Download the Video!
Download the companion file! (…if there is one…. 
)
Today we are going into Math-Land, but not too deep – I promise. But first there is a visit to the Oakland Technology Exchange West – a non profit that gives new life to (not so) old hardware.
The Convolution Matrix lives in Math-Land. It is the backbone of a lot of filter plugins. It’s fun to play with if you have understood the basics and lost your fear. One example of a filter done with this is the Pencil Shade Filter by Alex Turner
I forgot to talk about the “Border” options. “Extend” just adds a virtual black border around the source image. “Wrap” takes the pixels from the opposite corner and wraps them around.
The matrix in the image has no deeper meaning, it’s just some random numbers.
My lens replacement surgery went well and I am recovering fast. Thanks for all the good wishes!
The TOC
00:19 Welcome
00:23 Oakland Technology Exchange West
02:25 Rolf’s Eyes
03:13 Convolution Matrix Filter
05:18 – User interface
06:08 – Experimenting
06:56 – The documentation
12:30 – sharpening
16:48 – blur
17:16 – normalize option
18:02 – edge enhance
21:38 The End
TOC made by paynekj
This work is licensed under a
Creative Commons Attribution-Share Alike 2.0 Germany License.
Very interesting, the mind boggles at the endless possibilities.
Yes, my brain still wobbles.
I need paper and pencil to understand some of the stuff – sharpening for example.
Hello Rolf,
Good to hear that your recovery from the eye surgery is going well!
I just wanted to thank you for mentioning our organization, Oakland Technology Exchange West, in this week’s episode. If anyone in your audience is interested in donating a computer, a good directory can be found at http://www.techsoup.org/servicedirectory/index.cfm . This is mainly for the US and Canada. Of course, anyone in the San Francisco/Oakland area knows where to go now
Nice to hear about your post-surgery recovery, Rolf.
Cheers
Convolution matrix filter is as interesting as it is irritating for one simple reason: huge possibilities and the absence of any reasonable way of saving the settings for future use (unless you take a pencil and put all the numbers manually down).
Part of the FX Foundry script package is a huge convolution presets script; worked fine with 2.4, but doesn’t work with 2.6
Another fine and interesting video from MTG!!
Thanks!!
Jeff.
Correction to my above post. The fx-foundry preset script works with 2.6.x, you can find it here http://gimpfx-foundry.svn.sourceforge.net/viewvc/gimpfx-foundry/gimp-2.6/stable/ , the name is iccii-convolution-presets.scm; a good demonstration of the possibilities you have with this math thing.
Thanks for bringing this up — I’ve had a look at it in Photoshop long ago, but I’ll absolutely have to experiment with it in the GIMP now.
Best wishes
/ Mats
Pingback: Цифровая фотография - » MTG: Обзоры выпусков за весь 2008 год!
Pingback: Episode 188: The Book | Meet the GIMP!