processing modules on darktable 5.6 user manual

AgX

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: applies a tone mapping curve. inspired by Blender’s AgX tone mapper.
purpose: corrective and creative.
input: linear, RGB, scene-referred.
processing: non-linear, RGB.
output: linear, RGB, display-referred.

Transform the colors and tonal range of an image to fit a display.

The primary innovation of the AgX module is an advanced color handling method that ensures a natural and film-like appearance, preventing the oversaturation artifacts common with simpler tone mapping techniques. It is derived from the display transform of the same name, used in the Blender 3D modeler by T. J. Sobotka, Eary_Chow, Sakari Kapanen and others.

astrophoto denoise

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: apply a poisson noise removal best suited for astrophotography.
purpose: corrective.
input: non-linear, Lab, display-referred.
processing: non-linear, Lab.
output: non-linear, Lab, display-referred.

Remove image noise while preserving structure.

This is accomplished by averaging each pixel with some surrounding pixels in the image. The weight of such a pixel in the averaging process depends on the similarity of its neighborhood with the neighborhood of the pixel being denoised. A patch with a defined size is used to measure that similarity.

base curve

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: apply a view transform based on personal or camera maker look, for corrective purposes, to prepare images for display.
purpose: corrective.
input: linear, RGB, display-referred.
processing: non-linear, RGB.
output: non-linear, RGB, display-referred.

Simulate the in-camera JPEG by applying a characteristic base curve to the image.

darktable comes with a number of base curve presets that attempt to mimic the curves of various camera manufacturers. These presets are automatically applied according to the “maker ID” found in the image’s Exif data. Camera-specific base curve presets are also available for some camera models.

bloom

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: apply Orton effect for a dreamy ethereal look.
purpose: creative.
input: non-linear, Lab, display-referred.
processing: non-linear, Lab.
output: non-linear, Lab, display-referred.

Create a soft bloom effect.

This module works by blurring the highlights and then blending the result with the original image.

Note: This module performs blurs in Lab color space, and is no longer recommended. Instead, use the tone equalizer module or the exposure module with a parametric mask.

blurs

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: simulate physically-accurate lens and motion blurs.
purpose: creative.
input: linear, RGB, scene-referred.
processing: linear, RGB.
output: linear, RGB, scene-referred.

Simulate physically-accurate blurs in scene-referred RGB space.

🔗blur types

Three types of blur are provided:

lens blur: Simulates a lens diaphragm with a configurable number of blades and blade curvature to create synthetic bokeh.
motion blur: Simulates the effect of camera motion with a configurable path.
gaussian blur: This is not really an optical blur but can be used for denoising or for creative effects using blend modes

A diagram at the top of the module shows the shape of the blurring operator (known as the point spread function). The module will turn each luminous point from the scene into a blot shaped like the displayed blurring operator, with the size of the blot defined by the blur radius.

censorize

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: censorize license plates and body parts for privacy.
purpose: creative.
input: linear or non-linear, RGB, scene-referred.
processing: frequential, RGB.
output: special, RGB, scene-referred.

Degrade parts of the image in an aesthetically pleasing way, in order to anonymize people/objects or hide body parts.

Censorize works in linear RGB color space to apply a physically-accurate gaussian blur and gaussian luminance noise.

Aside from anonymization, this module can also be used for a wide range of creative purposes, for example:

chromatic aberrations

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: correct chromatic aberrations.
purpose: corrective.
input: linear, RGB, scene-referred.
processing: linear, RGB.
output: linear, RGB, scene-referred.

Correct chromatic aberrations.

In contrast to the raw chromatic aberrations module, this module does not require raw data as input.

🔗workflow

To obtain the best result, you are advised to proceed as follows:

Attenuate the chromatic aberrations as much as possible in the lens correction module using the TCA sliders.
Increase the strength slider in this module to better see its effect.
Increase the radius until the chromatic aberrations disappear. If this is insufficient, try enabling the “very large chromatic aberrations” setting.
Choose the guide that gives the best result in term of sharpness and artifacts.
Reduce the strength to avoid washing out the colors too much.

For more complicated cases you could also try the following:

color balance

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: shift colors selectively by luminance range.
purpose: corrective or creative.
input: linear, Lab, scene-referred.
processing: non-linear, RGB.
output: non-linear, Lab, scene-referred.

A versatile tool for adjusting the image’s color balance.

This module can be used to revert parasitic color casts or to enhance the visual atmosphere of an image using color grading, a popular technique in the cinema industry. For scene-referred workflow, you should consider using the improved color balance rgb module instead.

color balance rgb

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: color grading tools using alpha masks to separate shadows, mid-tones and highlights.
purpose: corrective or creative.
input: linear, RGB, scene-referred.
processing: non-linear, RGB.
output: non-linear, RGB, scene-referred.

An advanced module which brings color-grading tools from cinematography into the photographic scene-referred pipeline.

This module is not suitable for beginners with no prior knowledge of color theory, who might want to stick to the global chroma and global vibrance settings until they have a good understanding of the dimensions of color.

color calibration

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: perform color space corrections such as white balance, channels mixing and conversions to monochrome emulating film.
purpose: corrective or creative.
input: linear, RGB, scene-referred.
processing: linear, RGB or XYZ.
output: linear, RGB, scene-referred.

A fully-featured color-space correction, white balance adjustment and channel mixer module.

This simple yet powerful module can be used in the following ways:

To adjust the white balance (chromatic adaptation), working in tandem with the white balance module. Here, the white balance module makes some initial adjustments (required for the demosaic module to work effectively), and the color calibration module then calculates a more perceptually-accurate white balance after the input color profile has been applied.

color contrast

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: increase saturation and separation between opposite colors.
purpose: creative.
input: non-linear, Lab, display-referred.
processing: non-linear, Lab.
output: non-linear, Lab, display-referred.

A simplified control for changing the contrast or separation of colors between the green/magenta and blue/yellow axes in Lab color space. Higher values increase color contrast, lower values decrease it.

