tlog (Posts about gimp)

Walkthrough for a simple photo post-process

Thibauld Nion — Mon, 12 Oct 2009 00:04:07 GMT

When posting one of my pictures, I usually say that some post-processing was done. This is nothing but very classical stuff, that I believe are common to most photographers. However I've been advised to give a glimpse of what those modifications were. And that's why this post will explain and illustrate, for a very simple case, how, starting with a picture coming out of my camera, I get one that suits me enough to post it here. The picture I'll use as an example is the following: Long story short, the post process I usually do, and that I will show here have basically two purposes:

improve color and contrast
re-frame the picture

Some more flowers: post-processing

Thibauld Nion — Sun, 26 Jul 2009 12:44:50 GMT

I've started to go through some of the photos from my Printemps gallery that were post-processed too hastily...

The first image, that I've tried to fix is the one below, with a single flower whose petals are too weakly colored in the original shot.

: Original shot

The image that made its way to my gallery suffers from over-saturation, because I only applied global changes on the white balance and the overall contrast, which was probably not well suited here (or at least not enough).

: Flower with overly saturated colors.

To get a better result (with Gimp), the easiest way is to use the layers and layer masks. This technique is well explained in the MeetTheGimp[en] podcast (for instance in the latest episode[en]).

: A layer mask isolating the flower.

So layers make it possible to work with several images superimposed, and to control the transparency effects ((ie how much the top image will mask the images underneath)). Here, only two layers were needed: a image of the origianl shot, modified in order to make the greenish background darker and an image of the same shot but where the colors and luminosity have been enhanced. Using a layer mask on this second image, made it possible to keep the modifications only on the white regions of the mask. Thus, I could modify the color of the flower independently from the background. Images below show three examples of such modifications.

Gimp recherche des développeurs

Thibauld Nion — Fri, 18 Jul 2008 22:40:39 GMT

Certains plugins de Gimp sont orphelin (ou sur le point de l'être) et le projet recherche des développeurs si vous êtes susceptibles d'aider lisez l'annonce ci-dessous. (je relaie le message posté sur le blog MeetTheGimp que je re-recommande d'ailleurs vivement à qui est intéressé par la photo et/ou Gimp)

For the very cool Gimp Colorize Plugin Christopher Lais is looking for a new maintainer. Don't let this die. The same is about the quite good GREYCstoration plugin, volunteers wanted to improve the code of the current GIMP plug-in and implement features of the commandline version. The third is the JPG2000 plugin, since the GSoC project nothing happens and nobody has seen this working in Gimp on Linux. So new developers are needed to improve existing plugins and move them to Gimp 2.4 and later to 2.6. Anybody reading this could help finding the new maintainers and developers. Post this on your blog and your related boards! If one of your friends could do this ask him!