hpr-knowledge-base/hpr_transcripts/hpr3180.txt

Episode: 3180
Title: HPR3180: GIMP: Miscellaneous Tools
Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr3180/hpr3180.mp3
Transcribed: 2025-10-24 18:21:33

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This is Hacker Public Radio episode 3,180 for Friday 9 October 2020. Today's show is entitled,
Gimp, Miscellaneous Tools,
and is part of the series Gimp. It is hosted by Ahuka
and is about 13 minutes long, and carries a clean flag. The summary is,
these few remaining tools are important. But don't fit neatly into one category.
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Hello, this is Ahuka, welcoming you to Hacker Public Radio
and another exciting episode in our Gimp series.
And what I'm going to do today is take a look at a few miscellaneous tools
that don't fit neatly into any one category, but they're important.
So, you know, we do need to take a look at this. Now, to recap briefly,
there were tools that fall into groups like selection tools, paint tools,
transform tools, and color tools. We've covered each of those groups in previous episodes.
But the ones that are left are kind of a grab bag.
And there are five of them that we want to take a look at.
Paths, zoom, measure, text, and something called giggle operation.
And that'll be fun.
So, they don't have anything to do with each other, but they're useful.
So, we want to take a look at them. Now, again, as with any of the tools we've looked at,
practice makes perfect. So, what you probably want to do is open up Gimp
and either create a blank image or open a photo to work with these tools.
Now, I would suggest a photo for most of them is probably good,
but a blank image will help for things like the text tool.
Now, all but the giggle operation tool, all of the others have icons in the toolbox
and all of them are accessible on the tools menu.
Now, the first one is called the Paths tool.
And it lets you create and manipulate Bezier curves on your image.
Now, I've put a link in the show notes to a discussion on Wikipedia of Bezier curves.
So, that should prove interesting if you want to dig into that a little bit more,
but you probably have seen things like this before if you've done any graphics work.
So, you click on the icon in the toolbox.
Now, this one does not have a pop-up dialog box like many of the other tools do.
Instead, we are now going to look at the right sidebar,
which we haven't really paid much attention to so far.
And on the top of that right sidebar, there's a section we'll use a lot more often when we get to layers.
The first tab is layers, the second is channels, the third is paths,
and the fourth one is undo.
You can see individually each of the, you can go back to any undo level.
So, all useful stuff over there.
But the paths one is the one we're going to take a look at right now.
So, you probably want to click the paths tab and just have that open.
Now, there is also a tool options for this tool, which is on the bottom of the left sidebar,
just as with all of the other tools.
Now, Bezier curves are defined by anchor points and tangent lines, essentially.
And you can manipulate the curve by moving the anchor points or twisting the tangent lines or both.
For example, if you select the paths tool and then select design mode in the tool options
and click on the image, you will get one anchor point.
Click again on a different part of the image and you'll get a second anchor point
with a straight line connecting the two.
Now, this all works the same as the selection tools we looked at earlier.
One of these points is active, the one you most recently clicked on.
And that one is the one that is an empty circle instead of a solid dot.
From there, you will have a tangent line with squares on either end.
You can then adjust the curve by moving one of those squares to reshape your curve.
Now, note that if you check the polygonal or polygonal, I'm not quite sure how to pronounce that.
Boxing the tool options on the lower left, you'll get straight line segments between the anchor points,
which makes it very similar to the freeform select tool.
But the real power of this tool is the curves.
And so, having the polygonal option is helpful if you want to do a mix that combines curve sections and straight line sections.
Now, when you get to the end, you want to be able to connect all of this,
but to connect it, what you need to do is control click on the very first anchor point to connect it to the last anchor point.
Now, when you do this, you've got a complete selection.
And so, you can then cut this image out and use it in another image.
Now, you fine tune your path by using edit mode.
This lets you add anchor points in the middle of your path, for instance.
And you enter edit mode by using the control key as you click if you don't want to keep changing modes.
Used with other tools like the zoom tool, this can let you draw very precise outlines around objects in a photo.
If you then click selection from path in the options on the lower left, you can do anything you want with it,
such as copy the selection and insert it into another image.
And this makes the path's tool extremely useful.
Paths can be saved as well.
To do this, right-click on the path in the upper right section and select export.
Save it as a .svg file, and you can then open it up in another image, the import, but also in another program.
svg stands for scalable vector graphics, and that is the type of graphic that can be rescaled without any problems because it is not raster based.
But instead, based in equations.
So, you could open this path in Inkscape, for instance, which is the premier open source vector graphics program.
And you can also import from Inkscape.
