen topbar is thumbnails strip where you can also make images selection, either by the classic old ctrl+click or by using the image overlay buttons for selection without keyboard.
Very similar thumbnails bar is also present in the 'View mode'. This greatly combines viewing the image and displaying the contents of the current folder. When you make a selection of more than one image, either from the 'Browse view' or the thumbnail bars, all those images in that selection are then displayed in 'View' and 'Fullscreen' modes. However one can't apply operations on this whole selected group, but I imagine it wouldn't be that hard to implement. You can still use batch processing though, see below..
The main toolbar has things already covered - buttons to switch between views, buttons to move to the next or the previous image, buttons to rotate the image left or right and then a 'Share' button. Thanks to kipi-plugins, one can export images right from Gwenview directly to 17 services, including email, Facebook, Picasa or the famous Czech rajce.net. As in every KDE application, the toolbar is fully customizable, you can add or remove buttons or change how they are displayed.
Thanks to the kipi-plugins you can do all sorts of things right from Gwenview - import images from several services (Facebook, Picasa or scanner), convert to black & white, print, create a panorama and more. All these can be found in the 'Plugins' main menu (provided you have correctly installed kipi-plugins). If you miss a feature or export/import service, you can very simply add it by writing a kipi-plugin. This plugin would then be used by every app that enables them, like digiKam or KSnapshot.
Among the plugins you will also find set of features for batch processing. These enables you to convert images between formats, do a batch renaming, add border and effects or recompress and resize the images.
Gwenview is truly a great application. Just go and explore it (hint: open Help->Gwenview Handbook and see the chapter Tips for some tips). I simply enjoy the times I open it for viewing my images. If you have ideas on how to improve it even more, you can either file a wish on bugs.kde.org or add your idea to KDE Brainstorm at forums.kde.org. And if you think the author, Aurélien Gâteau, deserves a 'Thank you', don't hesitate to express it! Appreciation for good work always makes the people spending their free time on it happy ;)
(and before you ask, I use standard Oxygen with slimmed scrollbars and my own color scheme based on one of Bespin's color schemes ;)