Darktable

Features

darktable involves the concept of non-destructive editing, similar to that of some other raw manipulation software. Rather than being immediately applied to raster data of the image, the program keeps the original image data until final rendering at the exporting stage (the adjustment parameters made by a user are however visible in real-time). The program features built-in ICC profiles, GPU acceleration (based on OpenCL), and supports most common image formats.

Masks

A major new feature in version 1.4 is support for drawn masks, allowing application of effects to manually specified areas of an image. There are five mask types available: brush, circle, ellipse, bezier path, and gradient. All are resizable, allow fade-out radius for smooth blending and can have their opacity controlled. An arbitrary number of masks can be created and are collected into a "mask manager" on the left hand side of the darkroom UI.

Color

darktable has built-in ICC profile support for sRGB, Adobe RGB, XYZ and linear RGB color spaces.

Importing/exporting

Raw image formats, JPEG, HDR and PFM images can be imported from disk or camera, and exported to disk, Picasa Web Albums, Flickr, email, and to a simple HTML-based web gallery as JPEG, PNG, TIFF, PPM, PFM and EXR images.

Scripting

darktable can be controlled by scripts written in Lua version 5.2. Lua can be used to define actions which darktable should perform whenever a specified event is triggered. One example might be calling an external application during file export in order to apply additional processing steps outside of darktable.

Multi-mode histogram

Multiple histogram types are available, all with individually selectable red, green and blue channels: linear, logarithmic and waveform (new in version 1.4).

User interface

darktable has two main modes, lighttable and darkroom. Each represents a step in the image development process. Two more modes are tethering and a map view. Upon launching, “lighttable” opens by default, where image collections are listed. All panels in all modes can be minimized to save screen real estate.

The left panel is for importing images, displaying Exif information, and filtering. Rating and categorizing buttons are at the top, while the right-side panel features various modules such as a metadata editor and a tag editor. A module used to export images is located at the bottom-right.

The second, "darkroom", mode displays the image at center, with four panels around it; most tools appear on the right side. The left panel displays a pannable preview of the current image, an undo history stack, a color picker, and Exif information. A filmstrip with other images is displayed at the bottom, and can be sorted and filtered using lists from the upper panel. The latter also gives access to the preferences configuration. darktable's configuration allows custom keyboard shortcuts and personalized defaults.

The third mode allows tethering through gPhoto to some of the cameras which support it.

The fourth mode can display maps from different online sources and geotags images by drag and drop. It also uses maps to show images already geotaged by a camera.

Plugins

As of March 2012, darktable includes 47 image adjustment plugins, which it divides into 5 groups;

Plugins for simple well-known photo adjustment operations include crop and rotate; base curve presets, which sets general basecurve presets to automatically improve contrast and colors; exposure controls; highlight reconstruction; demosaic; white balance; and color invert, which allows defining the color of the "film" with a color picker.

Plugins related to contrast and lighting include fill light for modifying the exposure based on pixel lightness; levels to set black, grey and white points; tone curve; zone system; and tone mapping.

Plugins related to hue and saturation include overexposed, to display pixels outside dynamic range; velvia, which mimics Velvia film colors by increasing saturation on lower saturated pixels more than on highly saturated pixels; channel mixer; color contrast; color correction, to modify the global saturation or to give a tint; color zones; color transfer; vibrance; and input/output/display color profile management.

Plugins for repairing visual imperfections include sharpen; equalizer; denoise (non-local means); denoise (bilateral filter); lens correction using the LensFun library; spot removal; chromatic aberrations; raw denoise; and hot pixels for the correction of defective pixels.

Artistic postprocessing plugins used for visual effects include watermark; framing; split toning; vignetting; soften; grain; highpass; lowpass; monochrome; lowlight vision; shadows and highlights; bloom; colorize; and graduated density.

Version for Microsoft Windows

There is no official version for the operating system Windows.

Google Summer of Code

In 2011, the darktable team participated in the Google Summer of Code (GSoC). The main goals were to remove libglade dependency from darktable and to make room for more modularity. The input system for handling shortcuts was also rewritten and incorporated into version 0.9.

Distribution

darktable is released under the GNU General Public License (3.0 or later) as free software. The current version of darktable works on Linux and OS X. Many Linux distributions include darktable in their default repositories, including Fedora, openSUSE, Arch Linux, and Gentoo Linux. Windows is not natively supported.

darktable also runs on Solaris 11, with packages in IPS format available from the maintainer.

Source code repository

Darktable is hosted on Github. All source code and development information can be found there.

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