RawTherapee is

application software Application may refer to: Mathematics and computing * Application software, computer software designed to help the user to perform specific tasks ** Application layer, an abstraction layer that specifies protocols and interface methods used in a c ...

for processing photographs in

raw image format A camera raw image file contains unprocessed or minimally processed data from the image sensor of either a digital camera, a motion picture film scanner, or other image scanner. Raw files are named so because they are not yet processed and the ...

s, as created by many digital cameras. It comprises a subset of

image editing Image editing encompasses the processes of altering images, whether they are digital photographs, traditional photo-chemical photographs, or illustrations. Traditional analog image editing is known as photo retouching, using tools such a ...

operations specifically aimed at non-destructive

post-production Post-production is part of the process of filmmaking, video production, audio production, and photography. Post-production includes all stages of production occurring after principal photography or recording individual program segments. The ...

of raw photos and is primarily focused on improving a photographer's workflow by facilitating the handling of large numbers of images. It is notable for the advanced control it gives the user over the

demosaicing A demosaicing (also de-mosaicing, demosaicking or debayering) 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 (CFA). It is ...

and developing process. It is

cross-platform In computing, cross-platform software (also called multi-platform software, platform-agnostic software, or platform-independent software) is computer software that is designed to work in several computing platforms. Some cross-platform software r ...

, with versions for Microsoft Windows, macOS and Linux. RawTherapee was originally written by Gábor Horváth of Budapest, Hungary, and was re-licensed as

free and open-source software Free and open-source software (FOSS) is a term used to refer to groups of software consisting of both free software and open-source software where anyone is freely licensed to use, copy, study, and change the software in any way, and the source ...

under the

GNU General Public License Version 3 The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general u ...

in January 2010. It is written in

C++ C++ (pronounced "C plus plus") is a high-level general-purpose programming language created by Danish computer scientist Bjarne Stroustrup as an extension of the C programming language, or "C with Classes". The language has expanded significan ...

, using a

GTK+ GTK (formerly GIMP ToolKit and GTK+) is a free and open-source cross-platform widget toolkit for creating graphical user interfaces (GUIs). It is licensed under the terms of the GNU Lesser General Public License, allowing both free and proprie ...

front-end and a patched version of

dcraw dcraw is an open-source computer program which is able to read numerous raw image format files, typically produced by mid-range and high-end digital cameras. dcraw converts these images into the standard TIFF and PPM image formats. This con ...

for reading raw files. The name "Therapee" was originally an acronym derived from "The Experimental Raw Photo Editor".

Features

RawTherapee involves the concept of non-destructive editing, similar to that of some other raw conversion software. Adjustments made by the user are immediately reflected in the preview image, though they are not physically applied to the opened image but the parameters are saved to a separate

sidecar file Sidecar files, also known as buddy files or connected files, are computer files that store data (often metadata) which is not supported by the format of a source file. There may be one or more sidecar files for each source file. There may also be ...

. These adjustments are then applied during the export process. All the internal processing is done in a high precision 32-bit floating point engine.

Input file formats

RawTherapee supports most raw formats, including Pentax Pixel Shift, Canon Dual-Pixel, and those from Foveon and X-Trans sensors. It also supports common non-raw image formats like

JPEG JPEG ( ) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and imag ...

, PNG and

TIFF Tag Image File Format, abbreviated TIFF or TIF, is an image file format for storing raster graphics images, popular among graphic artists, the publishing industry, and photographers. TIFF is widely supported by scanning, faxing, word processin ...

as well as high dynamic range, 16/24/32-bit raw DNG images. RawTherapee uses a patched version of

code to read and parse raw formats, with additional tweaks and constraints to parameters such as white levels and the raw crop area based on in-house measurements. Thus, RawTherapee supports all the formats supported by dcraw.

User interface

RawTherapee provides the user with a file browser, a queue, a panel for batch image adjustments, a 1:1 preview of the embedded JPEG image in the case of raw files, and an image editing tab. The file browser shows photo thumbnails along with a caption of the shooting information metadata. The browser includes 5-star rating, flagging, and an

Exif Exchangeable image file format (officially Exif, according to JEIDA/JEITA/CIPA specifications) is a standard that specifies formats for images, sound, and ancillary tags used by digital cameras (including smartphones), scanners and other system ...

-based filter. It can be used to apply a profile, or parts of a profile, to a whole selection of photos in one operation. A toolbox alongside the file browser allows for batch image adjustments. The queue tab allows one to put exporting photos on hold until done adjusting them in the Editor, so that the CPU is fully available to the user while tweaking a photo, instead of processing photos while the user is trying to tweak new ones which could result in a sluggish interface. Alternatively, it can be used to process photos alongside tweaking new ones if one has a CPU capable of handling the workload. The Editor tab is where the user tweaks photos. 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. These snapshots are not written to the

and are subsequently lost once the photo has been closed, however work is underway on migrating the PP3 sidecar system to XMP which already supports storing snapshots.

