# gThumb User Guide

## Introduction

gThumb is an image viewer and browser written for the GNOME environment. It lets you browse your hard disk, showing you thumbnails of image files. It also lets you view single files (including GIF animations), add comments to images, organize images in catalogs, print images, view slideshows, set your desktop background, and more.

To run gThumb, select its entry from the Graphics submenu of the Applications menu, or type `gthumb` on the command line. If you start gThumb from the command line you can specify a starting folder :

`gthumb `foldername``

or a list of files to view :

`gthumb `*.jpg``

you can even do a combination of the two :

`gthumb `*.jpg folder1 folder2``

The above example will pop up three windows, one shows you the files with a `jpg` extension in the current folder, and the others two will show you respectively the content of `folder1` and `folder2`.

## Browsing folders

When you first launch gThumb the main window pops up, four areas give you information about the current folder :

1. The location bar, which contains the current folder name.

2. The folder list, which shows you the sub-folders contained in the current folder.

3. The image list, which shows you the images in the current folder.

4. The status bar, where you can read the total number of images contained in the current folder and their size; the number of the selected images and their size; some properties of the current image.

### The main window

The main window

If you want to change folder you have two options, clicking on the folder name in the folder list, or typing the folder name in the location entry. When using the location entry you can press Ctrl TAB to try to automatically complete the folder name, this simplify the typing of long names.

To go to a previously visited folder you can use the Go Back command or click on the Go menu that contains a list of the most recently visited ones. In this menu keeping the pointer on a folder name will display the full path of the folder in the statusbar.

Frequently used folders can be added to the bookmark list for rapid access. Just go the folder and press Ctrl D or use the command Bookmarks Add Bookmark. For removing or rearrange bookmarks in a different order use the Bookmarks Edit Bookmarks command.

To sort images in a different order use the Sort images submenu in the View menu, use View Refresh to reload the current folder, click on View Thumbnails to view or hide the thumbnails in the images list.

To move, copy and rename images, select the images and use the corresponding command in the Edit menu.

To open an image, or a series of images, with an external program select the image and use the File Open images with command.

## Keyboard shortcuts to navigate your folders

Shortcut | Description
N , Space or Page Down | View next image.
B , P , Backspace , Page Up | View previous image.
Home | View first image.
End | View last image.
Alt Home | Go to your Home folder.
Alt Left | Go to the previously visited folder.
Alt Up | Go to up one level.
Ctrl D | Add bookmark.
Return | View/Hide the browser.
Q | View/Hide the image preview.
T | View/Hide thumbnails.
F2 | Rename current image
O | Open selected files with an application
Delete | Delete seleceted files

Other options for the browser can be found in the Browser tag of the Preferences dialog.

## Viewing images

In order to view an image just click on its thumbnail and the image will be visualized in the viewer pane. If the image doesn't fit the viewer pane you can give more space to the viewer hiding the browser, this can be accoplished pressing the Return key, pressing it again the browser will be re-displayed. Another way of viewing a big image is to view it in full screen mode, type V to activate/disactivate the full screen mode.

Mouse operations :

Holding down the left button and moving the mouse | move the image.
Left-click | Show next image.
Middle-click | Show previous image.
Right-click | Pop up the image menu.

Another way of moving the image is by the navigation button : located in the right bottom corner of the viewer window when the images does not fit in the window. Clicking and holding this button will show you a preview of the image. Moving the mouse you will move the image to the desired position.

### Altering images

There are a set of commands, located in the Image menu, that let you modify the current image.

Rotate Right | Rotate the image 90 degrees clockwise.
Rotate Left | Rotate the image 90 degrees counter-clockwise.
Flip | Create a mirror image by reflecting the image scanlines in the vertical direction.
Mirror | Create a mirror image by reflecting the image scanlines in the horizontal direction (as in a mirror).
Resize | Change image size performing a zoom in or out.
Color Balance | Change color balancement.
Hue-Saturation | Change the image hue, lightness and saturation level.
Brightness-Contrast | Change image brightness and contrast.
Desaturate | View the image in black and white.
Negative | View the image negative.
Posterize | Reduce the number of colors.
Equalize Histogram | Enhance the image equalizing its histogram.
Adjust Color Levels | Enhance the image adjusting color levels.

#### WARNING

Please note that this modifications do not change the image file, and if you want to view the original image just click on its thumbnail again or use the File Revert command.

To save the modified image use the File Save As command. Images can be saved in JPEG, PNG, TGA, TIFF formats. Each image format have some option that can be changed with a dialog that pops up after having entered the image filename. All the dialogs remember the last specified options.

## Some keyboard shortcuts

Shortcut | Description
V | Full screen
+ , = | Zoom in
- | Zoom out
1 , Z | Actual size
X | Zoom to fit
F | Flip the image
M | Mirror the image
R , ] | Rotate the image clockwise
[ | Rotate the image counter-clockwise
G | Start/Stop the current animation
J | View the next frame of the current animation

## Printing images

Click on the image you want to print, then select the File Print image command.

