GIMP FAQ – Using GIMP

 

  1. How can I draw a straight line with GIMP?
  2. How can I draw a circle with GIMP?
  3. How can I create an outline around text?
  4. What are layers?
  5. How do I save a selected sub-image to a file?
  6. How do I save an image with an alpha channel?
  7. How do I merge an image from a file to the current image?
  8. How do I get small fonts to look as nice as large ones?
  9. How do I bind keys to menus for shortcuts?
  10. How do I select a layer “sitting” under the mouse cursor? I have more than 400 layers in my image and I cannot remember each layers name.
  11. I hate switching between windows in GIMP. Isn’t there an easier way?
  12. Is there a macro recording interface?
  13. How do I configure my X server to do global gamma correction?
  14. How do I fill with transparent?
  15. How do I draw in a different color?
  16. How can I export my path to SVG?
  17. How do I do something really simple like blur?
  18. I’ve tried to use GIMP but I just don’t get it – what am I missing (and I know nothing about images so dont start about alpha channels and layers, etc).
  19. How can I paint easily an (OutLined) rectangle using GIMP ?.
  20. How do I edit properties of existing guides? How do I move existing guides?
  21. How do I select the layer currently shown under the mouse cursor? Is there a shortcut?
  22. How can you wrap text using the Font tool? There are alignment buttons (including justified) but they have little effect since I can’t work out how to make the text wrap.
  23. Why do I have to make my rectangular selection exactly right the first time? Why can’t I move and resize a rectangular selection using handles?
  24. I recently saw a project that specified files were to be saved in Photoshop “Save for Web -> High (15K to 30K Optimized)” format. Is there an equivalent in GIMP?
  25. How do I get GIMP to be by default image tool i.e. I installed another program & it is now associated to auto-opening them.

Using GIMP

How can I draw a straight line with GIMP?

See Drawing a Straight Line in the GIMP user manual.

How can I draw a circle with GIMP?

The easiest way is to create a new selection with Ellipse Select tool and stroke it (Edit -> Stroke Selection…). We welcome patches that add tools to draw geometric primitives on canvas.

How can I create an outline around text?

Place some text somewhere. Then click “Create path from text” in the “Text tool option” window. Then use “Edit” -> “Stroke path” and select the appropriate options in the following dialog. Please also see the Paths section in the user manual.

What are layers?

The best analogy is to the way cartoons used to be animated. Each component of a scene would be painted on a transparent film, and then each film would be stacked or layered over the other to produce the complete composition. In this way, you could easily animate a person walking because his legs could be animated independantly of his body, for example. Similarly, complex images can be broken down to layers within GIMP and each layer can be processed independentlly of every other. See the Layers section in the manual for more information.

How do I save a selected sub-image to a file?

Use “Edit->Paste As->New Image” menu command or press Ctrl-Shift-V key combination, then save newly created image.

The script-fu-selection-to image can also be used to cut a selection out of an image and create a new image with it.

How do I save an image with an alpha channel?

Before saving the image, select “Layers->Flatten Image”. It would be more intuitive if it was called something like “Remove Alpha”…but that’s generally not its primary function. It just happens to remove alpha.

How do I merge an image from a file to the current image?

Use “File->Open As Layers” menu command or just drag the file to a window and drop it there. The file will be added as a new layer on top of the layers stack.

How do I get small fonts to look as nice as large ones?

Make sure you have “Hinting” and “Antialiasing” options enabled in Text tool options dialog.

How do I bind keys to menus for shortcuts?

Make sure that “Use dynamic keyboard shortcuts” option in “Interface” tab of Preferences dialog is enabled, then go to the menu selection you are interested in. Keeping it selected (hold the mouse’s menu selection down if necessary), press the key sequence you wish to assign to the menu. It will appear on the right of the menu. The new binding will be saved and used in future GIMP sessions. You can also use “Keyboard Shortcuts” dialog (“Edit->Keyboard Shortcuts”) to assign keys to menus and functions.

How do I select a layer “sitting” under the mouse cursor? I have more than 400 layers in my image and I cannot remember each layers name.

Please turn on “move-tool-changes-active” in the preferences dialog. Then (after you did a restart of GIMP) hold down the shift-key while you drag or click a layer in the image. The layer will now be selected (active).

I hate switching between windows in GIMP. Isn’t there an easier way?

You are probably using Windows or some GNU/Linux window manager that does not support the “Utility window” hint. Right now you can use list of currently opened images in “Windows” menu.

If you are using GNU/Linux or some free UNIX-like system and not willing to use GNOME and Metacity (its window manager) which does support “Utility window” hint, alternatively you can use a window manager like Fluxbox where you can apply this “always on top” property to the toolbox and layers dialogue. Window managers like Fluxbox also allow you to focus, or even raise, a window whenever you move the mouse over it (usually you have to click on a window before it will focus). Fluxbox allows you to stack windows together and the tab between them, much like Firefox can tab between web pages. Combined with focus-follows-mouse, this may increase one’s workflow considerably. Fluxbox also requires very few resources meaning more memory for your images. Finally, don’t forget about keyboard shortcuts and modifiers. Learning these means you rarely have to visit the toolbox.

In the mean time, during 2.7.x development cycle we will do our best to switch to tabbed user interface with docked palettes.

Is there a macro recording interface?

