Darktable, an open-source answer to Adobe Lightroom, has announced a major update to version 4.0 which adds a massive list of changes, new features, and bug fixes including new color science tools and a totally new user interface.
The first notable change involves new color science tools, specifically color and exposure mapping. These enable users to define a target color or exposure in order to match that color with a source object in the image. This feature can be used to perform white balance against non-gray objects of known color or applied across a series of images to make them more consistent.
Darktable 4.0 also brings support for what it calls Filmic v6. This new color science removes mandatory desaturation close to medium white and black and replaces it with true gamut mapping. Obry says the result is more saturated colors and bluer skies. Filmic v6 also adds what Darktable calls “hue handcuff” which prevents the shift of hues that can degrade. which it says helps, skies remain blue rather than shifting to cyan and keeps reds from slipping into a warmer yellow.
“This gamut sanitization is the third and last to be added to Darktable, which now has a fully-sanitized color pipeline from input (color calibration), through artistic changes (color balance rgb) to output (filmic v6),” the Obry says. “Users can now color-grade pictures safely in the knowledge that invalid input colors can be recovered in the least destructive fashion possible early in the pipeline, and valid colors can’t be pushed out of gamut along the pipeline.”
Darktable 4.0 also adds what is referred to as the “guided laplacian” method of highlight reconstruction. Users can deploy an iterative and multi-scale wavelet scheme to bring out more details from RBG channels. This laplacian technique limits color bleeding when the color becomes clipped. This feature is only available for Bayer sensor images, not X-Trans sensor images.
The update also introduces Uniform Color Space 2022 (USC22). According to DarkTable, UCS22 is a perceptually uniform color space designed for the purpose of artistic saturation changes in the RGB module. It allows for gamut mapping at a constant brightness and better saturation control in RGB color balance.
The user interface of Darktable has also been completely rewritten in version 4.0. Obry says the app has been revamped to improve its look and consistency, and padding, margins color, contrast, alignment, and icons have been reworked throughout. Orby also notes that collapsible sections within modules have been redesigned so their functionality is more obvious and better-looking, and multiple sections and modules have been cleaned up and adjusted for clarity.
Darktable 4.0 also has performance and OpenCL support changes.
“All performance and OpenCL settings and pixelpipe optimizations have been fully reviewed and updated. Many new optimizations have been added and the user preferences have been simplified,” Obry says. “All configurations are now per-device allowing each OpenCL device to be tuned separately. Performance configuration is now applied at runtime and no longer requires darktable to be restarted when changed.”
The above are just the most obvious, major changes, but the full changelog on Darktable shows a huge list of 23 additional changes from expanded vocabulary for average skin colors for three body parts in six ethnicities, to a new button in the “highlight reconstruction” module allows clipped pixels to be better visualized.
On top of those new features, 20 other bugs have been fixed in Darktable 4.0. All told, there are well over 50 new features and bug fixes (listed both on the Darktable website and Github) which makes the update rather substantial.
Version 4.0 can be downloaded from Darktable and is available for Windows, macOS, and some Linux packages capable of supporting a graphical session.