🔗module controls

green-magenta contrast: Change the green-magenta color contrast. This is equivalent to raising or lowering the steepness of the a* curve in Lab. Lower values desaturate greens and magenta, while higher values increase their saturation.
blue-yellow contrast: Change the blue-yellow color contrast. This is equivalent to raising or lowering the steepness of the b* curve in Lab. Lower values desaturate blues and yellows, while higher values increase their saturation.

color correction

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: correct white balance selectively for blacks and whites.
purpose: corrective or creative.
input: non-linear, Lab, display-referred.
processing: non-linear, Lab.
output: non-linear, Lab, display-referred.

Modify the global image saturation to give the image a tint or as an alternative method to split-tone the image.

Note: Use the color balance rgb module for color modifications.

🔗module controls

color board: For split toning move the white dot to the desired highlight tint and then select a tint for shadows with the dark spot. For a simple global tint set both spots to the same color.
saturation: Correct the global saturation.

color equalizer

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: change saturation, hue and brightness depending on local hue.
purpose: corrective and creative.
input: linear, RGB, scene-referred.
processing: quasi-linear, RGB.
output: quasi-linear, RGB, scene-referred.

Selectively adjust the hue, saturation, and/or brightness of pixels based on their current hue.

This module is an attempt to recreate some of the functionality of the color zones module in the scene-referred part of the pipeline whilst overcoming some of that module’s limitations. Specifically, the color zones module is prone to increase chroma/luma noise, and introduce artifacts or harsh transitions. These are somewhat mitigated within color equalizer with the following additions:

color harmonizer

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: harmonize colors toward a selected palette in perceptual space.
purpose: creative color grading.
input: linear, RGB, scene-referred.
processing: darktable UCS / JCH (perceptual).
output: linear, RGB, scene-referred.

The color harmonizer reduces chromatic dissonance by pushing hues toward a selected color palette. This palette is defined by a set of hue angles called harmony nodes. Colors that are “off-palette” are gently pulled toward the nearest node; colors already on a node are left unchanged. A per-node saturation multiplier can additionally boost or reduce the colorfulness of colors near each node.

color look up table

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: perform color space corrections and apply looks.
purpose: corrective or creative.
input: linear or non-linear, Lab, display-referred.
processing: defined by profile, Lab.
output: linear or non-linear, Lab, display-referred.

A generic color look up table implemented in Lab space.

The input to this module is a list of source and target points and the complete mapping is interpolated using splines. The resulting look up tables (LUTs) are editable by hand and can be created using the darktable-chart utility to match given input (such as hald-cluts and RAW/JPEG with in-camera processing pairs). See using darktable-chart for details.

color mapping

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: transfer a color palette and tonal repartition from one image to another.
purpose: creative.
input: linear or non-linear, Lab, display-referred.
processing: non-linear, Lab.
output: non-linear, Lab, display-referred.

Transfer the look and feel of one image to another.

This module statistically analyses the color characteristics of a source and target image. The colors of the source image are then mapped to corresponding colors on the target image.

Two steps are required to use this module:

color reconstruction

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: recover clipped highlights by propagating surrounding colors.
purpose: corrective.
input: linear or non-linear, Lab, display-referred.
processing: non-linear, Lab.
output: non-linear, Lab, display-referred.

Recover color information in blown-out highlights.

Due to the nature of digital sensors, overexposed highlights lack valid color information. Most frequently they appear neutral white or exhibit some color cast, depending on what other image processing steps are involved. This module can be used to “heal” overexposed highlights by replacing their colors with better fitting ones. The module acts on pixels whose luminance exceeds a user-defined threshold. Replacement colors are taken from neighboring pixels. Both the spatial distance and the luminance distance (range) are taken into account for color selection.

color zones

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: selectively shift hues, chroma and lightness of pixels.
purpose: creative.
input: linear or non-linear, Lab, display-referred.
processing: non-linear, Lab.
output: non-linear, Lab, display-referred.

Selectively adjust the lightness, chroma and hue of pixels based on their current lightness, chroma and hue.

This module works in CIE LCh color space, which separates pixels into lightness, chroma and hue components. It allows you to manipulate the lightness, chroma and hue of targeted groups of pixels through the use of curves.

colorize

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: overlay a solid color on the image.
purpose: creative.
input: linear or non-linear, Lab, display-referred.
processing: non-linear, Lab.
output: non-linear, Lab, display-referred.

Add a solid layer of color to the image.

🔗module controls

hue: The hue of the color layer.
saturation: The saturation of shadow tones.
lightness: The lightness of the color layer.
source mix: Controls how the lightness of the input image is mixed with the color layer. Setting this to zero will result in a uniformly colored plane.

composite

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: combine the image with elements from another processed image (move this module to after output color profile if you see banding).
purpose: corrective and creative.
input: linear, RGB, scene-referred.
processing: linear, RGB.
output: linear, RGB, scene-referred.

Create a composite image by overlaying an already-processed image on top of the current image.

Drag and drop a processed image from the filmstrip onto the “drop image from filmstrip here” box to overlay the chosen image, and then alter the various placement and adjustment attributes of the image being overlaid.

contrast equalizer

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: add or remove local contrast, sharpness, acutance.
purpose: corrective and creative.
input: linear, Lab, scene-referred.
processing: frequential, RGB.
output: linear, Lab, scene-referred.

Adjust luminance and chroma contrast in the wavelet domain.

This versatile module can be used to achieve a variety of effects, including bloom, denoise, clarity, and local contrast enhancement.

It works in the wavelet domain and its parameters can be tuned independently for each wavelet detail scale. The module operates in CIE LCh color space and so is able to treat luminosity and chromaticity independently.

crop

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: change the framing.
purpose: corrective or creative.
input: linear, RGB, scene-referred.
processing: geometric, RGB.
output: linear, RGB, scene-referred.

Crop an image using on-screen guides.

This module appears later in the pipeline than the deprecated crop and rotate module, meaning that the full image can remain available for source spots in the retouch module. For best results, you are advised to use the rotate and perspective module to perform rotation and perspective correction (if required), and then perform final creative cropping with this module.

demosaic

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: reconstruct full RGB pixels from a sensor color filter array reading.
purpose: mandatory.
input: linear, raw, scene-referred.
processing: linear, raw.
output: linear, RGB, scene-referred.

