Saturday, September 26, 2009

GIMP: How To Install Scripts & Plug-ins To Gimp (Beginners)

Mac users read here.

To add brushes, gradients, plug-ins, and scripts to your Mac OS X follow the path as described below. Go to Users/homefolder/library/applicationsupport/GIMP.

Open the GIMP folder and find the appropriate folder…drop them into the correct folder.

Click image to enlarge.

Windows 7 & Vista users can watch a YouTube video on installing GIMP scripts here. The audio seems louder than usual, so be prepared to turn down the volume. (Note: Plugins [*.exe and *.py files] are saved the same exact way, except they go in the "plug-ins" folder)

XP Users (especially those using Internet Explorer as a browser) click here.

Linux users read here.  Also a few Ubuntu screenshots of GIMP Edit/Preferences/Folders (the correct folders for plug-ins and scripts are shown here):



At one point, I found myself on the GIMP Registry not knowing a thing about how to install scripts or plug-ins. The fundamentals of how this is done is documented on the site, located here. But before you go running off to check out that link for the information you desperately crave, stick around and view the screenshot instructions I'm posting below:

So you're browsing the GIMP Registry and you find a script or plug-in that sounds interesting and you want to try it. No problem.

If it's a .scm file, right click the actual link and choose "Save Link As". You'll see this prompt below:

Now you'll need to browse in explorer to save it to the right place. Since it's a *.scm file it needs to go in GIMP's script folder, as shown below (Vista):


In Windows Vista, the path to the GIMP scripts folder is C:\Users\Your User Name\.gimp-2.6\scripts. In Windows XP, the path is C:\Documents & Settings\Your User Name\.gimp-2.6\scripts.


The path for plug-ins are at the same location but instead of the scripts folder, you put the plug-ins in the "plug-ins" folder.

Notice that the plug-ins folder is directly above the scripts folder.

Plugins or scripts that come in a zipped file have to be handled differently, because you want to extract the files from the zipped file into the appropriate folders as shown above. Simply double-click the zipped file to extract them.

For adding new scripts, all that is required is that you refresh the scripts under Filters - Script-Fu - Refresh scripts. Adding new plug-ins, however, require that GIMP be closed and restarted. For most plug-ins, the most obvious place to find them is in the Filters menu, unless the Plug-in author instructs otherwise.

Scripts on the other hand are a little more tricky to find if the information on the GIMP Registry is lacking. One trick to finding where scripts are listed in the menus, is to open it and check out the register, located toward the bottom of the script file:

Sure enough, this script can be found under Filters - Light and Shadow, as indicated on the last line above.

Python plug-ins can be opened with an editor, but DO NOT OPEN executable plug-ins with an editor (e.g. someplugin.exe). If you cannot find a plug-in location in the menus, go to the Plug-in Browser under Help on your GIMP menu bar. (Thanks Saul!)

Most importantly, READ THE POSTS AND COMMENTS for the script or plug-in you are planning to use BEFORE you download it, and make a note of special instructions for the handling of that particular script or plug-in. Print it out, if you have to.

If all else fails, direct your comments to the author of the plug-in/script for logging errors and asking for additional instructions. The best way to get help is to clearly define your problem, including any error messages, and be specific about the problem. Don't post new comments on a new forum subject that read like this : "It's not working! HELP HELP HELP!" That fails to explain anything to anyone, and it's downright lazy and rude. Instead, run a checklist in your comments, that explain, that you downloaded the file correctly, it's in the right folder as indicated in the instructions. Specify your operating system and version of Gimp (i.e., using Vista 32 bit, GIMP 2.6.7) List error messages verbatim, and if it has a number assigned to it, include it.

We were all noobs at one point or another, so it's understandable that people are going to need a little extra help in getting started. The best thing you can do to help others help you, is be as helpful as you can, yourself.


If you use Notepad to save *.scm files, pay close attention to what you are saving it as, and where you are saving it to:

See the "Save as type:" showing Text Documents (*.txt)? That needs to be changed to "All Types"

Wednesday, September 9, 2009

GIMP: Displacement Water Reflection Tutorial (*Beginners*)

NOTE: This tutorial was taken in part from here. At the time, I had a little trouble sorting through those particular instructions on Flickr, so that inspired me to create the tutorial that follows below. However, Lucidlook had since created a more up-to-date tutorial (I am uncertain if he is the original author on Flickr) that can be found here. Although the steps shown below are the result of me hashing it out, I can't take credit for the original effect.

