LinuxPhoto.org
The place for all photography and linux fans
-
licence: closed source, freeware, donations are welcome
-
dependencies: GTK+ 2.10
-
about:
Raw Therapee is a one man project with an interesting set of features. It uses DCRaw for decoding RAW files and rendering colors, but one of two of its own demosaicing algorithms (HPHD or EAHD). This is the most interesing part of this application as both of them are really great, giving nearly artifact-free images. Raw Therapee is nearly completed but could use some improvements (lack of batch processing, channel mixer etc.).
Source code is NOT available but installation is very easy. Just download the program and unpack to destination folder.
-
GUI and workflow:
Raw Therapee has a very simple and well defined GUI. No separate browser and editor, nor post processing steps known from DxO optics or Raw Magick. Interface you see at the start is everything the program has. There is history panel on the left, and image browser at the bottom. Both can be hidden. Histogram and tools are on the right, and that's it. No IPTC, simple EXIF support (Raw Therapee copy exif data into created files (not true for Canon), but shows only few of them during processing), no photo management nor printing. It is a pure developer that leaves selective editing, managing and publishing/printing to other applications. Unfortunately there is no batch processing so working on large number of files is difficult. The only way to do it is to save a custom profile and then apply it to other images, one by one. Default profile may also be helpfull as it can be changed. All processing settings are saved as .pp2 files created in the same folder as original image (like .bib files from Bibble).
Zooming is quite interesting but frustrating for most of the users. Instead of explaining how it works I'd rather tell how to use it. "Detail" shows a small crop of the image in 1:1 or higher magnification, while main zoom is to set the size of "fit to screen" preview. Set it to 100% and then set "scale" factor to see whole image. This is not a simple zoom, it reduces resolution of the preview making it faster to process (and you can still see the real 1:1 zoom in crop window). This is a great feature, when you know how it works, and a big drawback if you consider it as an ordinary zoom option.
Raw Therapee supports nearly all RAW formats as well as jpg, tiff and png (those two are supported in 8 and 16 bit modes).
-
processing images:
Raw Therapee is designed to give sharp, noiseless images with proper contrast and general tonality, therefore there is lack of color manipulation tools (hue, saturation and others). We all should remember that this is free software developed and maintained by one guy so lack of many features is quite obvious. Existing tools are very well explained at projects website and there is no point in explaining it here once again. Still I suggest reading the website carefully because some small differences between tools are explained there. In fact I thought that half of the tools is implemented twice before I red the manual.
The strongest part of Raw Therapee is it's highlight recovery (there are two methods - "luminance recovery", and "color propagation") and demosaicing method. Those algorithms are really professional and many commercial companies does not give it's customers nothing comparable (see this tests to see how various RT algorithms are performing). Extraordinary control over sharpening, contrast and general tonality is another strong part of the software (well, I dont like "shadows/highlights" tools as it gives very strong halo around edges). Another nice feature is chromatic aberration correction (not very common tool), and (very) basic distortion correction. The last one is maybe not the greatest, as it gives nearly no control over distortion characteristics, but it surely helps. Lack of BW conversion and some basic color manipulation tools (hue, saturation) is evident and it's the biggest problem, but smart users can use "color boost" and "color shift" to simulate what they need (for example reduceing A, and B channel to 0 gives desaturated image). If someone does not need to retouch colors and has fast CPU (as some tools are slow) Raw Therapee is a great piece of software.
-
known problems: Remember that Raw Therapee does not create folder with settings in your home directory but saves everything in its own. Therefore installing it in /usr/share is not the best option if you don't have write permissions there (still program works, user just need to save profiles somewhere else). Another problem is speed (remember the zooming?).
-
conclusions: Raw Therapee is a very interesting alternative for advanced amateurs processing color images in small number, or as a part of bigger worflow (as RAW developer).