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174 lines
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Episode: 3095
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Title: HPR3095: Intro to GIMP
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Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr3095/hpr3095.mp3
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Transcribed: 2025-10-24 16:38:41
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---
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This is Hacker Public Radio Episode 3,095 for Friday 12 June 2020.
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Today's show is entitled Intro to Gimp. It is hosted by Ahuka
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and is about 18 minutes long and carries a clean flag. The summer is
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an introduction to Gimp to kick off a new series.
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This episode of HPR is brought to you by archive.org.
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Support universal access to all knowledge by heading over to archive.org
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forward slash donate.
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Hello, this is Ahuka welcoming you to Hacker Public Radio
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and another exciting episode. And I am now going to start looking at
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something called Gimp which stands for the Gnu image manipulation program.
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And it's often referred to as the open source equivalent to Photoshop.
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It is a raster based program meaning that it operates on individual pixels.
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So does Photoshop. And this is distinct from what we call vector based
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programs which operate on lines and curves
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described by equations. The example of that in open source world might be
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inkscape or in the proprietary world Adobe Illustrator.
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Now photos are inherently pixel based so a raster based program is the appropriate
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tool generally speaking for working on photos.
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Little fun fact Photoshop originated in the area I live in as it began with the
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University of Michigan graduate student. And I live here because I went to the
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University of Michigan as a graduate student and just never left the area.
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So what started me on this was that I have a lot of old photos that I've been
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taking a look at that my wife and I have they go back to the 60s and 70s and
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some of them are in pretty rough shape. I'd like to see if I can fix
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some of these so I thought well you know this is an opportunity to
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learn what I can of Gimp but while the photos are my primary interest I'll
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take a look at the program more generally. Now to do that I need to find some
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resources. Well in this day and age that's pretty easy.
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YouTube has some good ones to start with and I've got links to all of these
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in the show notes and anyone who has followed my programs may have discovered
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by now I tend to have reasonably detailed show notes for
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things you can look up online. So here's some some YouTube ones
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good ones to start with how to use Gimp Beginners Guide,
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how to use Gimp Basics, Gimp in less than 10 minutes
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beginner's guide, Gimp Tutorial, Top 5 Photo Enhancement Techniques,
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and there's other things. There's the online you've got the Gimp.org
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Tutorials site, an introduction to Gimp Photo Editing Nine Things You Need
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to Know, how to use Gimp 20 Gimp 2.10 Tutorials for Beginners from the
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Davies Media Design Company, Gimp Basics, Best Tips and Tricks for Beginners
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from PC World, how to Gimp Tutorials for Gimp and Photoshop.
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So you has a lot of stuff there. So that's going to be where I start from
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and maybe I'll say something that will get you interested and
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you'll want to go beyond what I do in these simple tutorials to start with.
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Now the thing about software tutorials when you're searching online,
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I always tell people to be careful about when they were written and for which
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version of the software. A five year old tutorial may no longer reflect how the
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software works now. So if you stumble across this particular tutorial a few
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years from now, you should be just a bit wary. There are tons of resources here
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and that's a good thing but you know make sure you get the right resources.
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Now one of the things I want to mention as well, Gimp Magazine, which looks like it has
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stopped publishing, they did put out 12 issues before they stopped and it looks like they are
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still available from an organization called Issue.com, ISSUU. Now again link in the show notes.
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They had 12 of these things there about five years old. So based on what I just said to you,
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you might find some interesting stuff that just be careful. Things might have changed a little bit.
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So let's say you've decided, ah, interesting idea. I should try this Gimp thing
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that Hooker is talking about. Well step one is install the software.
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Now I'm on Linux and some distros of Linux may have this included automatically,
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but I just checked and I have a number of graphics programs installed, but when I looked I did not
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have Gimp installed. Well there is a downloads page at Gimp.org and it correctly spotted that I'm
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using Linux and offered me suitable packages, but I find it's much better to work with my
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package manager for my distro. And I've got a good package manager installed.
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If you're not using Linux, I will just mention in passing, they have installation files for OSX
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and Windows as well. But on my Linux distro, I prefer Synaptic, so I just opened it up by
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installing Gimp. I also made sure to install some additional help files that are in English.
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There's files in other languages as well, quite a few of them really. So
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after doing all of that, I had Gimp 2.8.22 installed onto my Kabuntu 18.04 box,
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which is what it will be until they decide to push me to the 20.04. I like to stay with long-term
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support releases. As I mentioned before, I'm at the point in my life. I don't want to work on my
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computer. I want to work with my computer. So something that makes things easy is good.
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Now, upon opening Gimp, there is something a little disconcerting to me at least.
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Instead of being a single program window, it opens several disconnected windows, laid over whatever
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program was already open. That's not something I am used to. So instead, I looked at the central
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window where I had the usual menus and clicked on the Windows menu and selected Single Window
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mode. Now, as my investigations move forward, I may become convinced I should switch back,
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but I'm very used to each program having one big window.
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Now, with that single window, there are five sections. The toolbox, which is on the upper left,
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tool options, which is on the lower left, the canvas, which is in the middle, layers, channels,
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pads, and undo, which is in the upper right, brushes, patterns, and gradients, which is on the
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lower right. So those are your five main sections. Now, the first section toolbox can be further
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broken down into various kinds of tools. The selection tools include rectangle, ellipse,
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free select, fuzzy select, select by color, scissors select, and foreground select.