Control how raw files are demosaiced and optionally apply capture sharpening.

🔗bayer filters

The sensor cells of a digital camera (commonly named “photosites”) are not color-sensitive – they are only able to record different levels of lightness. In order to obtain a color image, each cell is covered by a colored filter (red, green or blue) that primarily passes light of that color. This means that each photosite (and therefore each “pixel” of the raw image) only contains information about a single color channel.

denoise (profiled)

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: denoise using noise statistics profiled on sensors.
purpose: corrective.
input: linear, RGB, scene-referred.
processing: linear, RGB.
output: linear, RGB, scene-referred.

An easy to use and highly efficient denoise module, adapted to the individual noise profiles of a wide range of camera sensors.

One issue with a lot of denoising algorithms is that they assume that the variance of the noise is independent of the luminosity of the signal. By profiling the noise characteristics of a camera’s sensor at different ISO settings, the variance at different luminosities can be assessed, and the denoising algorithm can be adjusted to more evenly smooth out the noise.

diffuse or sharpen

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: simulate directional diffusion of light with heat transfer model to apply an iterative edge-oriented blur, inpaint damaged parts of the image, or to remove blur with blind deconvolution.
purpose: corrective and creative.
input: linear, RGB, scene-referred.
processing: linear, RGB.
output: linear, RGB, scene-referred.

Diffusion is a family of physical processes by which particles move and spread gradually with time, from a source that generates them. In image processing, diffusion mostly occurs in two places:

dither or posterize

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: reduce banding and posterization effects in output JPEGs by adding random noise, or reduce bit depth.
purpose: corrective, artistic.
input: non-linear, RGB, display-referred.
processing: non-linear, RGB.
output: non-linear, RGB, display-referred.

This module eliminates some of the banding artifacts that can result when darktable’s internal 32-bit floating point data is transferred into discrete 8-bit or 16-bit integer output format for display or export. It can also be used for creative posterization effects.

enlarge canvas

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: add empty space to the left, top, right or bottom.
purpose: corrective and creative.
input: linear, RGB, scene-referred.
processing: linear, RGB.
output: linear, RGB, scene-referred.

Increase the size of the image canvas and fill the additional area with the selected color.

🔗module controls

percent left: The amount of enlargement to the left of the image.
percent right: The amount of enlargement to the right of the image.
percent top: The amount of enlargement to the top of the image.
percent bottom: The amount of enlargement to the bottom of the image.
color: The color with which to fill the additional area.

exposure

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: redo the exposure of the shot as if you were still in-camera using a color-safe brightening similar to increasing ISO setting.
purpose: corrective and creative.
input: linear, RGB, scene-referred.
processing: linear, RGB.
output: linear, RGB, scene-referred.

Increase or decrease the overall brightness of an image.

This module has two modes of operation:

manual: Set the exposure and black level manually
automatic (RAW images only): Use an analysis of the image’s histogram to automatically set the exposure. Darktable automatically selects the exposure compensation that is required to shift the selected percentile to the selected target level (see definitions below). This mode is particularly useful for automatically altering a large number of images to have the same exposure. A typical use case of automatic mode is deflickering of time-lapse photographs.

🔗module controls

mode: Choose the mode of operation (automatic/manual).
compensate camera exposure (manual mode): Automatically remove the camera exposure bias (taken from the image’s Exif data).
highlight preservation mode (manual mode): Some cameras underexpose the raw file in specific modes such as HDR, dynamic range expansion, HLG or AutoLightingOptimizer to protect the highlights. When enabled, it restores the withheld exposure (the amount, in EV, is shown on the button). This control appears only when such a mode is detected in the image’s Exif data.
exposure (manual mode): Increase (move to the right) or decrease (move to the left) the exposure value (EV). To adjust by more than the default limits shown on the slider, right click and enter the desired value up to +/-18 EV (see module controls).; The picker tool on the right sets the exposure such that the average of the selected region matches the target lightness defined in area exposure mapping options.
percentile (automatic mode): Define a location in the histogram to use for automatic exposure correction. A percentile of 50% denotes a position in the histogram where 50% of pixel values are above and 50% of pixel values are below that exposure.
target level (automatic mode): Define the target level for automatic exposure correction (EV) relative to the white point of the camera.
black level correction (manual and automatic modes): Adjust the black level point to unclip negative RGB values.

Note: Do not use the black level correction to add more density in blacks as this can clip near-black colors out of gamut by generating negative RGB values. This can cause problems with some modules later in the pixelpipe. Instead, use a tone mapping curve to add density to the blacks. For example, you can use the relative black exposure slider on the scene tab of the filmic rgb module, or establish a deeper toe in the base curve module.

external raster mask

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: read PFM/PNG files recorded for use as raster masks.
purpose: corrective or creative.
input: linear, raw, scene-referred.
processing: linear, raw.
output: linear, raw, scene-referred.

Generate a raster mask from a .pfm to be used by subsequent processing modules.

Note: .pfm files are not very common but darktable and GIMP can both generate such files. Both grayscale and RGB files are supported.

🔗usage

Raster masks are automatically created whenever you define a mask within a processing module, for subsequent re-use in modules further up the pixelpipe. In some cases you might want such a mask to be generated by other software, for example to make use of software that can isolate a subject from its background, or simply to add some background pattern.

filmic rgb

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: apply a view transform to prepare the scene-referred pipeline for display on SDR screens and paper prints while preventing clipping in non-destructive ways.
purpose: corrective and creative.
input: linear or non-linear, RGB, scene-referred.
processing: non-linear, RGB.
output: non-linear, RGB, display-referred.

Remap the tonal range of an image by reproducing the tone and color response of classic film.

This module can be used either to expand or to contract the dynamic range of the scene to fit the dynamic range of the display. It protects colors and contrast in the mid-tones, recovers the shadows, and compresses bright highlights and dark shadows. Highlights will need extra care when details need to be preserved (e.g. clouds).

framing

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: add solid borders or margins around the image.
purpose: creative.
input: linear or non-linear, RGB, display-referred.
processing: geometric, RGB.
output: linear or non-linear, RGB, display-referred.

Generate a frame around the image.

