GIMP Tutorial - How to make backgrounds transparent

This is a really useful technique. I use it all the time on photos of people to drop them on different backgrounds, often for wallpapers. For this example I've used the simple shape of a cube, but the technique is identical regardless of the complexity of the shape.

1. Select the Bezier tool. It looks like a pen - I've put a big blue arrow pointing to it. Make sure the polygonal box is checked.



2. Carefully draw nodes one by one around the object (which in this case is a pink cube). If you were trying to cut out a person, you would create many more nodes around them. The more you create, the better the cut-out, so take your time over this step.



3. When you reach the final node, you need to complete the path. Do this by pressing the Ctrl button on your keyboard as you click the first node, thus "joining the dots" and closing the path. Don't do anything else yet!!!!
Are you happy with your path? Remember, this is the stage where you can adjust your nodes.
When you're happy, you need to convert the path to a selection - just press Enter.
You should now see marching ants around your object/person. This means they are now a selection.

4. Invert the selection. You want to delete the background, not the object you just so carefully selected. Do this by going to Select-->Invert as shown below.



5. Delete the inverted selection. Your version of GIMP may do this differently. Some - just hit Delete. Others - try Ctrl+K. Or, right-click on the image and click Edit-->Cut, as shown below.



6. You now have an object on a transparent background. You can paste it on to any background you like.

AUTHOR Anon | 12:09 PM in GIMP, GIMP tutorial | |

30 Comments:

1. jonathan riley on July 24, 2007 12:15 AM

   That reminds me so much of toiling with this and other images using puny old microsoft paint back when you were busily revising for your finals :-O
   
   A few lessons I took from the painful exercise:
   
   1) It is almost useless to cut the image you want to paste without having regard to the background pixels you are going to paste onto. A really useful but tiring method was to merge two images together using rgb code from neighbouring pixels. You can plainly see where I did do this (and that it worked reasonably well) and where I didn't (where it looks more awkward and blocky). There must be a program for this sort of thing--doing it manually took a devil of a long time.
   
   2) Closely related to the above, a punctilious observation of small notches in an outline when carving out a zoomed in image (you do zoom in, I take it) can be a great mistake. A very great deal of time spent following the exact outline of an image makes one feel virtuous for having done all the hard work, but can lead to an image that looks woefully jagged. "Warts and all" is fine, but not when the warts have squarish (because pixellated) edges.
   
   3) Much better to work from a .png than a .jpg!

    
2. jonathan riley on July 24, 2007 12:19 AM

   Oh yes, and thanks for the tutorial, it will be a big help for sure :-)

    
3. CJ on July 24, 2007 8:14 AM

   Interesting points. Agreed.
   
   Regarding point 1 - if you look at the mode of your layers, you can change it. Different modes can give wonderful effects - and they have a "merge" one.
   
   Also - remember you can "smudge" the edge of your image, getting rid of that blocky pixel edge. Useful tool.

    
4. Evacita on December 13, 2007 11:14 AM

   Thank you so much for this tutorial. I've just started getting to know Gimp and I haven't thought that this was the easiest thing to use to do anything really. I've been wanting to try to cut things/people from pictures and put them somewhere else and I've never managed to find somewhere where they could explain it in simple terms for us mere mortals.... You have done just that so thank you so much for enlighting dummies like me! I can't wait to try the glowing thing around a character that you've precut! Thank you SO much!

    
5. CJ on December 13, 2007 3:52 PM

   Aww, you're very welcome. It's lovely to know when people find these useful.
   
   I'm completely self-taught. There's loads of tutorials for GIMP out there, but most of them assume you already know lots about the programme. For newbies, just being told to "open a layer and add a mask" is really confusing. So I'm glad that this step-by-step helped! :)

    
6. runescapehelpaz on January 5, 2008 1:54 PM

   this generaly is just NOT working! i do the noddy things and invert, i click cut and either nothing happens or my image dissapears!? PLEASE PLEAS E PLEASE PLEASE HELP!!

    
7. CJ on January 5, 2008 3:42 PM

   If you invert the SELECTION, it's not possible to delete the entire image.
   
   Therefore, make sure your selection is still active. If the "ants" aren't marching, you've lost your selection. There are lots of ways to restore this, but I can't go through them all. Try Ctrl+Z.
   
   If your selection IS still active, make sure you have inverted it correctly.
   
   Assuming that you DO have an active, inverted selection of the area around the object, and you say that "Cut" does nothing, try the other techniques that I listed for deleting the selection. My version of GIMP uses Ctrl+K. Older version apparently used to use Ctrl+Shift+K. Or try pressing Del.
   
   Not much else I can say. Unless your GIMP is buggy.

    
8. CJ on January 5, 2008 3:45 PM

   Oh, and this may sound stupid, but also make sure you're working on the correct layer... You know, the one with the object you want to cut out - it should be highlighted in your layer menu.

    
9. butcherboy on May 28, 2008 2:09 PM

   runescapehelpaz, Make sure you have an alpha channel in the layer you are working on. to do this, right-click on the layer you are working on and click on "Add Alpha Channel". The initial layer when opening or creating a file does not have an alpha channel by default. Hope this helps.
   
   Hogtied

    
10. Ashfame on June 13, 2008 1:34 AM

    Thanks buddy for this tutorial. Now I can do this pretty quickly. :)

     
11. Ale on July 1, 2008 2:46 AM

    I select with bezier ok, I close the loop, I press enter, I see the ants, I select Invert but....
    when I press delete, ctrl-k or other the background is still white, not checkered.
    any hints? I am using gimp 2.4.6
    I have tried this process from other tutorials, but I can't get it to work. what's wrong with me??

     
12. StockFox on July 13, 2008 6:26 PM

    This is great!
    
