Meet the GIMP!

Please read the comments - some important stuff may have shown up!

Linux - with GUI

Check that the packet gimp-python is installed.

Copy your .py file into the directory .gimp2.4/plug-ins . This is a hidden directory, you don’t see it in the file browser. With Nautilus you can toggle the display of the hidden files with Ctrl-H.

Then make the file executable by right clicking, selecting “Properties” from the menue and activate “Execute” in the permissions tab.

If GIMP was running, restart it.

Linux - with commandline

Check (with synaptic) that the packet gimp-python is installed.

Enter this:

cp myfile.py ~/.gimp2.4/plug-ins
chmod u+x ~/.gimp2.4/plug-ins/myfile.py

If GIMP was running, restart it.

Mac OS

Please write an instruction into the comments - I’ll pull it up to here.

Look through the comments for a solution - but I think there must be a better one.

Windows

Copy the files to ~/.gimp2.4/plug-ins

With the following prerequisites:

- PyGTK, PyCairo and PyGobject (all available from the GNOME FTP mirrors as installers) are installed prior to installing GIMP
- ~ is %USERPROFILE%

If GIMP was running, restart it.

 Podcast Video (38.2 MB): [28:19m]: Play in Popup | Download (7919)
 Torrent: Download (320)
 The image as XCF file and the script: Download (394)

Finally the “Zone Adjustment Plugin” - formerly known as “Meaningful Black Script” is shown in its full glory. You find it here and in the companion file.

And I present a plugin for displaying EXIF information in an image, a split toning plugin and a plugin for applying the “Lazlo Dragan effect”. (Download should now be possible without need to register - sorry, made a mistake in the configuration.) All were published in the Forum of Meet the GIMP.

You can find information about the installation of these plugins there too. Basically you just copy them into your plugin directory (not the scripts directory) and make them executable. The last step is not necessary under Windows.

The show starts with a short introduction into the Zone System of Ansel Adams. Before we go deeper into this, we have to calibrate our cameras. Set your camera to manual mode, set the metering to spot or center based and shot a well exposed image of something middle grey or whitish with a bit of structure in it. I took a white door, but raw concrete is fine too. Then shoot two series of images, the first one closing down one stop in each image, the other in opening up one stop for each step. We’ll look at my images next week.

The TOC:

Ansel Adams and the Zone System 0:27
Calibrating your camera for the Zone System 7:00
Plugins in the Forum 9:36
Working with the “Zone Adjustment Plugin”, formerly know as “meaningful Black” 11:25
Detaching menues in GIMP 12:23
Sample Points 12:50
Finding the Dark and Bright point 15:25
Using the plugint 19:40
The proof: white is grey - and black too! 25:25

The image used in this podcast was made during a performance of Pascale Loiseau from the Belgian  WAZOVOL artists group. I found a video of her performance.

Edit: I changed “script” to plugin - there is a bit of confusion….

This work is licensed under a
Creative Commons Attribution-Share Alike 2.0 Germany License.

 Podcast Video (48.1 MB) [36:10m]: Download (10128)
 Torrent: Play in Popup | Download (143)
 Python source code: Play in Popup | Download (105)

Will this title scare more people away than catch by curiosity? Who knows…..

The barrel distortion that gave me such problems last week is removed by using a built in filter for correcting (or simulating) lens distortions. You can find it in the image menu at Filters/Distorts/Lens Distortion.

As I have a lot of images with this error, I go out and write a special Python plugin to do this task. It’s not as complicated as it seems - I have a good template and the Web and Gimp give a lot of useful information. You can find the scripts used in this episode here on the Download Page

EDIT: If you are using Windows and GIMP 2.4.x, have a look here for informations about setting up Python for GIMP.
EDIT2: This is supposed to be even easier.

This is the finished Python program:

#!/usr/bin/env python

import math
from gimpfu import *

def remove_barrel_distortion(img, drw):

img.disable_undo()

layer_corr = drw.copy(True)
layer_corr.mode = NORMAL_MODE
layer_corr.name = "Barrel corrected"
img.add_layer(layer_corr, -1)

pdb.plug_in_lens_distortion(img, layer_corr, 0.0, 0.0, -12.0, 0.0, 0.0, 0.0)

img.enable_undo()
gimp.displays_flush

register(
"remove_barrel_distortion",
"Removes the barrel distortion of a Sanyo CA65",
"",
"Rolf Steinort <info @meetgimp.org>",
"public domain",
"2008",
"<image>/Filters/Distorts/B_arrel distortion removal CA65",
"RGB*, GRAY*",
[],
[],
remove_barrel_distortion)

main()


You find a similar program in this posting. There I have torn it apart and described all the parts. The Python for GIMP documentation and this website can be helpful.

Don’t forget the challenge! Make a monochrome image and post it in our meetthegimp.org photogroup at 23 and be sure to use the tag “mtg-monochrome”. The challenge ends March 31 1600GMT and I’ll draw a winner by random choice.

Contact me!

You can leave your comments on this blog or write me a mail.

The TOC

00:23 Update from the last episode
01:50 Lens Distortion
06:02 Comments on the blog
08:47 Programming in Python
09:40 - Discussion on the blog
10:56 - Explaining the Python program
20:33 - Procedure browser
25:31 - Parameters
27:35 - Error messages
29:30 - Adding a new layer
32:33 - Summary
34:01 “23″ image hosting
36:09 The End
TOC made by paynekj

This work is licensed under a
Creative Commons Attribution-Share Alike 2.0 Germany License.