Raw Therapee
Encyclopedia
RawTherapee is a cross-platform
raw image processing
application, recently released under the GPLv3. It is written in C++
using a GTK+
front-end
and dcraw
by Gábor Horváth of Budapest
, Hungary
. It is notable in that it was one of the first raw converters available for Linux with a reasonably usable GUI, and for the control it gives the user over the demosaicing
process. The name used to stand for "The Experimental Raw Photo Editor", however that acronym has been dropped, and RawTherapee is now a full name in itself.
All the internal processing is done in 16 bits/channel color resolution.
While reading raw files it relies on the dcraw
code, but only for parsing formats, not for processing. Thus, RawTherapee supports all the formats supported by dcraw.
Additionally, RawTherapee supports the following image formats:
While the image is opened for editing, the user is provided with a preview window with pan and zoom capabilities. A color histogram is also present offering linear and logarithmic scales, and separate R, G, B and L channels. All adjustments are reflected in the history queue and the user can revert any of the changes at any time. There is also the possibility of taking multiple snapshots of the history queue, allowing for various versions of the image being shown, however these snapshots are not written to the sidecar file
and are subsequently lost once the photo has been closed.
PP3 files of the current alpha version might not be compatible with the final 3.0 version, but users are encouraged to try the latest version as it has had a complete code overhaul since version 2.4.1 and offers many new features. Extensive testing and reporting bugs in the RawTherapee forum or on the RawTherapee Google Code page will help the development team in releasing a more stable final version.
This version incorporates some major changes:
Because of the higher RAM requirements the 4.0 version is still released for 32bit operating systems, but 64bit versions are highly recommended for stability.
Cross-platform
In computing, cross-platform, or multi-platform, is an attribute conferred to computer software or computing methods and concepts that are implemented and inter-operate on multiple computer platforms...
raw image processing
RAW image format
A camera raw image file contains minimally processed data from the image sensor of either a digital camera, image scanner, or motion picture film scanner. Raw files are so named because they are not yet processed and therefore are not ready to be printed or edited with a bitmap graphics editor...
application, recently released under the GPLv3. It is written in C++
C++
C++ is a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as an intermediate-level language, as it comprises a combination of both high-level and low-level language features. It was developed by Bjarne Stroustrup starting in 1979 at Bell...
using a GTK+
GTK+
GTK+ is a cross-platform widget toolkit for creating graphical user interfaces. It is licensed under the terms of the GNU LGPL, allowing both free and proprietary software to use it. It is one of the most popular toolkits for the X Window System, along with Qt.The name GTK+ originates from GTK;...
front-end
Front-end and back-end
Front end and back end are generalized terms that refer to the initial and the end stages of a process. The front end is responsible for collecting input in various forms from the user and processing it to conform to a specification the back end can use...
and dcraw
Dcraw
dcraw is an open-source computer program which is able to read numerous raw image formats, typically produced by high-end digital cameras. dcraw converts these images into the standard PPM and TIFF image formats...
by Gábor Horváth of Budapest
Budapest
Budapest is the capital of Hungary. As the largest city of Hungary, it is the country's principal political, cultural, commercial, industrial, and transportation centre. In 2011, Budapest had 1,733,685 inhabitants, down from its 1989 peak of 2,113,645 due to suburbanization. The Budapest Commuter...
, Hungary
Hungary
Hungary , officially the Republic of Hungary , is a landlocked country in Central Europe. It is situated in the Carpathian Basin and is bordered by Slovakia to the north, Ukraine and Romania to the east, Serbia and Croatia to the south, Slovenia to the southwest and Austria to the west. The...
. It is notable in that it was one of the first raw converters available for Linux with a reasonably usable GUI, and for the control it gives the user over the demosaicing
Demosaicing
A demosaicing algorithm is a digital image process used to reconstruct a full color image from the incomplete color samples output from an image sensor overlaid with a color filter array...
process. The name used to stand for "The Experimental Raw Photo Editor", however that acronym has been dropped, and RawTherapee is now a full name in itself.
Features
RawTherapee involves the concept of non-destructive editing, similar to that of some other raw conversion software. Adjustments made by a user are not applied immediately to the image, but the parameters are saved to a separate settings file (however, the user can see all effects of adjustments in the preview window). Actual adjustments to image are made during the export (or 'save' in terms of RawTherapee) process.All the internal processing is done in 16 bits/channel color resolution.
Input file formats
RawTherapee can work with both raw files from digital cameras and usual images.While reading raw files it relies on the dcraw
Dcraw
dcraw is an open-source computer program which is able to read numerous raw image formats, typically produced by high-end digital cameras. dcraw converts these images into the standard PPM and TIFF image formats...
code, but only for parsing formats, not for processing. Thus, RawTherapee supports all the formats supported by dcraw.
Additionally, RawTherapee supports the following image formats:
- JPEGJPEGIn computing, JPEG . The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality....
- TIFFTagged Image File FormatTIFF is a file format for storing images, popular among graphic artists, the publishing industry, and both amateur and professional photographers in general. As of 2009, it is under the control of Adobe Systems...