I'm a GIMP noob. Yeah, I admit it. Albeit, quickly becoming a hardcore GIMP'er and salivating over the upcoming release of version 2.8. Enough about that, let's get on with the tutorial... Let me first say, if you ever find yourself attempting a tutorial and you just "don't get it" as you're following along, or even worse - you download a script and have NO clue as to what to do with it, FRET NOT! Usually script authors will say something to the effect of "this script is based on a Photoshop tutorial, click link here..." If they do mention a tutorial, try to follow that tutorial as best you can - or  - check my sitemap on to see if I have covered it. I downloaded the Displacement Water .scm filter, followed the links offered by the author, and went over the instructions a few times. Not reading the instructions carefully makes a difference in whether you're going to succeed or fail in accomplishing the use of the script. That being said, because there was so much input on various links, it all got mixed and garbled in my mind, so I spent a few hours sorting it all out. If you don't have the Displacement Water script and want to follow along, follow the link to get it, but while you're at it, grab this mirror script by Saul Goode, too. The mirror script will save a ton of steps in doing the tutorial. Remember, this is the "noob version" of water displacement. The general purpose is to get everyone understanding how best to use it. Once you accomplish it, feel free to modify your colors or add new layer effects, etc.

The video:

(Best viewed in HD, full-screen, on YouTube)

The following image (found under Vignette script on the GIMP Registry) will be used in this tutorial, copy and paste it into GIMP:


If you haven't added the mirror-dup.scm script to GIMP, do it now. Once you refresh the scripts, you will find it under Filters/Map/Mirror on the menu bar.  You'll see this (use the same selections as shown):

You should now have an even vertically mirrored image of a frog:


Make a duplicate layer of the mirrored image.


It's time to make the water displacement map. Select Script-Fu/Map/Water Reflection map on the menu bar. You'll see the following (use the selections shown):

For my Polish friends...

Dla moich znajomych polskim: Czy próbowali za pomocą Google Translate na wychowawczy?

The original frog image was 500 x 380, so that is what x and y should be in the selections above. Remember this whenever you create new water reflections (X and Y are the width and height of your original image before you alter it). You should end up with a displacement map that looks like this:

You'll notice the name of this image is red.# and it is a separate image from your frog image. We'll be pasting this map into a new layer on the frog image.

My displacement script threw errors a few times, so if it throws an error for you, try it a few more times. If errors persist, leave a comment for the script author indicating what those errors are.  If you correctly identified the image width and height, you shouldn't have any problems.


You should have two layers on your mirrored frog image, add a new layer to the top. With the new layer highlighted, copy the displacement map (layer X) we just made and paste it into the new layer. Use the Move tool to move the displacement map over the bottom area of the mirrored image before you anchor the floating selection. When you're happy with the location, anchor the layer. Note the image below:

(TIP:  After you paste the displacement map into the new layer, you can use your arrow keys to move it sideways or up and down).


Add another new layer. Select the Rectangle Select tool. Select the bottom half of the picture with the displacement map.

Add a layer mask  (White - Full Opacity) to the new layer.

Select the Gradient tool using the default black & white gradient and drag a gradient from the halfway point to the bottom. Your layers should look like this:

Notice that there are links on the displacement map and the background copy? You need to do the same thing. All you are doing is linking the displacement map to the background copy so that when you finally map the water displacement, it will show the layers for the displacement map in the lists.

I didn't name my layers, which I should, and you should make a practice to name your layers as well.


Select and highlight the background copy layer just under the displacement map, and go to Filters/Map/Displace. Note the selections in the image below:

For small image reflections like this one, the only way to utilize an X displacement is to make your image selection area wider. Otherwise, you'll have to leave it at zero to avoid it leaving blank areas in your reflection area. (Check the preview when adding X displacement, you'll see what I mean). Y displacement is usually twice the displacement of X. We'll make an exception here. :)

To see the result of what the displacement achieved, click the eye on the displacement layer to off.


Adding color is fairly simple, just remember two things:  1) Create a selection for the lower half of the image when using colored gradients, and 2) the sky is the limit on color choices or blend effects.