The Print setup dialog lets you

- Choose the paper format and orientation,

- Choose the printer to use,

- Choose the size of the image,

- Move the image clicking on it with the left mouse button and dragging the image where you want to put it.

- Recentre the image on the page use the Center on Page button.

When you are ready to print press the Print button.

## Adding comments to images

In order to add a comment to an image select the image and use the Edit Edit comment command or type C.

Comments are structured in various parts :

- Comment: a free text describing the picture.

- Place: the place the picture represents.

- Date: the date the picture was taken.

### The "Edit Comment" dialog

The Edit Comment dialog

You can even add a comment to multiple images, in this case the comment dialog will fill in the fields that are the same for all images leaving all other fields empty. When adding a comment to multiple images you can active the Save only changed fields option (which is active by default) which let you change one or more fields of the comment of many images leaving all other fields unchanged.

Image comments are displayed in the image list in italic text above the image filename. If the comment is too long the simbol "[..]" is appended to the displayed part of the comment to signal you that the comment is not entirely visible, to view the whole comment use the image properties dialog that can be displayed using the File Properties command or pressing I.

### An image comment

An image comment

To delete a comment use the command : Edit Delete comment.

Comments are not embedded in image files they are saved separately, this means that if you move the images or the folders images are in with other programs you will lose the comments. Comments are saved in the folder `$(HOME)/.gnome2/gthumb/comments`.

## Organizing images in catalogs

Catalogs lets you organize images without moving them from a folder to another, think of them as "playlists" for images. The following is the list of operations you can perform with a catalog :

- Viewing the list of catalogs : Press Alt 2 or select the View Show/Hide Catalogs command.

- Adding images to a catalog : Select the images you want to add to a catalog and use the Edit Add to Catalog command to select or create a catalog.

- Deleting images from a catalog : Select the images you want to delete then use the Edit Delete from Catalog command.

- Renaming, Deleting or Moving catalogs : Select the catalog and use the corrisponding command in the File menu, or use the context menu pressing the right mouse button on the name of the catalog in the catalog list.

If you want to go to the folder that contains an image, select the image and use the Go Go to the image folder command or press Alt End.

Catalogs are not updated when you move images, if you want a more flexible catalog you can use the searches described in find, searches are catalogs with search criteria attached, after moving images you can redo the search to get the catalog updated.

Catalogs are saved in the folder `$(HOME)/.gnome2/gthumb/collections`.

## Finding Images

The Find Images tool lets you find images on you hard disk and save the result as a catalog. To use this tool select the Find... item from the Edit menu.

### The "Find" dialog

The Find dialog

When the dialog pops up, you can specify a file name or a pattern in the File name entry, for example :

- `foo.jpg`: will search for files named foo.jpg

- `*.png`: will search for files with the png extension.

- `*.gif; *.jpg`: will search for files with the gif or jpg extension.

  with an image editor

Other search rules:

- Start at: The folder the search will start from.

- Include sub-folder: Whether to search even in the sub folders.

- Comment: A list of phrases the comment of the image must contain, for example:

  - `paolo`: will search for images that have "paolo" in the comment.

  - `my birthday`: will search for images that have "my birthday" in the comment.

  - `holiday ; rome`: will search for images that have "holiday" OR "rome" in the comment.

  - `holiday in rome ; my birthday`: will search for images that have "holiday in rome" OR "my birthday" in the comment.

- Place: A list of phrases the place field of the comment must contain, for example:

  - `rome`: will search for images that have "rome" in the place field.

  - `paris ; rome ; london`: will search for images that have "paris" OR "rome" OR "london" in the place field.

- Date: The criteria the date field of the comment must respect:

  - any: the date field is ignored.

  - before, equal to, after: the date must be less recent, equal to or more recent than the date specified.

- Categories: The list of categories an images must belong to. Categories can be added to images using the Edit Categories command or pressing K. Examples:

  - `family`: images must have "family" has one of their keywords.

  - `me, family`: images must have "family" and/or "me" in the keywords list.

  You can choose to search for images that belongs to all the specified categories or at least to one of them, checking the corresponding option.

If you use more than one criteria images must respect all of them.

The search is always case insensitive.

### The "Search Progress" dialog

The Search Progress dialog

Pressing the Search button the search will start. Once the search has finished you will see the list of files that matches your search, if you want to see these files press the View button, if you want to make another search press the New Search button.

If you choose to view the files, a catalog named Search Results will be created and visualized automatically. A catalog created in this way has a special icon, a magnifier, this is because on this type of catalog you can perform two more operations : Edit Search and Redo Search .