- PNG
User interface
RawTherapee provides the user with a file browser, which shows thumbnails of images along with brief shooting info. The browser includes 5-star rating, flagging, and an EXIF-based filter.While the image is opened for editing, the user is provided with a preview window with pan and zoom capabilities. A color histogram is also present offering linear and logarithmic scales, and separate R, G, B and L channels. All adjustments are reflected in the history queue and the user can revert any of the changes at any time. There is also the possibility of taking multiple snapshots of the history queue, allowing for various versions of the image being shown, however these snapshots are not written to the sidecar file
Sidecar file
Sidecar files, also known as buddy files or connected files, are files which store data which is not supported by the source file format.For each source file one or more sidecar files can be created...
and are subsequently lost once the photo has been closed.
Adjustment tools and processing
- DemosaicingDemosaicingA demosaicing algorithm is a digital image process used to reconstruct a full color image from the incomplete color samples output from an image sensor overlaid with a color filter array...
. User can choose from EAHD, HPHD, VNG-4, DCB, AMaZE, AHD, fast and bilinear algorithms. - Processing profiles support with the ability to load, save and copy profiles between images.
- Exposure control allowing manipulation of exposure compensation, brightness, highlight recovery, shadow recovery, brightness, contrast and saturation.
- Advanced highlight reconstruction algorithms and shadow/highlight controls.
- RGB and Lab curves
- Various methods of sharpening
- Various methods of noise reductionNoise reductionNoise reduction is the process of removing noise from a signal.All recording devices, both analogue or digital, have traits which make them susceptible to noise...
- Detail recovery
- White balance (presets, color temperature, spot white balance and auto white balance)
- Channel mixer
- Color boost (saturation control)
- Hue, saturation and value adjustments on eight separate colors
- ICC Color profiles (input, working and output)
- Crop
- Resize
- Rotation with visual straightening tool
- Distortion correction
- Perspective adjustmentPerspective controlPerspective control is a procedure for composing or editing photographs to better conform with the commonly accepted distortions in constructed perspective. The control would:...
- Manual and automatic chromatic aberrationChromatic aberrationIn optics, chromatic aberration is a type of distortion in which there is a failure of a lens to focus all colors to the same convergence point. It occurs because lenses have a different refractive index for different wavelengths of light...
correction - VignettingVignettingIn photography and optics, vignetting is a reduction of an image's brightness or saturation at the periphery compared to the image center. The word vignette, from the same root as vine, originally referred to a decorative border in a book. Later, the word came to be used for a photographic...
correction with adjustable center offset - Dark frame subtraction
- Hot and dead pixel filter
- Metadata (EXIF and IPTC) editor
- Processing queue
Output formats
Output format can be selected from:- TIFF (8 and 16 bit)
- JPEG (8 bit)
- PNG (8 and 16 bit)
2.4 series
The latest version marked as stable was 2.4.1 released in September 2009. Since then RawTherapee has become open source (it was closed before 2010) and a number of developers have joined the project. As a result of this, version 2.4.1 is very outdated, and although the latest builds offer numerous new features, they are not officially marked as stable, although numerous users have reported that some branches of the program are stable under Linux and Mac. The Windows builds are more prone to crashes.3.0 series
This new series is now on the development cycle. Currently version 3.0 alpha 2 is feature frozen and undergoing stabilization. It is not production ready yet, as the sidecar fileSidecar file
Sidecar files, also known as buddy files or connected files, are files which store data which is not supported by the source file format.For each source file one or more sidecar files can be created...
PP3 files of the current alpha version might not be compatible with the final 3.0 version, but users are encouraged to try the latest version as it has had a complete code overhaul since version 2.4.1 and offers many new features. Extensive testing and reporting bugs in the RawTherapee forum or on the RawTherapee Google Code page will help the development team in releasing a more stable final version.
This version incorporates some major changes:
- New licensing: RawTherapee is now released under the GPL licence.
- New interface layouts possible offering more efficient screen space usage. Separate file browser and processing queue tabs. A choice between "single tab filmstrip mode" and "multiple tab mode", both with the possibility of having the tabs positioned vertically.
- Ability to open multiple images simultaneously.
- New preview logic. Faster and smoother zooming and panning. Smoother preview image.
- Numerous new filters and demosaicingDemosaicingA demosaicing algorithm is a digital image process used to reconstruct a full color image from the incomplete color samples output from an image sensor overlaid with a color filter array...
algorithms.
4.0 series (formerly 3.1)
This new version is the most actively developed version. It incorporates some major changes:- New engine, all processing takes place in floating point for high precision
- UI is improved and more customizable
- New image processing tools, like black point compensation, new highlight recovery methods, automatic distortion control on four thirds cameras, flat field correction
- Improved color management
- Stability enhancements (however some only on Windows, not back ported to other platforms yet)
Because of the higher RAM requirements the 4.0 version is still released for 32bit operating systems, but 64bit versions are highly recommended for stability.