Questions about the fuzzy tool and transparencies

otherwhirl · **Joined:** Dec 29, 2013 **Posts:** 159

GIMP Version: 2.8.10
Operating System: Mac OS
GIMP Experience: Beginner Level

Ok,
So I know I'm on a roll here with 'noobish' questions but bare with me here guys (I learn fast...):hehe

I notice whenever I add an alpha channel and apply the fuzzy tool to a file that has font or images with non transparent backgrounds that although the transparency gets made, there is a noticeable
outline of the previous background color around the font and/or image.

How can I clean this up? I want just a straight and clean transparency behind the font or image in the foreground.

I created a screencast here:
View My Video

he4rty · **Joined:** Aug 30, 2012 **Posts:** 2174

Basically when you open the fuzzy select tool, in the tool options window you want to increase the threshold settings.

otherwhirl · **Joined:** Dec 29, 2013 **Posts:** 159

@ he4rty

Ahhh I see why it's set soooo low by default LOL it nearly chopped off the head of my design at 50% :hehe

Thanks he4rty another simple riddle solved....

he4rty wrote:

Basically when you open the fuzzy select tool, in the tool options window you want to increase the threshold settings.

K1TesseraEna · **Joined:** Sep 22, 2012 **Posts:** 2089 **Location:** US

he4rty beat me

http://docs.gimp.org/en/gimp-tool-fuzzy-select.html
I'd use the Color Select tool. Fuzzy selects only contiguous pixels.
In either case you need to adjust Threshold value, select and press Del key.

Another way - is to Color Select text with default Threshold, go Select>Shrink and shrink the selection 1 or 2 px.
Invert the selection, Delete.

otherwhirl · **Joined:** Dec 29, 2013 **Posts:** 159

@ K1TesseraEna

Awesome guys!

It won't be long before I'll be MUCH more comfortable with Gimp.

REALLY appreciating this forum. Whithout a question it is slowly becoming one of my favs and certainly my fav Gimp forum :bigthup

K1TesseraEna wrote:

he4rty beat me

http://docs.gimp.org/en/gimp-tool-fuzzy-select.html
I'd use the Color Select tool. Fuzzy selects only contiguous pixels.
In either case you need to adjust Threshold value, select and press Del key.

Another way - is to Color Select text with default Threshold, go Select>Shrink and shrink the selection 1 or 2 px.
Invert the selection, Delete.

ofnuts · **Joined:** Oct 25, 2010 **Posts:** 4812

Both fuzzy select and color select are evil, because they can only do a full selection of pixels. To create transparency without jagged edges or faint remnant of the background, see here.

otherwhirl · **Joined:** Dec 29, 2013 **Posts:** 159

Hey thanks ofnots,

I was just checking out this page: Because of malware being found in SourceForge downloads, this link has been removed.

Hmmm.... how do I actually get to the script/function for automating removal of backgrounds to transparencies?

So I go here and then what?

ofnuts wrote:

Both fuzzy select and color select are evil, because they can only do a full selection of pixels. To create transparency without jagged edges or faint remnant of the background, see here.

PhotoComix · **Joined:** Apr 12, 2010 **Posts:** 5870

otherwhirl wrote:

I was just checking out this page: Because of malware being found in SourceForge downloads, this link has been removed.

Hmmm.... how do I actually get to the script/function for automating removal of backgrounds to transparencies?

So I go here and then what?

Installation instruction are on the right on that page
BUT obviously you will need also the files to install that are here Because of malware being found in SourceForge downloads, this link has been removed.

ofnuts · **Joined:** Oct 25, 2010 **Posts:** 4812

otherwhirl wrote:

Hey thanks ofnots,

I was just checking out this page: Because of malware being found in SourceForge downloads, this link has been removed.

Hmmm.... how do I actually get to the script/function for automating removal of backgrounds to transparencies?

So I go here and then what?

ofnuts wrote:

Both fuzzy select and color select are evil, because they can only do a full selection of pixels. To create transparency without jagged edges or faint remnant of the background, see here.

There is no script to remove the background because you have to create the initial selection yourself:
- start fuzzy selection
- click on background
- shift-click on any missed areas (inside of letters (A, O, B, R, P...) , for instance) to add them.

This part cannot be scripted efficiently because there are often parts of what you want to keep that may be the same color as the background you want to remove. For instance the the WordPress logo you may want to keep the white inside the logo. This is why you can't use the color selector for this purpose, and why you are the only one to know where to click to create the selection.

The rest is utterly simple:
- "Select/grow" by 1 pixel
- "Colors/Color to alpha" and color-pick the right color.

Takes all of 5 seconds, initial selection included.

otherwhirl · **Joined:** Dec 29, 2013 **Posts:** 159

Nvm... in other words, there is no actual plugin for removing backgrounds.

no problem it is very simple to do (once you know how to get the best result... :roll:

)

Thanks

ofnuts wrote:

otherwhirl wrote:

Hey thanks ofnots,

I was just checking out this page: Because of malware being found in SourceForge downloads, this link has been removed.

Hmmm.... how do I actually get to the script/function for automating removal of backgrounds to transparencies?

So I go here and then what?

ofnuts wrote:

Both fuzzy select and color select are evil, because they can only do a full selection of pixels. To create transparency without jagged edges or faint remnant of the background, see here.

There is no script to remove the background because you have to create the initial selection yourself:
- start fuzzy selection
- click on background
- shift-click on any missed areas (inside of letters (A, O, B, R, P...) , for instance) to add them.

This part cannot be scripted efficiently because there are often parts of what you want to keep that may be the same color as the background you want to remove. For instance the the WordPress logo you may want to keep the white inside the logo. This is why you can't use the color selector for this purpose, and why you are the only one to know where to click to create the selection.

The rest is utterly simple:
- "Select/grow" by 1 pixel
- "Colors/Color to alpha" and color-pick the right color.

Takes all of 5 seconds, initial selection included.

ofnuts · **Joined:** Oct 25, 2010 **Posts:** 4812

otherwhirl wrote:

Nvm... in other words, there is no actual plugin for removing backgrounds.

There is the foreground selector, but it is complete overkill for the simple case of an object over a uniform background. And in that simple case, the plugin can't be any simpler than the direct method (at best it would do some hand-holding).

otherwhirl · **Joined:** Dec 29, 2013 **Posts:** 159

ok gotcha...
I'll stick with the basics... Thanks again :bigthup

ofnuts wrote:

otherwhirl wrote:

Nvm... in other words, there is no actual plugin for removing backgrounds.

There is the foreground selector, but it is complete overkill for the simple case of an object over a uniform background. And in that simple case, the plugin can't be any simpler than the direct method (at best it would do some hand-holding).