Revision 12 as of 2015-04-02 04:22:19

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gThumb Image Organizer Basics

  • The JPEG file of a photograph contains more information than just what is necessary to show the picture. It also contains a lot of text information called EXIF (Exchangeable Image File Format) data. Most of this is technical photographic information set automatically by the camera and includes the make and model of the camera, the f settings, the shutter speed, and so on. It is of little or no use in organizing and finding pictures. But there are a few fields, left blank by the camera, which can be used to label and index the picture. These fields can then be searched to find pictures of a particular subject or taken in a particular place or at a particular time. gThumb is a program produced by the Free Software Foundation, Inc. to edit this EXIF information, to enter into it a title, a date, and location of a picture as well as various tags with names made up by the user. It can also search a directory for pictures with a desired word or words in the title, a desired date, location, or tag. It also has some very limited capability for image editing, such as rotating or converting from one file format to another, but that is not its strong point.

    Its strong point, in fact, is the simplicity with which it edits the EXIF data, also called metadata or comment data, and then searches for images with metadata matching search criteria specified by the user. It is available free for Linux but not at all for Windows or Mac. It is easily gotten from the Ubuntu repository. On Linux, it competes with Shotwell, F-spot, and recently Corel Aftershot. In the world of free software for Windows, IfranView and Google's Picasa also work with with the EXIF data, and data that has been entered by any one of them can be used by all of the others; it is embedded in the .jpg file and moves with that file wherever it may go and is available under any operating system to any program that works with the EXIF data. Picasa is also available for Mac and has a convenient way of “geotaging” a picture with longitude and latitude by working with GoogleEarth or Google maps. These other programs offer more than gThumb for image improvement, but (aside from geotaging) for ease of editing and searching the EXIF data, gThumb heads the list. As of April 2015, the help obtained by clicking Help on the main menue does not match the program. The following information matches the program installed from the Ubuntu repository in late March 2015. The "About" page that it is version 3.2.7.

Editing EXIF data

  • To get started with with gThumb, put a number of .jpg files that you want to organize into a directory (also called a folder). Open gThumb and in the opening window navigate to your directory. Thumbnails should soon fill the gThumb window. Click on the thumbnail of a file whose EXIF you want to edit. Then in gThumb's main menu across the top, Click Edit and then Comment. gThumb also has a tool below the main menu; equivalently, you can click “Comment” in it. (“Comment” apparently is intended to mean the part of the EXIF data that you are likely to want to change.) The window shown on the right appears, without, of course, the data that has been entered about the Royal Palace at Knossos.

attachment:gThumbOne.png

  • Fill in the Title, Place and Date fields as appropriate. You will later be able to search for what is in these fields and to show them below the image in the browser view. We will return to the Tags field. Information can also be recorded in the large Description box. This information can be searched but cannot be displayed below the image in the browser view. In the previous picture, you perhaps noticed that there was a tab with the label Other. Clicking it brings up the window on the right. It has places for location information which will not be confused with geotags. However, it does not seem to be possible to search for information on this tab, so it cannot be used for indexing, at least not in gThumb.

attachment:gThumbTwo.png

  • We return to the General tab and the Tags box. Tags are one-word labels we can give to pictures. They can then be used to search and locate pictures with a particular tag. Note the drop-arrow to the right of the Tab field. Click it, and you will see a rather strange initial list of possible tags. Perhaps someone was using them, but you will probably want to delete most of them by right-clicking on them and choosing “Delete”. Then by clicking in the box on the top, you can type in new tags to your liking. As you do so, your tag is added to the list of available tags. Next time you want it, you just have to click on it.

Showing the Metadata with the Thumbnails

  • gThumb's browser window showing the thumbnails does not automatically show any of the metadata that goes with the images, not even the filename of the image. That can be remedied to show selected metadata that was on the General tab when editing the EXIF data. To do so, click Edit on the gThumb main menu and then Preferences and then the Browser tab, so Edit > Preferences > Browser. A window comes up as shown on the left below. A click in the box of an item moves it into the top pane of the window, where it appears with its box checked. Items in this top pane can be dragged up or down; they will appear in the browser in the order in which they appear in this top pane.

attachment:gThumbTwo.png

Finding the Pictures You Want

  • Once again, start from Edit and then pick Find. A window like that on the right The one shown, however, has been expanded by the clicking the big green + control on the right to add a second criterion and the “Match” control has been set to show images which match and of the criteria specified below. The result of the search – which took several seconds in a directory with about 1000 jpg's – was to show the two images which matched one or the other of the rules, as shown below.