Select and highlight the top most layer (with layer mask), link it to the displacement map and background copy, then select the bottom half of the image using the Rectangle Select tool, if it's not already selected.

Select the Gradient tool, and pick a darker emerald green color and a lighter shade of emerald green. See my color choices below:

Drag the Gradient tool down from the halfway point to the bottom. You can reduce the transparency, if needed. That's it, you're done!

The final product:


Friday, September 4, 2009

GIMP: Changing Colors In An Image - Quick and Easy.

I've read about changing colors in comments somewhere on a tutorial site, but I have yet to find the tutorial that explains how its done. So I did a little digging and discovered just how easy it is to do. Perhaps everyone already knows how to do this and I am just a late bloomer in GIMP. If you have no idea of what I am talking about, follow along.

For testing purposes, I grabbed a picture off Google Images of a purple shirt.

This was simple enough. If you want to grab this photo to test with, be my guest and (right click the image and save as or copy/paste into Gimp) grab it.

Step 1:

I assume you have GIMP already opened and the picture above pasted or opened. Go to Colors - Hue Saturation:

You'll see this:

Looking at the purple shirt, we notice there is more blue than red or magenta (funky purple color). So you will select the "B" radio button and give it a tick.

Start moving the Hue slider to your desired color.

I've tried using Overlap and it didn't produce any results, that I could notice. The reason for that is because (according to the GIMP manual) this slider lets you set how much color ranges will overlap. This effect is very subtle and works on very next colors only. (Click here for more information.)
You can lighten or darken your color choice with the lightness slider. (Keep in mind that using the darker end of this slider could result in color blotches showing on your drawing, to avoid this, go to Select - Color select, and begin selecting the colors in the shirt while holding the Shift key until most all the colors of the shirt are selected, before using Hue-Saturation. I have had good success dragging my cursor through the shirt colors.) * The idea is to only get the shirt area selected and NOT the shaded areas (drop shadows)*

You can select the richness of the color by using the Saturation slider.

If you screw up, click reset and start all over. Make sure preview is ticked so you can see the results on the image.

Step 2:

Click "OK" to save the selection to your image.

That's it, you're done. (If you don't like the resutls, CTRL + Z and start all over.)

Step 3: (For more involved images with lots of similar colors)

What if you had a picture of 3 or 4 people and two people were wearing the same shirt color, but you only wanted to change one shirt color and not both? The method for doing this is very simple:

Isolate the part of the image with the color you want changed by using the Free Select tool. Note: you don't have to follow the colored item perfectly, just put a selection around it so the Hue -Saturation filter knows you only want that selected area changed. Otherwise, if you don't, when selecting the color to change, ALL colors similar to your selected choice within the image will change. See the image below for an example of what I mean:

Had I not selected the sleeve area, the entire shirt would have changed to the green color.

You could even use this technique to add stripes or patterns to clothing.  But if you decide to do this, you need to select antialiasing AND add about a 3 - 5px feather to the Free Select tool in the tool options dialog. If you don't, your selection will leave you with some jagged looking lines in the image.

The shirt result with antiliasing and feather edges (5px) selected:

This technique could come in handy if you wanted to show support for your favorite team by changing the colors in your image to that of the team's colors.


Just remember that for this to be effective, pick the closest primary color to the color in the image you want changed. If several areas in the image share the same primary color, then isolate what you want changed by placing a selection around it before using Colors  -  Hue-Saturation.

A little something I did in support of the Kansas City Chiefs:

Have fun! :)

Wednesday, September 2, 2009

GIMP: Ultimate GIMP Planet Tutorial

I was back to seeking out new GIMP tutorials (sort of saving the longer/harder tutorials for last) but surprisingly, this particular tutorial was long, but NOT hard to follow, at all. It involves Planet rendering, includes a modified render script to update GIMP with, and direct links to all the materials, textures, etc. You can find that tutorial here. I was pleasantly surprised to discover it to be relatively straightforward. My goal in doing this tutorial was to make a mock poster to play a joke on a good friend of mine, (Teggy R). I hope he understands my sense of humor and doesn't take offense. :) First, this is the result of my following along with the tutorial: 

The only thing I did differently was, I added effects from the SpaceScape script, to give the background a little bit of an extra galactic cloud look. The SpaceScape script can be found here
The joke I was aiming for, and the reason I followed the tutorial: 
(Beware of the NOOBS!)