GIMP for dummies – How to highlight part of image !!!!!!

1 06 2008

So how do you highlight a part of an image using the Gimp?. My question exactly since I don’t know much about pixels inverts, color and layers this isn’t exactly easy for me to do and Googling for an answer I found people talking about inverting the selection and brushing away WTF.

Gimp for dummies

Obviously the first thing I did was to open GIMP and look for the highlight button after failing I tried other image editing aps. In open office draw the help file actually talks about a highlight tool bar button but I couldn’t find it in the 10 000 other tool bar buttons and the help file didn’t specify a menu item I can use. The others like GNU paint, Xpaint and even Tux paint didn’t provide “the magic button”.

Help ???

Lucky for me I have low friends in high places. So I mailed one of them who claims to be a graphic design student. What I got back can only be described as the graphic design student way of saying RTFM or Read The F***** Manual. The fact that must have slipped the mind of the friend in question is who actually helped her install Xbuntu and GIMP in the first place on her useless old G3 Mac.

I include the screen shots (without permission ;p) and some of my own comments on highlighting a part of the image in GIMP:

1. Open the image with GIMP

2. Select part to highlight

Using the Rectangle Select Tool select the part of the Image you want to highlight. After selecting with the Rectangle Select Tool the selected part will be surrounded with a box of moving dashed lines (Showed in 3).

Step 2

3. Change color

The color that you want to use to highlight can be selected on the top box of the Foreground & Background colors that is located at the bottom of the main tool bar the default seems to black and white. After clicking the black box a window named Change Foreground Color will pop up. From the small notebook select the tab on the most right. In this case the yellow color was selected. The Foreground color should now be yellow or the color selected in your case. The area you want highlighted will still be surrounded in a dashed box.

Select color

4. Fill the selected area with Bucket Fill Tool

It was this step that provided the Eureka moment for me since the previous steps was obvious. Select the Bucket Fill Tool. Once selected look out for the fill settings just under the main tool bar. The trick is that the default Opacity is set to 100. It seems Opacity means almost the same as transparency except when the opacity is set to 0 the color is 100% transparent and vice versa. Select a opacity of around 30 (experiment for best effect). Select FG color fill. And select Fill similar colors, leave the rest of the settings as is. Lastly click inside the area selected in step 2  and the area should be “Highlighted”


None of this is possible in the first place without great free and open source tools like the Gimp running on a great operating system like GNU/Linux.




27 responses

21 02 2009

sos un campion

31 07 2009

Thanks – that was useful…

25 08 2009

No problem glad i could help

20 10 2009

Great post for cool programmers but dummy designers 😉

29 10 2009

Champion, thanks for that!

6 11 2009
Big Dan

Thank you! I’ve been wondering how to do this for a while. I use it for screenshots in tutorials. 🙂

12 02 2010

Thanks for this useful information. So long.

13 02 2010

Glad I could help

20 04 2010

Super helpful – thanks a ton.

1 07 2010
4. Area estimation of images with defined edges « TiSzA’s blog

[…] 2010.  Area estimation of images with defined edges.  Applied Physics 186. [2] Hattingh, F., 2008. GIMP for dummies – How to highlight part of image. [3] Vergara, J., 2009. Area estimation for images with defined edges. [4] Wolfram, 2010. A […]

25 09 2010
Pulkit Kaushik

Thanks! It worked!

8 12 2010

Thanks, very helpful!

2 01 2011
2010 in review « Defcon3 by Fredre

[…] The busiest day of the year was November 10th with 52 views. The most popular post that day was GIMP for dummies – How to highlight part of image !!!!!!. […]

26 01 2011

An improvement over your method is to use Burn Mode in the bucket fill settings (the first drop down) instead of opacity. That way you can get more vivid colors.

26 04 2011

Thank you!
It was just what I needed 😀

30 07 2011

This made what I wanted to do very easy. Thank you very much for sharing it.

23 01 2013
Stanley Soman

Your post had wit and charm. Thank you for such clean instructions.

5 08 2013

Without experienced developers on-hand, many of these problems became overlooked, and
many substandard creatively designed websites are still around today, with more and more being sent live on the world wide web every day.
Well that is another aspect of web design called Search
Engine Optimization. This will be a static image of what your website is going to look like,
as it is much faster to edit a graphic than to edit a coded website.

25 03 2014

Thank you SO much! I am a knucklehead technophobic grandmother who is trying to put my genealogy blog up for my little people! Your explanation actually made sense to me so I managed to something even my husband couldn’t! Genius!! 😀

27 08 2014

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22 10 2014

Another way that works really well is to create a transparency layer, on that layer select what you want to highlight. Fill the selection on the transparency layer with your highlight color and change the transparency layer’s blend mode to ‘darken only’.

8 06 2015

thank you!

7 07 2015

can you elaboate how can we highlight text on a photo in GIMP

8 01 2017
Speaking Out

Kevin: I did not understand how to find the darken only mode (I do not know alpha so on well “yet”) Fill the selection on the transparency layer with your highlight color and change the transparency layer’s blend mode to ‘darken only’.

While trying to figure that out, I was mustering around and found another possible solution (at least for me to highlight long legal documents)

New transparent layer to text layer (or in my case scanned document)

I made a box and highlighted it with the colour (pale yellow)

Then Layer again, Transparency and I tried out…

Colour to Alpha and got a pretty transparent layer over my text without the opacity. If you are still on the thread can you detail the steps in your reply?

Thanks much!

17 02 2017

Hey. How do you highlight an area on an image using a rectangle outline using gimp? Hope i made sense. Thanks

20 09 2017

Thanks! I needed to do this on my Mac with media cuttings and Preview didn’t give me the options I needed. Your guide was so easy to follow! 🙂

11 01 2018

Note that the transparency dialogue box may need to be revealed with Windows -> Dockable Dialogues -> Tool Options

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