The frame consists of a border (with a user-defined color) and a frame line within that border (with a second user-defined color). Various options are available to control the geometry and color of the frame.

🔗module controls

border size: The size of the frame as a percentage of the underlying full image.
aspect: The aspect ratio of the final module output (i.e. the underlying image plus the frame). Right-click on the slider to enter a custom aspect as a ratio (e.g. “6:5”).
orientation: The orientation of the frame (portrait/landscape). Select ‘auto’ for darktable to choose the most reasonable orientation based on the underlying image.
horizontal/vertical position: Select from a set of pre-defined ratios to control where the underlying image will be positioned on the horizontal/vertical axis. You can also right click and enter your own ratio as “x/y”.
frame line size: The percentage of the frame line size, relative to the border size at its smallest part.
frame line offset: The position of the frame line, relative to the underlying image. Choose 0% for a frame line that touches the image. Choose 100% for a frame line that touches the outer border.
border color / frame line color: A pair of color selectors which allow the border and frame line colors to be defined. Clicking on the colored field will open a color selector dialog which offers a choice of commonly-used colors, or allows you to define a color in RGB color space. You can also activate a picker to take a color probe from the image.
show guides: Tick the box to show guide overlays whenever the module is activated. Click the icon on the right to control the properties of the guides. See guides & overlays for details.

graduated density

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: simulate an optical graduated neutral density filter.
purpose: corrective and creative.
input: linear or non-linear, RGB, scene-referred.
processing: non-linear, RGB.
output: non-linear, RGB, display-referred.

Simulate a graduated density filter in order to correct exposure and color in a progressive manner.

A line is shown on screen allowing the position and rotation of the gradient to be modified with the mouse.

This module is known to provoke banding artifacts under certain conditions. You should consider activating the dither or posterize module to alleviate these issues.

grain

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: simulate silver grains from film.
purpose: creative.
input: non-linear, Lab, display-referred.
processing: non-linear, Lab.
output: non-linear, Lab, display-referred.

Simulate the grain of analog film. The grain is processed on the L channel of Lab color space.

🔗module controls

coarseness: The grain size, scaled to simulate an ISO number.
strength: The strength of the effect.
mid-tone bias: The bias toward the mid-tones. As the bias increases, the grain becomes less visible in the shadows and highlights.

haze removal

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: remove fog and atmospheric hazing from images.
purpose: corrective.
input: linear, RGB, scene-referred.
processing: frequential, RGB.
output: linear, RGB, scene-referred.

Automatically reduce the effect of dust and haze in the atmosphere. This module may also be employed more generally to give images a color boost specifically in low-contrast regions of the image.

Haze absorbs light from objects in the scene but it is also a source of diffuse background light. The haze removal module first estimates, for each image region, the amount of haze in the scene. It then removes the diffuse background light according to its local strength and recovers the original object light.

highlight reconstruction

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: avoid magenta highlights and try to recover highlights colors.
purpose: corrective.
input: linear, raw, scene-referred.
processing: reconstruction, raw.
output: linear, raw, scene-referred.

Attempt to reconstruct color information for pixels that are clipped in one or more RGB channel.

🔗clipping

Clipping occurs when the amount of captured light exceeds either the capacity of a camera’s sensor to record that light (photosite saturation) or the capacity of the Raw file to store it (digital clipping). Once a pixel is clipped we can no longer know the precise brightness of that pixel – only that it is equal to or greater than the maximum value that pixel can store.

highpass

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: isolate high frequencies in the image.
purpose: creative.
input: linear or non-linear, Lab, scene-referred.
processing: frequential, Lab.
output: special, Lab, scene-referred.

A high pass filter.

This module is primarily intended to be used in combination with a blend mode. For example, try using the module with a blend mode of “soft light” for high pass sharpening.

Note: This module performs blurs in Lab color space, which can result in undesirable effects, and is no longer recommended. Instead, use the contrast equalizer module for fine sharpness or the local contrast module for general sharpness.

hot pixels

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: remove abnormally bright pixels by dampening them with neighbors.
purpose: corrective.
input: linear, raw, scene-referred.
processing: reconstruction, raw.
output: linear, raw, scene-referred.

Automatically detect and eliminate hot pixels.

Hot pixels are pixels which have failed to record a light level correctly. Detected hot pixels are replaced by an average of their neighbors.

🔗module controls

threshold: The minimum brightness for a pixel to be considered a hot pixel candidate.
strength: The sensitivity of detection; higher values will fix more pixels by requiring less deviation from their neighbors.
detect by 3 neighbours: Extend the detection of hot pixels – regard a pixel as hot if a minimum of only three (instead of four) neighbor pixels deviate by more than the threshold level.
mark fixed pixels: Visually mark the corrected pixels on the image and display a count of hot pixels that have been fixed.

input color profile

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: convert any RGB input to pipeline reference RGB using color profiles to remap RGB values.
purpose: mandatory.
input: linear or non-linear, RGB, scene-referred.
processing: defined by profile.
output: linear, RGB, scene-referred.

Define how darktable will interpret the colors of the image.

This module takes the color space used by the image source (e.g. camera, scanner) and converts the pixel encodings to a standardized working color space. This means that subsequent modules in the pipeline don’t need to be concerned with the specifics of the input device, and can work with and convert to/from a common working color space.

lens correction

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: correct lenses optical flaws.
purpose: corrective.
input: linear, RGB, scene-referred.
processing: geometric and reconstruction, RGB.
output: linear, RGB, scene-referred.

Automatically correct for (or simulate) lens distortion, transverse chromatic aberrations (TCA) and vignetting.

You can choose to either use lens correction data embedded in your RAW file (where present/supported) or correction data provided by the external Lensfun library.

Additional controls are also provided for manual vignetting correction, in case the profiles for your lens are insufficient or missing.

liquify

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: distort parts of the image.
purpose: creative.
input: linear, RGB, scene-referred.
processing: geometric, RGB.
output: linear, RGB, scene-referred.

Move pixels around by applying freestyle distortions to parts of the image using points, lines and curves.

