Transparent background in GIMP images.

[PGTips91]

I'm not sure if this has been covered elsewhere, but I have been learning to select a foreground image, delete the rest and export with a transparent background so that the image displays without any surrounding colour-difference.

The key when starting with a jpeg image, I have learned, is to add transparency to it. Then when the background is deleted the transparency cross-hatch will show through. The amended image has to be saved as a .png or .gif as .jpg cannot handle the transparency [or layers].

Here is a photo of penguins, uploaded to my Picasa Web site.  

And here is how it looks before final saving as a .png file      with the transparency layer indicated by the checker-board pattern.

And now the final result after saving as a .png image.  

Now if someone can help me with my selection techniques, to get the curve of the penguin's back more neatly, I would be grateful. Too much like hard work the way I am currently doing this.

Paul

[conholster]

Hey, nice tutorial

Now if someone can help me with my selection techniques, to get the curve of the penguin's back more neatly, I would be grateful. Too much like hard work the way I am currently doing this.

Use the Quick mask (Shift+Q) and draw the selection with one of the Fuzzy brushes. Adjust the size of the brush with the Scale slider.

When you're done with the selection either cut and paste to a new layer or go to Select->Invert and then use the erase tool.

[PGTips91]

Thanks, conholster, I can't quite get the hang of using Quick-mask. Will have to play around with it some more when I am not so tired. I need to get the GIMP help files installed locally, too, but not quite sure how to do that. Probably with Synaptic, I guess.

I experimented with using By-colour-select, for the initial grab at the background, then Free-select +/- holding down the 'Shift' key to add to and the 'Ctr' key to subtract from the selection. With the image displayed at 400% I could just about follow the pixels with my selection and much more quickly grab the areas desired.

By reversing the selection and using the same technique, I could quickly select all the previously unselected areas of white on the penguins.

I also discovered that by choosing

Code:

> File > Save for Web ..

that I was able to reduce the file-size from 158 KB to just 54 KB. And there is no perceptible difference in the visual quality, as far as I can see.

From Transparency

From Transparency

Paul

PS Getting the hang of the quick mask, now, just toggle it on and off with the  'Shift +Q' and paint 'white' to include, and 'black' to exclude from the selection.

[petrikNZ]

Save for web?

What version of GIMP has that?

I know it's an option in photoshop but I don't have it on GIMP

[PGTips91]

Save for web?

What version of GIMP has that?

I know it's an option in photoshop but I don't have it on GIMP

Hi petrikNZ,

I'm using GIMP 2.6.3 under Linux, ArtistX 0.6.

From Transparency

Paul

[Paul LeBlanc]

 Very nice info PG, I also had not known Gimp was able to do this.

[PGTips91]

Thanks, everyone, for the positive feed back and help. I am grateful and pleased to have learned something and shared something.   

Paul

PS You should take a look at Linux Internationals Forum for loads more smileys!

[petrikNZ]

I wonder if you're running a plugin to have that. If not I suggest you don't upgrade. On the about screen of the GIMP version I have it says 2.6.6 (from the Ubuntu repositories if I remember correctly, I sometimes install direct but not this time/one I think) and it's not in my menu.

[PGTips91]

I wonder if you're running a plugin to have that. If not I suggest you don't upgrade. On the about screen of the GIMP version I have it says 2.6.6 (from the Ubuntu repositories if I remember correctly, I sometimes install direct but not this time/one I think) and it's not in my menu.

Hi petrikNZ, my fellow Aucklander! You are right on the button there. I've just checked my GIMP and found, in the 'Procedure Browser', that it has 1,318 procedures, among which I presume is that special one which allows me to save, optimised for the Web. Too late in the night to look further!

This particular copy of GIMP comes in a 3.2 GB ISO for ArtistX 0.6, so it has just about everything that is available for graphics, videos, sound, etc built in ready to use. Unfortunately there is not a very active forum for this distro so it is a bit harder to find out the fine details such as this issue.

There is a new version out just recently, 0.7, which I have as a LiveDVD only as yet, but hope to be able to install it on the hard drive soon.

Paul

[Gozzin]

Can you draw directly on a transparent background?

[PGTips91]

Can you draw directly on a transparent background?

Hi Gozzin,

Yes, you can.

Just create a new image of the required dimensions, add the alpha channel to give it transparency, then 'select all' and delete the white background. Now you can paint anything you like and the 'background' is just a transparency. You will need to save it as a .gif or a .png to keep the transparency.

Code:

File > New
Layer > Transparency > Add Alpha Channel
Select All > Edit > Cut
Paint as you wish
Save to GIF or PNG format to retain the transparency

I've attached an example.

Paul

[Gozzin]

Wow!!!!! This is TOO COOL! no more taking the blasted lasso and going around the edges of stuff.

[MeeMaw]

Great picture, Gozzin!!!!

You're getting the hang of layers apparently.........

 

[Gozzin]

 Well it's starting to make a little sense...Still i find the eye chain stuff very confusing .
Now copy/paste.THAT'S logical.

[rji]

I know it's an option in photoshop but I don't have it on GIMP

It is a plugin:  http://registry.gimp.org/node/33