### The "Search Result" catalog

The "Search Result" catalog

These operations can be selected from the File Search menu, or from the menu that pops up when pressing the right mouse button on the catalog name.

The Edit Search command lets you re-edit the search rules, while Redo Search lets you restart the search, at the end of the search you can decide whether to save the result in the catalog or not.

## Slide Show

You can start a slide show of the images in the current folder by pressing S or selecting the View Slide Show menu item. To stop the Slideshow press S again.

Switching on/off the full screen mode does not stop the slide show. If the Switch to full screen option is on then the slide show is started in fullscreen mode and exiting from the fullscreen mode stops the slide show.

The slideshow is interrupted when changing folder or re-loading the current one.

If you want to do a presentation with images you do not need this tool, instead you can simply set the fullscreen mode and press Space or Page Down to view the next image, and b or Page Up to view the previous image.

## Advanced Tools

### Wallpaper

If you want to set the selected image as desktop wallpaper select the menu Set Image as Wallpaper from the Tools menu. The menu contains four items each of which let you set the wallpaper in a different way:

- Centered -- The image will be centered on the screen.

- Tiled -- The image will be duplicated on the screen as tiles on the floor.

- Stretched -- The image will be scaled to fill the screen changing proportions if needed.

- Scaled -- The image will be scaled to fill the screen mantaining the aspect ratio.

If you want to restore the old wallpaper use the Tools Set Image as Wallpaper Restore item.

### Rotate JPEG

Usually if you want to rotate an image you have to open the image with an editor, rotate the image and save it. This works good for image formats such as PNG or GIF, but results in a loss of quality for JPEG images.

If you want to rotate JPEG images without losing image quality, select the images you want to rotate and use the Tools Rotate JPEG command.

If you check the Apply to all images option the rotation is applied to the currently displayed image as well as to all the remaining images you have selected, otherwise, once the rotation has been performed on the current image, the next image in the selection is displayed, and you can choose another type of rotation.

If the selection contains some non-JPEG images, they are simply ignored.

### Convert Format

With this tool you can change the format of images. To use it select the images you want to convert, and use the Tools Convert Format command.

The Convert Format dialog offers you the following options:

- Image type: this is the format you want to convert images into.

- Overwrite mode: a converted image has the same name of the original image except for the extension which is determined by the new format, an image with the new name can already exist in the destination folder, this option lets you decide what to do when such a case occurs. If use choose skip the new image won't be created; rename will ask you to specify a new name; ask will ask you whether to overwrite the old image or not and overwrite will overwrite the old image without asking.

- Remove original: lets you remove the original image. If an image is not converted because of an error it will not be removed.

### Rename Series

With this tool you can change a series of image filenames specifing a name template. In order to use it select the images you want to rename, and select the Tools Rename Series command.

The name template is simply a name that must be used for all of the images, furthermore you can use two special characters to make the new names different each other:

- # -- This symbol will be replaced with the value of a counter that increments itself by 1 passing from one image to another. If you specify this symbols in sequence you'll get leading zeros if the counter value has a lesser number of digits, for example ### will produce the sequence: 001, 002, 003, etc..

- * -- This symbol will be replaced with the image original name.

The list at the bottom of the dialog display how the filenames will be renamed.

If the renaming of an image can overwrite an already existing image you will be asked how to proceed, five options are available: overwrite the image, do not overwrite the image, always overwrite, never overwrite, specify a new name.

### Change Date

If you want to change the last modified date of a series of images, select the images and use the Tools Change Date command.

### Index Image

An index image is an image that contains small previews of a series of images. If you want to create an index image select the images you want to insert in the index and then use the Tools Create Index Image command.

### Maintenance

To get access to maintenance operations select the Tools Maintenance menu item.

Backup Comments -- With this command you can create an archive of all the comments you have writed. After pressing the button you have to enter the archive name, for example: `comments.tgz`, or `comments.zip`. The archive is created using the application File Roller.

Restore Comments From a Backup File -- Use this command if you want to restore comments previously saved in an archive. After pressing the button you have to specify the archive where the comments are stored. The archive is extracted using the application File Roller.

Delete Old Comments -- If you use gThumb to delete or move images, comments are deleted and moved accordingly. Other applications do not handle image comments so it can happen that a comment exists but the relative image does not exist anymore. This command lets you delete such comments.

Delete ALL Comments -- This command will delete all the comments you have written.

Thumbnails are small versions of the images you have on your disk, they are used to speed up browsing. Thumbnails can use a lot of space, so in order to save disk space you may wish to delete all the thumbnails or only the thumbnails of no more existing images. The commands in the Thumbnails section let you do this.

## Preferences

To configure gThumb, open Preferences dialog by selecting Edit Preferences .

### Preferences Dialog

gThumb Preferences Dialog

This dialog contains four tabs described in detail below. At the bottom of the dialog window, you'll find the following buttons:

- Help: shows this manual.

