Episode 164: High Pass Sharpening

Download the Video! (16:13 30.9 MB)
Download the companion file! (49.0 MB)
Download the torrent file!
[flattr /]

Sharpening is a part of nearly every image processing. Selective sharpening allows to sharpen the important structures without to “enhance” the noise in the image. Already in Episode 6 I have shown a way to do this. And here is another way, High Pass Sharpening. It is often used in Photoshop tutorials and has no standard entry in the GIMP menus.

One step involves blurring – and this leads to a lot of different possibilities to change the effect. I explore asymmetric sharpening by blurring only into one direction.

Of course there are plugins available at the GIMP plugin registry.

A description of several sharpening methods is in our Wiki, I’ll add the high pass method today.

I got the recipe for this from a (very good) German book by Jürgen Wolf.

The TOC

01:48 Good German book: Jürgen Wolf, GIMP 2.6
02:00 GIMP 2.8 release late in 2011!
02:20 Preparing the image
02:40 Rotate
03:30 Crop
04:10 Contrast, black point and white point adjustment with the curves tool
05:30 The recipe for Highpass Sharpening
05:40 Duplicate the layer twice
05:50 Invert the colours
06:00 Set layer mode to Grain Merge
06:10 Blurring
07:00 Merge the top layer down and set the layer mode to Overlay
07:50 Adjusting the effect with the opacity of the sharpening layer
08:00 Sharpening in only one direction
09:50 What is Grain Merge doing?
11:00 How does this work?
14:50 Scripts at the http://registry.gimp.org

Creative Commons License
Meet the GIMP Video Podcast by Rolf Steinort and Philippe Demartin is licensed under a Creative Commons Attribution-Share Alike 3.0 Germany License.
Permissions beyond the scope of this license may be available at http://meetthegimp.org.

Epsiode 117: Digital GND?

Image by Ray Adagio
Download the HD-Video! (32.7 MB, 17:12)
Download the Video for iPods etc (23.8 MB, 17:12)

This week I show you how to simulate a Graduated Neutral Density Filter with GIMP. This was started by a thread in the forum. And as I now need more time between recording and publishing, the thread has grown considerably and Bert has already made a script for this. So check it out in the forum!

While trying to create a filter for the image I stole from Bert I tell you a bit about the Blend Tool and give (again) an introduction into layer masks. “White reveals and black conceals!” 😉

If you are a Linux Geek living in the UK, you may be tempted to attend the Ogg Camp, organized by the Ubuntu UK Podcast and Linux Outlaws.

Creative Commons License
Meet the GIMP Video Podcast by Rolf Steinort and Philippe Demartin is licensed under a Creative Commons Attribution-Share Alike 3.0 Germany License.
Permissions beyond the scope of this license may be available at http://meetthegimp.org.