As you might want to use source data from any part of the image you will be shown the uncropped image (possibly with the cropping rectangle overlaid as a guide) while the module is active.

local contrast

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: manipulate local and global contrast separately.
purpose: creative.
input: non-linear, Lab, display-referred.
processing: non-linear, Lab.
output: non-linear, Lab, display-referred.

Enhance the image’s local contrast.

This is achieved using either a local laplacian (default) or unnormalized bilateral filter. Both modes work exclusively on the L channel from Lab. The local laplacian filter has been designed to be robust against unwanted halo effects and gradient reversals along edges.

🔗module controls

mode: Choice of local laplacian filter or bilateral grid. The following sections define the controls available for each of these modes.

🔗bilateral grid

coarseness: Adjust the coarseness of the details to be adjusted.
contrast: Control how strongly the algorithm distinguishes between brightness levels. Increase this parameter for a more contrasty look.
detail: Add or remove detail. Higher values increase local contrast.

🔗local laplacian

To understand the parameters of the local laplacian filter, one can think of it as applying a curve to the image, similar to the following graph:

lowlight vision

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: simulate human night vision.
purpose: creative.
input: non-linear, Lab, display-referred.
processing: linear, XYZ.
output: non-linear, Lab, display-referred.

Simulate human lowlight vision. This module can also be used to perform a day-to-night conversion.

The idea is to calculate a scotopic vision image, which is perceived by the rods rather than the cones in the eyes under low light. Scotopic lightness is then mixed with photopic value (regular color image pixel) using some blending function. This module can also simulate the Purkinje effect by adding some blueness to the dark parts of the image.

lowpass

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: isolate low frequencies in the image.
purpose: creative.
input: linear or non-linear, Lab, scene-referred.
processing: frequential, Lab.
output: special, Lab, scene-referred.

Apply a low pass filter (for example, a Gaussian blur) to the image, while controlling the output contrast and saturation.

This module is primarily intended to be used in combination with a blend mode. For example, try using the local contrast mask preset with the overlay blend mode.

LUT 3D

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: perform color space corrections and apply look.
purpose: corrective or creative.
input: linear, RGB, display-referred.
processing: defined by profile, RGB.
output: linear or non-linear, RGB, display-referred.

Transform RGB values with a 3D LUT file.

A 3D LUT is a tridimensional table that is used to transform a given RGB value into another RGB value. It is normally used for film simulation and color grading.

This module accepts .cube, .3dl, .png (haldclut) and .gmz files. Uncompressed 3D LUT data is not saved in the database or the XMP file, but is instead saved to the 3D LUT file path inside the 3D LUT root folder. It is therefore important to back up your 3D LUT folder properly – sharing an image with its XMP is pointless if the recipient doesn’t also have the same 3D LUT file in their own 3D LUT folder.

monochrome

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: quickly convert an image to black & white using a variable color filter.
purpose: creative.
input: linear or non-linear, Lab, display-referred.
processing: non-linear, Lab.
output: non-linear, Lab, display-referred.

Quickly convert an image to black & white using a variable color filter.

To use this module, first reduce the filter size (to concentrate its effect) and move it across the hue palette to find the best filter value for your desired image rendition. Then gradually expand the filter to include more hues and achieve more natural tonality.

negadoctor

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: invert film negative scans and simulate printing on paper.
purpose: corrective and creative.
input: linear, RGB, display-referred.
processing: non-linear, RGB.
output: non-linear, RGB, display-referred.

Process scanned film negatives.

You can obtain an image of a negative using a film scanner, or by photographing it against a white light (e.g. a light table or computer monitor) or off-camera flash.

🔗preparation

If the image of the negative was obtained using a digital camera, then in order to obtain accurate colors in the final image, you will need to take the following points into consideration:

orientation

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: flip or rotate image by step of 90 degrees.
purpose: corrective.
input: linear, RGB, scene-referred.
processing: geometric, RGB.
output: linear, RGB, scene-referred.

Rotate the image 90 degrees at a time or flip the image horizontally and/or vertically.

The module is enabled by default and the orientation (rotation) is automatically set based on the image’s Exif data.

The orientation can also be set using the actions on selection module in the lighttable view.

output color profile

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: convert pipeline reference RGB to any display RGB using color profiles to remap RGB values.
purpose: mandatory.
input: linear or non-linear, Lab, display-referred.
processing: defined by profile.
output: non-linear, RGB or Lab, display-referred.

Manage the output profile for export and the rendering intent to be used when mapping between color spaces.

darktable comes with pre-defined profiles sRGB, Adobe RGB, XYZ and linear RGB. You can provide additional profiles by placing them in $DARKTABLE/share/darktable/color/out (where $DARKTABLE is the darktable installation directory) or color/out in the darktable configuration directory. Note that these color/out directories are not created by the darktable install; if you need to use one, you must create it yourself.

raw black/white point

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: sets technical specificities of the raw sensor touch with great care!.
purpose: mandatory.
input: linear, raw, scene-referred.
processing: linear, raw.
output: linear, raw, scene-referred.

Define camera-specific black and white points.

This module is activated automatically for all raw images. Default settings are applied for all supported cameras. Changes to the defaults are not normally required.

🔗module controls

black level 0-3: The camera-specific black level of the four pixels in the RGGB Bayer pattern. Pixels with values lower than this level are not considered to contain valid data.
white point: The camera-specific white level. All pixels with values above this are likely to be clipped and will be handled accordingly in the highlight reconstruction module.
flat field correction: Use flat field correction to compensate for lens shading. This field only appears for applicable Raw files and will automatically use any GainMap embedded in the Raw. You can choose to disable this correction if desired.

raw chromatic aberrations

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: correct chromatic aberrations for Bayer sensors.
purpose: corrective.
input: linear, raw, scene-referred.
processing: linear, raw.
output: linear, raw, scene-referred.

Correct chromatic aberrations of raw images.

This module currently only works for raw images recorded with a Bayer sensor (the sensor used in the majority of cameras) – for other types of image, you should use the chromatic aberrations module instead.

The module will also not apply any corrections to any photos that have been identified as monochrome (see developing monochrome images for more information).

raw denoise

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: denoise the raw image early in the pipeline.
purpose: corrective.
input: linear, raw, scene-referred.
processing: linear, raw.
output: linear, raw, scene-referred.

