The gThumb image viewer is a powerful tool for viewing, and organising graphic image files. To start this application perform:
Main Menu --> Graphics --> gThumb Image Viewer
Click to view screen shot Fig 6.9 gThumb Image Viewer.
On start up gThumb by default will check your home directory for any image files and if detected the gallery panel will automatically generate thumbnails of the images.
View
Once the thumbnails of the images in a folder have been generated by gThumb the simplest way to view an image is to double-click on the thumbnail and it will be displayed in full. You can also navigate to the next/previous image as well as go to full-screen viewing. The Zoom function can be used to zoom in or out of the image currently being displayed. Click on the Folders button at the top of the screen to go back to the thumbnail view. A preview of the image will be displayed in the preview area if you just select the thumbnail.
One useful feature of gThumb is the slide show. Clicking on this button will start a full screen slide show of the images in the folder.
Image Manipulation
You can also manipulate the images under gThumb. Supported functions include rotation, flipping, resizing, colour balancing, brightness control. To access these functions select Image from the menu bar at the top.Libraries and Catalogs
gThumb allows you to organize your images in libraries and catalogs. Catalogs are logical views of a group of images and are an alternative to physical organization in folders. A catalog enables you to group together images with a similar theme or category even though physically the image files may be in the same or different folders. For an even higher level of organization you can create libraries and then place catalogs under a library.Libraries and catalogs can be created and manipulated under the catalog view mode. Double-click on the Catalog icon to enter this mode. On entering this mode the folder list panel (at the top left), becomes the library/catalog list panel. From this panel you can access and navigate your catalogs and libraries.
To create a new library, select
File --> New Library
and enter the name of the library. The created library will be displayed in the catalog list panel.
To create a new catalog select
File --> New Catalog
and enter the name of the new catalog. The created catalog will be displayed in the catalog list panel.
To organize a catalog under a library, you can either create the new catalog directly under the library or create the catalog first on its own and then move it under the library in question. The library/catalog list panel is used for navigating the library list.
To organize images into a catalog, go to the folders view mode (by double-clicking on the Folder icon), select the image(s) you want and then select
Edit --> Add to Catalog
The Choose a Catalog screen will pop up, choose a catalog from the list. If the catalog you want is under a library select the library first and then the catalog.
Convert Format
The Convert function of gThumb allows you to convert your image files from one format to another. Supported formats are:
- Portable Network Graphics (PNG)
- Tag Image File Format (TIFF)
- TARGA format (TGA)
To use the Convert function, select an image first and then from the top menu bar, select,
Tools --> Convert Format
Help
gThumb has many other useful features. The online help guide should be consulted for more details on how to use gThumb.
Exercises
Use gThumb for the following:1. View the images in the following folder: usr/share/backgrounds/images
2. View a slide show of the images in the folder above.
3. Copy one of the images from the above folder into your home directory and scale it down to 25% of its original size and save it.
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You are reading
Tutorial: Multimedia and Graphics Access
1. Multimedia Access and Players
2. The Volume Control Applet
3. Playing Audio CDs
4. Playing Digital Audio Files
5. Playing VCD and DVD
6. Graphic Images Access
7. Using File Manager to Access Image Files
8. gThumb Image Viewer
