RawTherapee 3.0 alpha 1 and license changes

The first alpha version of RawTherapee 3.0 is available for download. Note that this is not a feature complete version. In V3.0 both major
GUI/workflow and algorithm changes are planned. This alpha version demonstrates the new, much more efficient GUI, but it does not contain
any algorithmic changes yet.

The most significant changes in the GUI are the following:

  • multi-tab interface
  • the real batch processing support arrived: select multiple images and adjust them together (the multi-adjust behavior of some parameters is selectable in the preferences dialog: they can be either additive or absolute)
  • completely re-written editor: preview and detail view are now gone. The main image view can be magnified as required, and only the necessary part of the image will be re-calculated. There is a small navigator, too, and infinitely many detailed views can be opened to investigate fine details.
  • 16 bit thumbnails (an option, takes double disk space)
  • before/after view in the editor

The only change in the algorithms is:

  • the behavior of the exposure controls changed. The “exposure” parameter is what was called “brightness” in previous versions. The “brightness” parameter is now a real brightness control, that shifts the histogram (of course with highlight/shadow protection)

Roadmap of algorithm changes planned for V3.0 (approximately in sequence of implementation):

  • new curve editor with parametric curve support
  • per-image selectable demosaicing method + brand new demosaicing methods
  • new color denoising method
  • new luminance denoising method
  • automatic C/A correction
  • purple fringing correction
  • perspective correction
  • bad pixel removal

License changes:

I decided to change the license to GPL and thus offer the source code to the open source community. This does not mean that I stop developing RawTherapee. I will invest as much time into the development as till now. I have three motivations for this decision: first, I love playing with image processing algorithms but I’m not keen on GUI development. Recently a huge amount of work had to be invested to develop a usable GUI and I had no time left to play with new algorithms. I hope to involve some new developers who help me to maintain and enhance the GUI. The second reason of licence change was that I am very frustrated by the huge amount of bug reports I can not reproduce (believe it or not, RT is stable on my PC). I hope that with the open source model some talented users can identify the problems and fix the bugs. The third (but maybe the most important) reason of switching to GPL is that our baby reached the age (10 month old) when he needs his father more and more. I dont want to disappoint him :). With more developers involved the development process will hopefully more smooth and wont stop when I am busy.

Some technical details for future developers:

  • The SVN and issue tracker is maintained by google code here
  • The development discussions are running on the forum
  • Patches are to be sent to: patches at rawtherapee dot com
  • RawTherapee consists of the following 3 parts: rtexif: the exif/makernote support library. It is quite complete and works well. It needs continuous maintenance, for which I have too few time. The maintenance means to maintain the exif and makernote tag interpretation tables (to follow newest cameras, lenses, etc), for example based on the excellent informations found here.
  • rtengine: this is the image processing library. It has a quite clear calling interface, but the code behind is a bit messy right now, since I am in the middle of a cleanup. If there will be several developers involved in the project, I would prefer to keep the maintenance of rtengine in my hands. The development of this part is what I enjoy the most.
  • rtgui: the graphical user interface. This is a very important part of RT. If there were enough developers involved, I would be happy to hand over the coordination of this part to someone else. Of course, I will maintain it, too, if there are no volunteers.

I need help to improve the build system, too (but I want to stick with cmake – autotools is painfully slow on windows)

Hardcore linux coders: please accept that windows is a primary platform. (I use a linux environment for development, too, but the vast majority of downloads was the windows version)