Perform denoising on raw image data before it is demosaiced.

This module has been ported from dcraw.

For an AI-based alternative that denoises the raw data as part of a combined denoise/demosaic inference pass, see neural restore and the AI features overview.

🔗module controls

noise threshold: The threshold for noise detection. Higher values lead to stronger noise removal and greater loss of image detail.
coarse/fine curves: The noise of an image is usually a combination of fine-grained and coarse-grained noise. These curves allow the image to be denoised more or less depending on the coarseness of the visible noise. The left of the curve will act on very coarse grain noise, while the right of the curve will act on very fine grain noise.; Raising the curve will result in more smoothing, while lowering it will result in less smoothing. As an example, you can preserve very fine-grained noise by pulling down the rightmost point of the curve to the minimum value.

retouch

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: remove and clone spots, perform split-frequency skin editing.
purpose: corrective.
input: linear, RGB, scene-referred.
processing: geometric and frequential, RGB.
output: linear, RGB, scene-referred.

Remove unwanted elements from your image by cloning, healing, blurring and filling using drawn shapes.

This module extends the capabilities of the deprecated spot removal module (equivalent to this module’s “clone” tool) by including a “heal” tool (based on the heal tool from GIMP), as well as “fill” and “blur” modes. It can also take advantage of wavelet decomposition, allowing the image to be separated into layers of varying detail (from coarse to fine) which can be selectively retouched before being recombined to produce the output image.

rgb curve

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: alter an image’s tones using curves in RGB color space.
purpose: corrective and creative.
input: linear, RGB, display-referred.
processing: non-linear, RGB.
output: linear, RGB, display-referred.

A classic digital photography tool to alter an image’s tones using curves.

This module is very similar to the tone curve module but works in RGB color space.

Activate the picker on the left to show the picked values in the graph (Ctrl+click or right-click to use the picker in area mode). Numerical (Lab) values of the input and output (see below) at the selected spot or area are shown at the top left of the widget.

rgb levels

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: adjust black, white and mid-gray points in RGB color space.
purpose: corrective and creative.
input: linear, RGB, display-referred.
processing: non-linear, RGB.
output: non-linear, RGB, display-referred.

Adjust black, white and mid-gray points in RGB color space. This module is similar to the levels module, which works in Lab color space.

The rgb levels tool shows a histogram of the image, and displays three bars with handles. Drag the handles to modify the black, middle-gray and white points in lightness (in “RGB, linked channels” mode) or independently for each of the R, G and B channels (in “RGB, independent channels” mode).

rgb primaries

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: adjustment of the RGB color primaries for color grading.
purpose: corrective or creative.
input: linear, RGB, scene-referred.
processing: linear, RGB.
output: linear, RGB, scene-referred.

Adjust the hue and purity of the RGB primary colors (i.e. which red, green and blue they represent), while leaving uncolored (gray) pixels unchanged. In addition to preserving gray pixels, the opponency relationships between the colors are also preserved under this adjustment: If you increase the purity of the blue primary, the opponent yellow’s intensity increases to balance things out; If you twist the blue hue toward cyan, the opponent yellow is twisted toward orange.

rotate and perspective

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: rotate or distort perspective.
purpose: corrective or creative.
input: linear, RGB, scene-referred.
processing: geometric, RGB.
output: linear, RGB, scene-referred.

Automatically correct for converging lines, a form of perspective distortion. The underlying mechanism is inspired by Markus Hebel’s ShiftN program. This module also allows for the rotation of the image to be adjusted.

Perspective distortions are a natural effect when projecting a three dimensional scene onto a two dimensional plane and cause objects close to the viewer to appear larger than objects further away. Converging lines are a special case of perspective distortions frequently seen in architectural photographs – parallel lines, when photographed at an angle, are transformed into converging lines that meet at some vantage point within or outside of the image frame.

rotate pixels

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: null.
purpose: null.
input: null.
processing: null.
output: null.

The sensors of some cameras (such as the Fujifilm FinePix S2Pro, F700, and E550) have a diagonally oriented Bayer pattern instead of the usual orthogonal layout.

Without correction this would lead to a tilted image with black corners. This module applies the required rotation.

darktable detects images that need correction using their Exif data and automatically activates this module where required. For other images the module always remains disabled.

scale pixels

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: module for setting pixel aspect ratio useful for certain sensor types and anamorphic desqueeze.
purpose: corrective.
input: linear, RGB, scene-referred.
processing: linear, RGB.
output: linear, RGB, scene-referred.

Some cameras (such as the Nikon D1X) have rectangular instead of the usual square sensor cells. Without correction this would lead to distorted images. This module applies the required scaling.

darktable detects images that need correction using their Exif data and automatically activates this module where required.

shadows and highlights

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: modify the tonal range of the shadows and highlights of an image by enhancing local contrast.
purpose: corrective and creative.
input: linear or non-linear, Lab, display-referred.
processing: non-linear, Lab.
output: non-linear, Lab, display-referred.

Modify the tonal range of the shadows and highlights of an image by enhancing local contrast.

Note: This module performs blurs in Lab color space, which can result in a number of issues when the parameters are pushed hard, including halos, high local contrast in highlights, and hue shifts towards blue in the shadows. You are advised to use the tone equalizer module instead.

sharpen

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: sharpen the details in the image using a standard UnSharp Mask (USM).
purpose: corrective.
input: linear or non-linear, Lab, display or scene-referred.
processing: frequential, Lab.
output: quasi-linear, Lab, display or scene-referred.

Sharpen the details in the image using a standard UnSharp Mask (USM).

This module works by increasing the contrast around edges and thereby enhancing the impression of sharpness of an image. This module is applied to the L channel in Lab color space.

sigmoid

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: apply a view transform to make an image displayable on a screen or print using a robust and smooth tone curve with optional color preservation methods.
purpose: corrective and creative.
input: linear, RGB, scene-referred.
processing: non-linear, RGB.
output: linear, RGB, display-referred.

Remap the tonal range of an image using a modified generalized log-logistic curve.