Gimps vector graphics tools are not all that powerful.
It really is a raster program, but having them there is handy.
Finally, the path's tool allows you to do other things as well.
You can paint along a path.
You can stroke the path, which sounds vaguely dirty, but really all it means is drawing a line, which can be dotted or dashed, or all of the different styles you can use for lines.
You can even write text that follows a path.
So, you see, this tool is really very useful.
Next, the zoom tool. This one is pretty straightforward. You can zoom in or zoom out.
But it is very useful for making precise edits since you can zoom in to the point that you can see individual pixels, which can be very helpful in making a selection.
Whether you are using the selection tools discussed previously, or the path's tool discussed above.
Note that you can also control the zoom level very precisely using the percent zoom setting, which is in the status bar on the very bottom.
This will let you type in a percentage for the zoom. If the image is at 100%, it is no zoom at all.
Less than that, it's zoomed out, and higher numbers are zoomed in.
And next to it is a drop-down that lets you pick from some pre-selected zoom levels.
Next, I want to talk about the measure tool. This lets you measure the distance and pixels between any two points in the angle of the line connecting them.
To use this tool, click on the first point, and holding the mouse button drag the cursor to the second point.
On the image, you will see the line connecting the two points and an angle marker.
But the actual data is on the status bar at the bottom right next to the zoom indicator.
And you will have a series of numbers. The first number is the actual distance computed using the Pythagorean theorem, and I checked. It is accurate.
The second is the angle away from the horizontal, and the numbers in parentheses are the horizontal and vertical displacements between the two points.
You think of those as coordinates.
Now, the text tool. This is mostly standard if you've ever used a text tool in any graphics program such as LibreOffice Impress.
You draw a box and start typing in text.
When you draw the box, a window pops up where you can select font, size, and so on.
I assume most people have seen something of the sort before, and this is very standard.
But there are a couple of things to point out that are not exactly standard.
So I want to mention those.
So the first is Hinting, which is a technique for making fonts more legible at smaller sizes.
There's a full discussion about it on Wikipedia, link in the show notes, if you want to get in the weeds about this.
But for most people, the idea of making small sizes more legible is probably sufficient.
Now, the other is anti-aliasing, which you probably heard up before, which is used in computer graphics to reduce the jagged edges that can appear, particularly when something is scaled up.
There is a nice brief definition at Robopedia, again, link in the show notes.
So these are things you wouldn't see in every text tool that you run across, but in graphics, they're very good to have.
Finally, Gagel Operation.
Gagel is GEGL. It's an acronym.
And it stands for Generic Graphics Library, and it was introduced in GIMP 2.6.
It is continuing to be developed, but as of GIMP 2.8, it was still not quite ready for normal use.
The documentation carries this warning.
Gagel is in a very early phase and still under construction. The Gagel Operation tool is experimental, link in the show notes.
However, if you look at the documentation for GIMP 2.10, which is the most current version as I write this, you see, instead, GIMP 2.10 is nearly fully ported to GIGEL.
You will find here some operations that are still experimental, and I'd link that in the show notes as well.
So you can see from this that GIMP is developing this and making it central to GIMP's further development.
Now, there's a nice YouTube video explaining how Gagel is the future of GIMP, again, link in the show notes.
For instance, it supports high-bit depth images, non-destructive editing, and beginning in GIMP 2.10, the GIGEL filters will be replacing the filters GIMP had previously, and so on.
So, to use this tool, you go to the Tools menu and select GIGEL Operation, and you will get a dialog box with a drop-down.
So, pick an operation and click the drop-down and make a choice. I have to be at least 50 choices here.
Not that I counted them, it just does a lot.
Many of them are not immediately clear to me, but some of them are things like newsprint and Gaussian blur and so on.
For each tool, a settings dialog will open. Remember, keep preview checked so you can see what your changes are doing.
And remember that the reset button will always get you back to your starting point.
Now, because Gagel is where GIMP is going, I have made the choice to support the principal developer, and I'm probably not pronouncing his name anywhere near correct.
He has a Patreon account. I have signed up for monthly, you know, just a few dollars donation.
As I have said many times, and we'll continue to say many times, I advocate supporting free software.
And since I'm using this wonderful program, I intend to help make it better through my financial contributions.
And while Gagel is not 100% there yet, it is exciting to see where it can go.
Now, this does finally complete our look at all of the tools available in GIMP.
Again, open an image and practice using these tools to get familiar with them.
And next time, we're going to take a look at brushes.
So, this is Ahuka for Hacker Public Radio, signing off, and as always encouraging you to support free software.
Bye-bye.
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