Go to TopThe GIMP Interface

When the customised version of GIMP Portable is first launched after copying the software onto students' flash drives, the program opens two windows the Main Window and the Toolbox. These are described below.

Having loaded the image to be edited, the general process is a cycle of selecting a tool, checking and, if necessary, adjusting its options, and then applying the tool to the image.

In most cases the tool to be used can be selected from those displayed in the top half of the Toolbox window, though occasionally the menus on the main window need to be used.

Go to TopThe Main Window

The Main GIMP window

The Main GIMP window

The main window is conventional, containing the program's name on the title bar and a menu under it. Until an image is loaded the window's background shows "Wilber's eyes".Wilber is the GIMP mascot!

Although images can be loaded conventionally using the Open Image dialogue, it is often quicker to drag an image file from a "My Pictures", or similar window showing a set of thumbnails, and drop it onto Wilber's eyes.

Once an image is loaded the window adds a number of additional features. It then becomes referred to as the Image Window, described below

Go to TopThe Toolbox

A freshly installed copy of the GIMP

A freshly installed copy of the GIMP

In many image editing programs the second window, known as the Toolbox, would be integrated with the main window and appear as a pair of tool bars under the menu bar or down one side of the window.

The various buttons in the top half of the window, echo those of a conventional tool bar, engage the editing tool to be used for the next task, The default tool is the paintbrush and this button is shown depressed to indicate it is active,

The bottom half of the Toolbox, in this customised version, shows a number of tabs. The first of these shows a dialogue to control the options for the currently selected tool. (The other tabs are normally displayed in a separate window, known as a Dock and described in Customising the GIMP.)

On applying some tools a further dialogue window will appear on the screen, and the OK button on that window will need to be clicked to apply the required change to the image. In other cases the edit can be achieved with a sequence of mouse actions. There is no simple rule to know which of these approaches will apply and these need to be learnt through experience with the program.

A number of the tools involve applying colour. The currently selected colours to be used by any of these tools are indicated by the Colour Control. This consists of the two overlapping rectangles under the tool buttons. The top left block (initially Black) controls the foreground colour and the partially hidden, lower right, block (initially White) controls the background colour. Which colour is applied depends on the tool selected. (For example the Paintbrush will apply foreground colour whereas the Eraser tools removes the current colour replacing it with the defined Background colour.)

Clicking on either of the coloured squares opens a Colour picker dialogue so the colours may be changed. Clicking the double-headed arrow to the top right, toggles the foreground and background colours. Clicking the black and white squares to the lower left, restores the default black foreground and white background colours.

Notes on the Toolbox Window

The GIMP's Toolbox is a special "Utility window". Unless the GIMP Preference settings are adjusted, it always floats over the GIMP's Main and Image windows. Because of this behaviour it can be easiest to adjust the size and position of the Toolbox and Image windows so they do not obscure each other. Alternatively, use this tip:

TIP: Hit the TAB key to hide the Toolbox (and any other visible utility windows).
To reopen a hidden Toolbox, make the Image window active and hit the TAB key again.

WARNING: The Toolbox Close button (on its title bar) not only closes the Toolbox, it also closes the entire program! (Though it will prompt you to save a changed image!). See the tip above to hide the Toolbox.

Go to TopOpening the Image File

To edit an photograph file, you first need to open it. This is often most easily done by dragging the images file and dropping it on "Wilber's Eyes" on either the Main Window or the Toolbox. The Open Image dialogue is unconventional and needs some explanation.

On The Main or Image Window, open the FILE menu and select OPEN (Keyboard: CTRL-O). The "Opens Image" dialogue appears...

The GIMP Open image dialogue

The GIMP Open image dialogue

This offers all the features of the standard Open dialogue and more!

Across the top are a selection of buttons. The first, extends the dialogue by adding a further line into which you can type part of a folder or file name and it will provide a filtered list of names that match the characters typed so far. This may be useful in folders with many files. The next group allow show the path of the current folder. You can navigate along this path by clicking on any of the buttons. To the right the "Create Folder" button will open a dialogue that places a new folder at the current level in the folder structure.

Beneath are the three main panels. The Places panel is divided into three parts. Clicking the single item in the top one will reveal a list of recently edited files in the middle Name panel. The mid part lists your main directories and your storage devices; you cannot modify this list. The bottom part lists your bookmarks; you can add or remove bookmarks. To add a bookmark, select a folder in the middle panel and click on the Add button at the bottom of the Places panel. You can also use the Add to bookmarks command in the context menu, which you get by right-clicking. You can delete a bookmark by selecting it and clicking on the Remove button.

The central Names panel displays a list of the contents of the current folder. Change your current folder by double-clicking on a folder in this panel. Select a file with a single left click. You can then open the file you have selected by clicking on the Open button. Note that a double-click opens the file directly; if you have selected a file different from the current one, a message warns you before GIMP overwrites your work.

On the right the Preview panel will display most images. File size, resolution and the image's composition are displayed below the image.

The function of the other controls on the dialogue is either obvious or of little significance to someone editing images from their digital camera.

Go to TopThe Image Window

The GIMP's Image Window

The GIMP's Image Window

As a file opens the window re-sizes itself automatically to accommodate the entire image, typically reducing it to a fraction of its true size, indicated by a percentage figure on the window's status line. Meanwhile the Title bar indicates not only the file name but its size and other technical information.

The window features four Special Buttons. At the top at either end of the horizontal ruler and at the bottom at either end of the horizontal scroll bar. These are described in the following section.

The Status Line also provides two controls that can be used affect the window's display, as well as the more conventional reports on the window's display. These are described below.

Window Buttons:

Menu Button Allow Floating Menus:
Opens a menu that can be detached from the button and made to float anywhere on the screen. See Floating Menus, below
Zoom to Window Button Zoom to Window:
Toggles how the image behaves when the window is re-sized.
Depressed: The image re-sizes as the window is resized.
Raised: The image remains the same size and the window reveals more or less of the image.
Quick Mask Button Quick Mask:
Toggles the Selection Mask. Most useful for seeing the effect of a feathered selection.
Navigate Image Button Navigate Image:
Reveals a thumbnail of the whole image. Drag over the thumbnail to highlight the portion of the image to appear in the window.

Status Line

Shows Pixels (px) by default, but if preparing an image for printing rather than display on a computer or TV screen, it may be preferable to use this list to change the units used on the window's rulers.
Zoom Control
Enter a value or pick one from the drop-down list shown along side the percentage figure to zoom the image in or out. (The scroll bars or the Navigation button can be used to display the desired portion of the complete image when heavily zoomed.)
Status Area
Most of the time, by default, it shows which part of the image is currently active, and the amount of system memory that the image is consuming. When you perform time-consuming operations, the status area changes temporarily to show what operation is being performed, and its state of progress.

NOTE: The amount of memory consumed by the image is quite different from the image file size. For example, the image shown above, at 4.5Mb, was loaded from a 63Kb JPG file. There are two reasons for this. First, the image is reconstituted from the compressed .JPG file and then The GIMP keeps a second copy of the image in memory (to be used by the Undo command).

Floating Menus

GIMP activating a floating menu

GIMP activating a floating menu

Menus accessed from the Image Window's top left button have a dotted line above the first option. Clicking the dotted line will force a copy of the menu to appear as a conventional independent window able to float around the entire screen.

Once floating, a menu window can be closed using the convention title bar button or by clicking the dotted line at the top of the menu, now with a left pointing arrowhead.

Go to Top Page updated: 22 February 2010