This module can be used to expand or contract the dynamic range of the scene to fit the dynamic range of the display.

soften

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: create a softened image using the Orton effect.
purpose: creative.
input: linear, RGB, display-referred.
processing: linear, RGB.
output: linear, RGB, display-referred.

Create a softened image using the Orton effect.

Michael Orton achieved his results on slide film by using two exposures of the same scene, one well exposed and one overexposed. He then used a darkroom technique to blend these two images into a final image where the overexposed image was blurred.

split-toning

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: use two specific colors for shadows and highlights and create a linear toning effect between them up to a pivot.
purpose: creative.
input: linear, RGB, scene-referred.
processing: linear, RGB.
output: linear, RGB, scene-referred.

Create a two color linear toning effect where the shadows and highlights are represented by two different colors.

The split-toning module does not convert images to black and white and has limited benefits on color images. In order to perform traditional split-toning, the input to this module should therefore be monochrome.

surface blur

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: apply edge-aware surface blur to denoise or smoothen textures.
purpose: corrective and creative.
input: linear, RGB, scene-referred.
processing: linear, RGB.
output: linear, RGB, scene-referred.

Smooth image surfaces while preserving sharp edges using a bilateral filter.

This module can be used to denoise images, however you should be aware that bilateral filters are susceptible to overshoots and darktable offers much better alternatives. For example, the astrophoto denoise module uses a non-local means denoising algorithm, and the denoise (profiled) module provides a choice between non-local means and wavelet denoising algorithms.

tone curve

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: alter an image’s tones using curves.
purpose: corrective and creative.
input: linear or non-linear, Lab, display-referred.
processing: non-linear, Lab.
output: non-linear, Lab, display-referred.

A classic digital photography tool to alter the tones of an image’s using curves.

This module is very similar to the rgb curve module but works in Lab color space.

Activate the picker to show the picked values on the displayed histogram. Numerical (Lab) values of the input and output (see below) at the selected spot or area are shown at the top left of the graph.

tone equalizer

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: relight the scene as if the lighting was done directly on the scene.
purpose: corrective and creative.
input: linear, RGB, scene-referred.
processing: quasi-linear, RGB.
output: quasi-linear, RGB, scene-referred.

Dodge and burn while preserving local contrast.

The tone equalizer module replaces the need for other tone-mapping modules such as the shadows and highlights, tone curve, zone system (deprecated), and similar modules. It works in linear RGB space and utilizes a user-defined mask to guide the dodging and burning adjustments, helping to preserve local contrast within the image.

unbreak input profile

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: correct input color profiles meant to be applied on non-linear RGB.
purpose: corrective.
input: linear, RGB, display-referred.
processing: non-linear, RGB.
output: non-linear, RGB, display-referred.

Add a correction curve to image data. This is required if you have selected certain input profiles in the input color profile module.

If you decide to use an ICC profile from the camera manufacturer in the input color profile module, a correction curve frequently needs to be pre-applied to image data to prevent the final output from looking too dark. This extra processing is not required if you use darktable’s standard or enhanced color matrices.

velvia

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: resaturate giving more weight to blacks, whites and low-saturation pixels.
purpose: creative.
input: linear, RGB, scene-referred.
processing: linear, RGB.
output: linear, RGB, scene-referred.

Resaturate pixels in a weighted manner that gives more weight to blacks, whites and less saturated pixels.

Note: This module causes hue and brightness shifts that can be difficult to manage. Instead, use the color balance rgb module for color modifications.

🔗module controls

strength: The strength of the effect
mid-tones bias: Reduce the effect on mid-tones in order to avoid unnatural skin tones. Reducing the mid-tone bias decreases mid-tone protection and makes the overall velvia effect stronger.

vignetting

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: simulate a lens fall-off close to edges.
purpose: creative.
input: non-linear, RGB, display-referred.
processing: non-linear, RGB.
output: non-linear, RGB, display-referred.

Apply a vignetting effect to the image.

Vignetting is a modification of the brightness and saturation at the borders of the image in a specified shape. Many of the parameters listed below can also be modified with a graphical control that overlays the image when the module has focus, showing the shape and extent of the effect.

watermark

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: overlay an SVG watermark like a signature on the image.
purpose: creative.
input: non-linear, RGB, display-referred.
processing: non-linear, RGB.
output: non-linear, RGB, display-referred.

Render a vector-based overlay onto your image. Watermarks are standard SVG documents and can be designed using Inkscape.

You can also use bitmap (PNG) images.

The SVG processor in darktable can also substitute strings within an SVG document, allowing image-dependent information to be included in the watermark.

white balance

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: scale raw RGB channels to balance white and help demosaicing.
purpose: corrective.
input: linear, raw, scene-referred.
processing: linear, raw.
output: linear, raw, scene-referred.

Adjust the white balance of the image by altering the temperature and tint, defining a coefficient for each RGB channel, or choosing from list of predefined white balance settings.

The default settings for this module are derived from the camera white balance stored in the image’s Exif data.

(deprecated) basic adjustments

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: apply usual image adjustments.
purpose: creative.
input: linear, RGB, scene-referred.
processing: non-linear, RGB.
output: non-linear, RGB, scene-referred.

Please note that this module is deprecated from darktable 3.6 and should no longer be used for new edits. Please use the quick access panel instead.

A convenience module that combines controls from exposure, highlight reconstruction, color balance and vibrance into a single module.

While this module can provide a quick and convenient way to make simple adjustments to an image, it must be used with care. Normally exposure adjustments should come before input color profile in the pixelpipe, and color adjustments should come after. Because the basic adjustments module combines all of these functions into a single operation in the pixelpipe, it may not play nicely with other modules. Therefore, if you plan to use basic adjustments with other modules, please instead consider using the exposure + base curve / tone curve / filmic rgb + color balance modules so that these operations occur in the correct places in the pixelpipe.

(deprecated) channel mixer

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: perform color space corrections such as white balance, channels mixing and conversions to monochrome emulating film.
purpose: corrective or creative.
input: linear, RGB, display-referred.
processing: linear, RGB.
output: linear, RGB, display-referred.

Please note that this module is deprecated from darktable 3.4 and should no longer be used for new edits. Please use the color calibration module instead.

A simple yet powerful tool to manage color channels.