    Ok, but now the tricky part. How do you edit the foreground image once you paste it into the background. For example, I realize that I need to touch it up a little to make the merge look realistic, but I can't seem to get access to the pasted image to erase around the edges.
    
    Thanks in advance.

     
13. CJ on July 13, 2008 6:51 PM

    Hi. Good question.
    
    Making the edges seem like part of the picture is where a lot of artistry comes in. I can tell you the tools to use, but you'll need to be creative with them, and judge light, colour, and smudging for yourself. Also be patient. If you're aiming for a really good blend, use many tools, use them gently, and do only a little at a time.
    
    1) Find the "Smudge Image" tool (looks like a little hand with a finger sticking out). Use different brushes with it (hard circle, fuzzy circle, etc.) and set them to a low opacity (to start with). Then gently brush the edges of your image in different directions as appropriate.
    
    2) Use the "Eraser" with different brushes and opacities to soften very hard edges.
    
    3) Use the "Paintbrush" at a low opacity if you want to merge a back ground colour with the foreground image. Gently brush over the area and make the colours blend. Use a soft brush. Keep changing the colour to an appropriate one (use the eyedropper tool on the FG/BG dialogue).
    
    4) Don't forget you can "Select" the foreground image before you merge it with your background. This lets you fuzzy up the edges as needed. Find your options under the "Select" menu in your picture's window - they will include options like "Shrink" and "Grow".
    
    5) Don't forget to match the light and colour of the foreground with the background. No way I can cover this properly. You'll have to experiment for yourself with the huge ranges of options in the menus. Tip: start with "Layer"-->"Colours".
    
    Can't be any more specific I'm afraid. The art is up to you. Remember the biggest thing about using these tools is to use small opacity numbers and a range of brushes, particularly soft ones because they give subtler effects. Blend and merge, blend and merge, and have fun. :)
    
    Good luck!

     
14. Jason on July 26, 2008 2:47 PM

    @ale. To turn the white background into transparent go to the "layer" > "Transparency" > "Color to Alpha..."
    
    This will launch a window that will show you the result of turning the background color (white) transparent. Click OK and you are done!
    
    Good luck.

     
15. Ale on July 30, 2008 4:39 AM

    seems to work now. thanks!

     
16. Garrett on November 28, 2008 4:24 PM

    Thanks a lot for the awsome tutorial! GIMP is so complex its nice not to have to figure everything out on your own. Thanks again!

     
17. CJ on November 30, 2008 3:20 PM

    You're welcome. Glad it helped! :)

     
18. Anonymous on December 21, 2008 11:40 AM

    Finding these tips very helpful ... however, the image I need to make it's background transparent has nothing but turns and curves ... almost flame like. Is there a way to pick a color as the transparent mark? ie, set white as the transparent color for the entire image. Thanks...

     
19. CJ on December 21, 2008 6:35 PM

    This tutorial might help you. :)

     
20. StockFox on December 27, 2008 10:55 PM

    I meant to thank all you guys. This has been a very helpful conversation.

     
21. Anonymous on February 4, 2009 9:13 AM

    If I knew you, I would kiss your feet in person!!! So take the virtual feet kissing of thanks!!! I am clueless about working with graphic programs. I just got lucky today on my search and found your well written, easy to follow instructions!!!!! Thank you so much

     
22. CJ on February 4, 2009 10:03 AM

    Good grief! That's very nice of you! Glad it helped... :)
    
    I can well remember the frustration of trying to learn GIMP. It's a lovely little programme though - so hang in there! :)

     
23. [meadow] on March 14, 2009 1:14 AM

    Hello, i am very frustrated because i can see the checked grey white area after i clear away the selection. But when i copy the image to any where, it is not transparent, but the area that is cleared is black!!!Y!!! I jus can't figure it. Pls help.

     
24. Gimp Lover on March 14, 2009 7:53 AM

    Meadow - it sounds like you're trying to paste an image that still has transparency in it. You have three options:
    
    1) 'Flatten' the image (and automatically give it a block colour background - black is the default).
    
    2) Put your image onto the background of your choice before you try to export it out of GIMP.
    
    3) Save it in a file format that supports transparency. Jpegs and bmps do not allow transparency to remain in the image. Therefore, save a transparent image as a .png file - this is especially useful if you want a transparent image on a website, but bear in mind that not all browsers support transparent .pngs.

     
25. [meadow] on March 15, 2009 4:28 AM

    Thanks a lot for your response! Really appreciate it!

     
26. Danielle on May 23, 2009 9:40 AM

    thanks it helped a lot. and it worked! yes!

     
27. Anonymous on June 3, 2009 3:48 AM

    Thank you very much for this advice, it made it POSSIBLE to do this.
    
    As a new GIMP user (but with experience using other imaging tools), I must say the user interface of GIMP is horribly complex, and it appears some things can ony be done in "one way", like this.
    
    The user interface should be made simpler. In my opinion, there should be a pseudo-color "transparency", as this would make this activity much more straightforward and easy to understand.
    
    If an "alpha-channel" is required for deleting pixels, then it sould be automatically added as needed.

     
28. Anonymous on August 2, 2009 4:35 PM

    Just wanted to say thanks for taking the time to write this tutorial. In a couple of minutes I was cutting and choppng and marching with ants! Thanks!

     
29. Anonymous on October 6, 2009 7:39 PM

    How do you do this the other way around? Deleting the object instead of the background? I really need help.

     
30. Linnea on October 24, 2009 3:42 PM

    Thank you so much for this! So very helpful. Still helping dummies two years down the line ;)
    
    Last Anonymous (Oct 6 2009):
    
    I just did that by accident, all you need to do is don't invert. Just create the selection, and delete it.

     

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