Not at this time. With GIMP based on GEGL, so that all changes are non-destructive, it will be much easier to implement this feature by just remembering all nodes in given range and reapplying them to other images. This is something that can be part of a future release of GIMP like 3.0.

How do I configure my X server to do global gamma correction?

Some servers have no facility for this; you may be able to adjust your monitor to correct somewhat. Later versions of XFree86 allow these server options:

  • -gamma f set gamma value (0.1 < f < 10.0) Default: 1.0 -rgamma f set gamma value for red phase -ggamma f set gamma value for green phase -bgamma f set gamma value for blue phase

How do I fill with transparent?

If your image doesn’t have an alpha channel, add one with Layers->Add Alpha Channel. Select the area you want to clear (if not the whole image). To change everything of a particular color transparent, pick Select->By Color… and click on the color in the image you want to replace. Then select Edit->Clear. That’s it.

Any dithering, blurring, or related effects against the color you replace will be against the original color. This usually requires you to do some form of cleanup of the edge pixels. In cases likely to result in this, change the color to transparent as early as reasonably possible to preclude extra “cleanup” work.

How do I draw in a different color?

At the bottom of the toolbar there is a box with two smaller boxes and an arrow. The uppermost box displays the current foreground color; the lowermost box displays the current background color. You can single-click on the arrow to switch these two. You can also double-click on either of the color boxes (or single-click if that box is already selected) to pop up a color selection tool, with which you can elect any color you like for that box. That color then becomes the new foreground or background color. Subsequent drawing operations (including text and color fill) will now use these colors.

How can I export my path to SVG?

Open the dialog “paths”, right click the path you want to export, click “Export path…” and save it as “yourpath.svg”.

How do I do something really simple like blur?

There are two methods, one for the current selection or current layer and one tool to blur using mouse. The tool looks like a waterdrop. Click it (or use shortcut V) and hold down the left mouse button while moving the mouse cursor over the desired area. Method two uses the blur filter (Filters -> Blur filters -> Blur) and as said it applies to the current selection and/or layer.

I’ve tried to use GIMP but I just don’t get it – what am I missing (and I know nothing about images so dont start about alpha channels and layers, etc).

There is plenty of documentation. See http://docs.gimp.org/en/ If you need a complete course about photoediting, image manipulation etc. then a book would be the best to start with.

Example books:

“Beginning GIMP: From Novice to Professional” – Akkana Peck

“GIMP Pocket Reference” – Sven Neumann

“Gimp: The Official Handbook” – Karin Kylander, Olof S. Kylander

“GIMP Visual Quickstart Guide” – Phyllis Davis

“Guerrilla Guide to Great Graphics With the Gimp” – David D. Busch

and many many more! Check your local books-dealer!

How can I paint easily an (OutLined) rectangle using GIMP?

Use “Rectangle Select” tool (see http://docs.gimp.org/en/gimp-tools-selection.html) for making a selection in the form of a rectangle. Then use “Edit” -> “Stroke Selection” (see http://docs.gimp.org/en/gimp-selection-stroke.html). The “Rectangle Select” tool has the shortcut “R”.

How do I edit properties of existing guides? How do I move existing guides?

Use the Move tool (Toolbox) or press M, then click and drag a guide. If the dragging moves the layer you have to switch modes (hold the shift-key while dragging or click “Pick a layer or guide” in the Move Tool options window). See “Grids and Guides” section of the online manual at http://docs.gimp.org/

How do I select the layer currently shown under the mouse cursor? Is there a shortcut?

There isn’t a context menu or shortcut. But you can move visible layers (not overlapped by another one) with the move tool (and holding down the shift key). Use the Move tool (Toolbox) or press M, then click and move a layer. If the dragging moves the currently selected layer you have to switch modes (hold the shift-key while dragging or click “Pick a layer or guide” in the Move Tool options window). This doesn’t select the layer, it only moves it. See “Move tool” section of the online manual at http://docs.gimp.org/

How can you wrap text using the Font tool? There are alignment buttons (including justified) but they have little effect since I can’t work out how to make the text wrap.

Text cannot be wrapped automatically. But when you type some text in the text-editing dialog you can just hit enter for a new line. In that case the alignment buttons would apply.

Why do I have to make my rectangular selection exactly right the first time? Why can’t I move and resize a rectangular selection using handles?

You can, at least in version 2.3.10 of GIMP. (notice the small arrows at each edge of the rectangular selection.)

I recently saw a project that specified files were to be saved in Photoshop “Save for Web -> High (15K to 30K Optimized)” format. Is there an equivalent in GIMP?

Yes, there is a plug-in for GIMP which is called “Save for Web” and created by Aurimas Juška as a Google Summer of Code SOC project. It allows visual adjustment of various image parameters such as quality, number of colors, dimensions, etc to reach optimal file size.”, see http://registry.gimp.org/node/33.

How do I get GIMP to be by default image tool i.e. I installed another program & it is now associated to auto-opening them.

It depends on what operating system you are using.

  • Windows: Right-click on an image in explorer and select “Open with…” in the context menu. Select GIMP and mark “Use this program as standard for openening this filetype”. Now the filetype of that image should be properly associated with GIMP.
  • GNU/Linux (KDE): Right-click on an image in konqueror, select “Open with…” -> “Other” in the context menu, select GIMP and check the box “Associate filetype with this program”.
  • For all other operating systems check the manual of the os.