This module accepts red, green and blue channels as an input and provides red, green, blue, gray, hue, saturation and lightness channels as output. It allows you to independently control how much each input channel contributes to each output channel.

(deprecated) contrast brightness saturation

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: adjust the look of the image.
purpose: creative.
input: non-linear, Lab, display-referred.
processing: non-linear, Lab.
output: non-linear, Lab, display-referred.

Please note that this module is deprecated from darktable 4.4 and should no longer be used for new edits. Please use the color balance rgb module instead.

A very basic tool for adjusting the contrast, brightness and saturation of an image. Please note that a number of other modules provide much more versatile methods of adjusting these parameters.

(deprecated) crop and rotate

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: change the framing and correct the perspective.
purpose: corrective or creative.
input: linear, RGB, scene-referred.
processing: geometric, RGB.
output: linear, RGB, scene-referred.

Please note that this module is deprecated from darktable 3.8 and should no longer be used for new edits. Please use the crop module to crop the image, the rotate and perspective module to perform rotation and keystone correction, and the orientation module to flip the image on the horizontal/vertical axes.

(deprecated) defringe

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: attenuate chromatic aberration by desaturating edges.
purpose: corrective.
input: linear or non-linear, Lab, display-referred.
processing: non-linear, Lab.
output: non-linear, Lab, display-referred.

Please note that this module is deprecated from darktable 3.6 and should no longer be used for new edits. Please use the chromatic aberrations module instead.

Remove color fringing, which often results from Longitudinal Chromatic Aberrations (LCA), also known as Axial Chromatic Aberrations.

This module uses edge-detection. Where pixels are detected as a fringe, the color is rebuilt from less saturated neighboring pixels.

(deprecated) fill light

Mon, 01 Jan 0001 00:00:00 +0000

Please note that this module is deprecated from darktable 3.4 and should no longer be used for new edits. Please use the tone equalizer module or the exposure module with a drawn mask.

Locally modify exposure based on pixel lightness.

This module pushes exposure by increasing lightness with a Gaussian curve of a specified width, centered on a given lightness.

🔗module controls

exposure: The fill-light exposure (EV)
center: The median lightness impacted by the fill-light. The lightness must be set manually but a picker can be used to provide a guide based on a sample from the image. The lightness of the selected point/area is displayed in the gradient bar.
width: The width of the Gaussian curve. This number is expressed in zones, with the full range being 10 zones.

(deprecated) global tonemap

Mon, 01 Jan 0001 00:00:00 +0000

Please note that this module is deprecated from darktable 3.4 and should no longer be used for new edits. Please use the filmic rgb module instead.

Compress the tonal range of an HDR image into the limited tonal range of a typical LDR output file.

Global tonemap processes each pixel of an HDR image, without taking the local surrounding into account. This is generally faster than local tone mapping (deprecated), but might lead to less convincing results with very high-dynamic-range scenes.

(deprecated) invert

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: invert film negatives.
purpose: corrective.
input: linear, raw, display-referred.
processing: linear, raw.
output: linear, raw, display-referred.

Please note that this module is deprecated from darktable 3.4 and should no longer be used for new edits. Please use the negadoctor module instead.

Invert scanned negatives.

🔗module controls

color of film material: Clicking on the colored field will open a color selector dialog which offers you a choice of commonly used colors, or allows you to define an RGB color. You can also activate the picker to take a color probe from your image – preferably from the unexposed border of your negative.

(deprecated) levels

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: adjust black, white and mid-gray points.
purpose: creative.
input: linear or non-linear, Lab, display-referred.
processing: non-linear, Lab.
output: non-linear, Lab, display-referred.

Please note that this module is deprecated from darktable 4.4 and should no longer be used for new edits. Please use the rgb levels module instead.

Adjust black, white and mid-gray points.

The levels tool offers two modes of operation:

manual: The levels tool shows a histogram of the image, and displays three bars with handles. Drag the handles to modify the black, middle-gray and white points in absolute values of image lightness (the L value from Lab).; Moving the black and white bars to match the left and right borders of the histogram will make the output image span the full available tonal range, increasing the image’s contrast.

(deprecated) spot removal

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: remove sensor dust spots.
purpose: corrective.
input: linear, RGB, scene-referred.
processing: geometric, raw.
output: linear, RGB, scene-referred.

Please note that this module is deprecated from darktable 3.6 and should no longer be used for new edits. Please use the “cloning” tool in the retouch module instead.

Correct areas of an image (the target) using details from another area of the image (the source).

This module uses some of the shapes that are available for drawn masks (circles, ellipses and paths), and the user interface is similar.

(deprecated) tone mapping

Mon, 01 Jan 0001 00:00:00 +0000

Please note that this module is deprecated from darktable 3.4 and should no longer be used for new edits. Please use the tone equalizer module instead.

Compress the tonal range of HDR images so that they fit into the limits of an LDR image, using Durand’s 2002 algorithm.

The underlying algorithm uses a bilateral filter to decompose an image into a coarse base layer and a detail layer. The contrast of the base layer is compressed, while the detail layer is preserved, then both layers are re-combined.

(deprecated) vibrance

Mon, 01 Jan 0001 00:00:00 +0000

Technical information

description: saturate and reduce the lightness of the most saturated pixels to make the colors more vivid.
purpose: creative.
input: linear or non-linear, Lab, display-referred.
processing: non-linear, Lab.
output: non-linear, Lab, display-referred.

Please note that this module is deprecated from darktable 3.6 and should no longer be used for new edits. Please use the vibrance control in the color balance rgb module instead.

Saturate and reduce the lightness of the most saturated pixels to make the colors more vivid.

(deprecated) zone system

Mon, 01 Jan 0001 00:00:00 +0000

Please note that this module is deprecated from darktable 3.4 and should no longer be used for new edits. Please use the tone equalizer or multiple instances of the exposure module with parametric masks to narrow down on a zone.

Adjust the lightness of an image using Ansel Adams’ zone system.

The lightness of the image (the L channel in Lab color space) is divided into a number of zones ranging from pure black to pure white. These zones are displayed in a zonebar beneath a preview image. The number of zones can be changed by mouse-scrolling on that bar (default 10 zones).