- Close: closes the dialog.

Keep in mind that when you change an option it will automatically applied, this is why there is no Ok or Apply button.

### General Tab

This tab allows you to set the following options:

- Select the layout of gThumb main window, i.e. the positions of directory list window, the image (thumbnail) list window, and the main image viewer window.

- The toolbar style

- Directory to show on startup

- The history length, that is the maximal number of locations to show in Go menu. The default is 15.

### Browser Tab

In this tab, you can configure the following options:

Show thumbnails

- This option (which you can activate simply pressing T) controls whether gThumb should show thumbnails.

Show comments

- This option controls whether gThumb should show comments (including date and place) in the image list. By default, >humb; shows the comment as a caption under the thumbnail.

Show hidden files

- This option controls whether gThumb should show files with the names starting with dot (.). These files usually contain system information or applications settings. Since these files almost never contain user data, by default they are not shown by file manager and other applications. In most cases, you should leave this option unselected.

Thumbnails

- Here you can select the thumbnails size to your taste. By default, gThumb display thumbnails of size 95x95 pixels. If you like to view as much thumbnails as possible select a small thumbnail size, if you want to view detailed thumbnails select a big size. The other option lets you decide whether to save the thumbnails or not, saving thumbnails is highly recommended because this let you speed up browsing of folders you already visited, the drawback is that thumbnails occupy disk space so if your free space is limited you may prefer to disable this option but in most cases you should leave this option selected.

Other

- Here you can choose whether to change folder by doing a single or a double click on the folder name. The single click can be usefull if you are used to quickly browse your hard disk searching for images. The default behaviour is to follow the Nautilus file manager policy. Furthermore you can select whether gThumb should ask for confirmation before deleting an image or a catalog, and whether gThumb should determine image type by looking at the file extension or by looking at the file content. Determining file type from the content is more reliable (some applications may create files with extension not matching the actual file type) but slower. If you have a fast system, select Determine image type from content.

### Viewer Tab

This tab contains options for viewer window:

Zoom quality

- This controls the method used for showing rescaled image. Possible choices are high quality (slow on old machines or when viewing big images) and low quality (always fast).

After loading an image

- Controls initial zoom level to use for an image.

Transparency type

- Controls the background used for partly transparent images. By default the transparent part of the image is replaced the window background color,that is the none option.

Checks

- This option only has effect for partly transparent images and only if checked transparency type was selected. It controls the size and colors of checker board pattern used for the background.

### Slide Show Tab

This tab contains the options controlling slide show mode (which you can start by selecting Tools Slide Show or by using Ctrl S shortcut). The options include direction (forward/backwards), and delay between images. You can also specify whether the slide show should wrap around (i.e., after showing the last image start again form the beginning) and automatically switch to fullscreen mode.

## Keyboard Shortcuts

When the location entry is focused you can use Ctrl Tab to display a list of possible location completions.

## Keyboard shortcuts available when the location entry is NOT focused

Shortcut | Description
+ , = | Zoom in
- | Zoom out
1 , Z | Actual size
X | Zoom to fit
F | Flip image
R , ] | Rotate image clockwise
[ | Rotate image counter-clockwise
M | Mirror image
G | Start/Stop animation
J | Step animation
B , P , Backspace , Page Up | Show previous image
N , Space , Page Down | Show next image
Home | Show first image
End | Show last image
U | Go up one level
H | Go to the home folder
T | View/Hide thumbnails
Esc | Interrupt thumbnails creation
S | Start/Stop slideshow
V , F11 | Full screen mode
Return | View/Hide browser
Q | View/Hide image preview
F2 | Rename current image
O | Open selected files with an application
Delete | Delete seleceted files
C | Add a comment to selected images
K | Assign categories to selected images
I | View image properties (image name, size, EXIF data, etc.)

## Keyboard shortcuts available when the image is focused

Shortcut | Description
Arrows | Scroll the image
Shift Arrows | Scroll the image faster

## Keyboard shortcuts available when in fullscreen mode

Shortcut | Description
Escape , V , F11 , Q | Exit fullscreen mode
B , P , Backspace , Page Up | Show previous image
Space , N , Page Down | Show next image
Home | Show first image
End | Show last image
+ , = | Zoom in
- | Zoom out
Z , 1 | Actual size
X | Zoom to fit
S | Start/Stop slideshow
G | Start/Stop animation
J | Step animation
F | Flip image
R , ] | Rotate image clockwise
[ | Rotate image counter-clockwise
M | Mirror image
C | Edit current image comment
K | Assign categories to current image
I | View/Hide image comment
Delete | Delete current image

Look in the menus for other shortcuts.

## Developers

To find more information about gThumb, please visit the gThumb Web site.

Send all comments, suggestions, and bug reports to Paolo Bacchilega (paolo.bacch@tin.it).