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Generally, the first step in most operations in Gimp will be to select the objects you're
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going to manipulate. So you'll use the selection tools a lot, and they are the first of the tools
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to show up in the toolbox. They let you select the area of your image that you want to work on and
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let you make changes there. Note that when you mouse over any of the icons, you will get a tool tip
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that describes what it is. Then, down at the bottom of the group are the various paint tools. Bucket
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fill, blend, pencil, paintbrush, eraser, airbrush, ink, clone healing, perspective clone,
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blur sharpen, smudge, and dodge burn. Then in the middle of the window are the transform tools.
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Move alignment, crop, rotate, scale, shear, perspective, flip, and cage.
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Then the rather miscellaneous tools. One that looks like a capital A is the text tool. Let's
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you draw a text box and put text into it. And between the select and the transform group, you will
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find paths, color, picker, zoom, and measure. Now again, this is for my installed version 2.8.2.2.
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If you have a different version, you may have slightly different tools, although almost all of them
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should be the same, regardless of version. Now, tool options are below the toolbox,
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and they give you additional control over whichever tool you have selected. You click on a tool
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to select it, and then the tool option panel will display relevant options you have. For example,
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if you select rectangular select as your tool, you will get options like replace, add, subtract,
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and intersect. And then you can add things like rounded corners to your selection.
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But if you had picked, say, the pencil tool, you would get options like opacity, brush size,
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pencil hardness. So the options you get are appropriately matched to the tool.
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Now, if you take a look at the upper right layers up here there, and they are very important.
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Gimp operates on layers, and an image can have many layers while you were working on it.
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You can think of this like a stack of transparencies with each transparency holding an object of
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some kind. That could be an image, a text box, a colored oval, or any of the many things Gimp can produce.
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You need to get in the mental space of using layers proficiently if you're going to be a good
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user of Gimp. This is also true of Photoshop, but I am sticking to open source here.
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To work with layers, make sure that you have selected the Layers tab, which is in the top left
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of that window. In the Layers channel's paths undo window, and that window itself is in the upper
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right of your screen. So with the Layers tab selected, you can then add layers as needed.
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There is a Add New Layer on the bottom left of that window, and build up your image gradually.
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One of the great advantages of this approach is that you can easily change your mind on something
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by just removing a layer. If you decide you don't like what it did. This is like a gazillion
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times better than using undo. Believe me, Control Z is in my genetic code by now,
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because I use it so often. But this is better. You can, for instance, remove a layer that maybe you
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did a week ago, and there are five other layers that you've added since on top of it.
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Well, you can just go back and pick that one layer, and get rid of that.
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And then all of the more recent ones are still there, just fine. With the undo, that's not
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an easy thing to accomplish. So we'll get into layers in much more detail later on.
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But for now, let's just say this is a key concept in working with Gimp.
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Of course, finished images do not in our experience come in layers.
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So this brings us to another key concept, the working file. When you're working in Gimp,
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you are building a working file. This is, again, similar to Photoshop. A Photoshop native file has a
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.psd extension, while the Gimp native file has a .xcf extension. And I looked that up
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and what is .com gave me this information.
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Xcf is a file extension for an image file native to Gimp. Xcf stands for Experimental Computing
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Facility. Similar to a Photoshop document, PSD. Xcf files support saving layers,
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channels, transparency, paths, and guides. Yet don't support saving the undo history.
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Xcf files are supported in other image editors. Yet due to how often the Xcf format is revised,
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it isn't recommended for use as a data interchange format. On a side note, the name Xcf honors
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the Gimp's origin at the Experimental Computing Facility of the University of California,
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Berkeley. And I've put again a link in the show notes if you want to find where I got that.
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So what this means in practice is that as you are working on the image, you can save it,
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and you will have an Xcf file. This file can be worked on until the image is complete.
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And at that point, you would export the image as an image file like, for instance, a JPEG,
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a GIF, a PNG, or any of the other image formats that you happen to prefer.
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Now note that if you later want to make changes, the exported image file no longer remembers
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any of the things like layers, channels, and so on. But if you have saved your Xcf file,
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you can open that up and make any changes you wish.
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So it's a good idea to save your Xcf file often and keep it around for future use.
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One idea is to have two directories, or directory trees, if that's how you roll,
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one for the Xcf working files, the other for exported finished files.
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And you probably want to get used to saving often as you work, since a crash can cause you
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to lose all of your unsaved work. GIMP does not, at this point, have auto-save capability.
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So far as I know, there is a script available as a plugin, and I've put a link to that in the
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show notes. If you're the sort of person who wants to go down that path, I have not learned
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how to do plugins in GIMP yet. I'll probably get there at some point when I do. I'll do a tutorial
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about that. But if you're more advanced than I am, it's written in Python, it's at Github,
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and the link is there, so you can check it out. Now, just to level set all of this, I
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I think I've said a few things already that would have given you the impression that I am not
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the world's foremost authority on this. This is more a case of me documenting as I learn and
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sharing that with the HPR community. Please do not consider me the last word on any of this stuff.
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There's probably lots of people that know more than I do about this. I just haven't seen
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anyone do anything on HPR about it, and I thought, well, I can do that. I'm going to do a number
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of shows that are essentially tutorials, and those of you who have been around for a long time
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may remember the Libre Office tutorials I did. I guess the idea is to try and do something like that
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with GIMP, and we'll see where that goes. This is Huka for Hacker Public Radio. I am going to
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sign off now, and as always, remind you to support FreeSoftware. Bye-bye!
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You've been listening to Hacker Public Radio at Hacker Public Radio.
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