Adjustment tools and processing

* Bayer

algorithms: AMaZE, IGV, LMMSE, EAHD, HPHD, VNG4, DCB, AHD, fast or mono, as well as none. * Raw files from X-Trans sensors have the 3-pass, 1-pass and fast demosaicing methods at their disposal. * Processing profiles support via

s with the ability to fully and partially load, save and copy profiles between images * Processing parameters can be generated dynamically based on image metadata using the Dynamic Profile Builder. * Exposure control and curves in the L*a*b* and

RGB The RGB color model is an additive color model in which the red, green and blue primary colors of light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three addi ...

color spaces *

CIECAM02 In colorimetry, CIECAM02 is the color appearance model published in 2002 by the International Commission on Illumination (CIE) Technical Committee 8-01 (''Color Appearance Modelling for Color Management Systems'') and the successor of CIECAM97s. ...

mode * Advanced highlight reconstruction algorithms and shadow/highlight controls *

Tone mapping Tone mapping is a technique used in image processing and computer graphics to map one set of colors to another to approximate the appearance of high-dynamic-range images in a medium that has a more limited dynamic range. Print-outs, CRT or L ...

using edge-preserving decomposition * Pre-crop vignetting correction and post-crop vignetting for artistic effect * Graduated filter * Various methods of sharpening * Various methods of

noise reduction Noise reduction is the process of removing noise from a signal. Noise reduction techniques exist for audio and images. Noise reduction algorithms may distort the signal to some degree. Noise rejection is the ability of a circuit to isolate an und ...

* Detail recovery * Removal of

purple fringing In photography (particularly digital photography), purple fringing (sometimes called PF) is the term for an unfocused purple or magenta "ghost" image on a photograph. This optical aberration is generally most visible as a coloring and lightenin ...

* Manual and automatic pre- and post-demosaic

chromatic aberration In optics, chromatic aberration (CA), also called chromatic distortion and spherochromatism, is a failure of a lens to focus all colors to the same point. It is caused by dispersion: the refractive index of the lens elements varies with the wave ...

correction * Advanced

wavelet A wavelet is a wave-like oscillation with an amplitude that begins at zero, increases or decreases, and then returns to zero one or more times. Wavelets are termed a "brief oscillation". A taxonomy of wavelets has been established, based on the num ...

processing *

Retinex Color constancy is an example of subjective constancy and a feature of the human color perception system which ensures that the perceived color of objects remains relatively constant under varying illumination conditions. A green apple ...

processing *

White balance In photography and image processing, color balance is the global adjustment of the intensities of the colors (typically red, green, and blue primary colors). An important goal of this adjustment is to render specific colors – particularly neu ...

(presets, color temperature, spot white balance and auto white balance) * Channel mixer *

Black-and-white Black-and-white (B&W or B/W) images combine black and white in a continuous spectrum, producing a range of shades of grey. Media The history of various visual media began with black and white, and as technology improved, altered to color. ...

conversion * Color boost and vibrance (saturation control with the option of preserving natural skin tones) * Hue, saturation and value adjustments using curves * Various methods of color toning * Lockable color picker * Wide gamut preview support on Microsoft Windows and Linux (the macOS preview is limited to sRGB) * Soft-proofing support * Color-managed workflow * ICC color profiles (input, working and output) * DCP color profiles (input) * Adobe Lens Correction Profiles (LCP) * Cropping, resizing, post-resize sharpening * Rotation with visual straightening tool *

Distortion In signal processing, distortion is the alteration of the original shape (or other characteristic) of a signal. In communications and electronics it means the alteration of the waveform of an information-bearing signal, such as an audio signal ...

correction * Perspective adjustment *

Dark frame subtraction In digital photography, dark-frame subtraction is a way to reduce image noise in photographs shot with long exposure times, at high ISO sensor sensitivity or at high temperatures. It takes advantage of two components of image noise that remain the ...

* Flat field removal (hue shifts, dust removal, vignetting correction) * Hot and dead pixel filters * Metadata (

and

IPTC The International Press Telecommunications Council (IPTC), based in London, United Kingdom, is a consortium of the world's major news agencies, other news providers and news industry vendors and acts as the global standards body of the news media. ...

) editor * A processing queue to free up the CPU during editing where instant feedback is important and to make maximal use of it afterwards

Output formats

The output format can be selected from: * TIFF (8-bit, 16-bit, 16-bit float, 32-bit float) * JPEG (8-bit) * PNG (8-bit and 16-bit)

References

External links

* {{Raster graphics editors Digital photography Formerly proprietary software Free graphics software Free photo software Free software programmed in C++ Graphics software that uses GTK Photo software for Linux Raw image processing software