Darktable 4.0.0

What's new in this version:

New:
Color and exposure mapping
Filmic v6
Guided laplacian highlight reconstruction
Introducing the darktable Uniform Color Space 2022
UI Rewrite
Performance and OpenCL support changes

Changed:
- Color glossary
- A new "contrast" parameter has been added to the guide line overlay settings, allowing for better visibility of the lines over images
- A new "collection filters" module has been introduced, designed to be easier to use than the filtering in the current "collections" module
- The "recently used collections" module is now incorporated into the "collections" module as a "history" button
- The darkroom's module search facility has been enhanced to also match on any user-defined module names
- Support for EXR 16-bit (half) float export has been added
- All usage of dates/times have been reworked to better support time-zones and differing operating systems. Support for milliseconds has also been added.
- All presets in the "tone equalizer" module have been updated to use scene-referred blending modes.
- The new input system introduced in version 3.8 now handles simultaneous shortcut presses and the responsiveness is greatly improved
- Modifiers (Ctrl/Shift/Ctrl+Shift) can now be used when dragging sliders, to modify the precision of the value changes
- When using the "copy" and "move" functionality in the lighttable, the last directories are remembered independently for each operation.
- It is now possible to scroll over a tabbed module to switch tabs.
- Improved monochrome images support:
- True monochrome images (like those from Leica) and images from cameras that have the color matrix filter in front of the sensor removed, are now treated the same in the user interface as much as possible.
- The tagging suggestion mode has been improved.
- The overlay layout in the print view has been enhanced.
- The "retouch" module's heal iteration limit has been increased for new edits.
- It is now possible to edit a single node on a brush path. You can change the size, opacity and hardness of each node independently.
- A new button in the "highlight reconstruction" module allows clipped pixels to be better visualized.
- The raw overexposure function now shows actual sensor clipping rather than being adjusted according to the white balance of the image. This is better suited to the default scene-referred workflow.
- Shortcuts can now be directed to the currently-focused processing module instance instead of the currently-expanded one.
- The control of the lighttable view has been improved by ensuring the up/down and left/right keys have the expected behavior.
- Apply a blur when color picking in area mode. This ensures that color picker measurements aren't overly influenced by image noise. This change particularly improves the stability of filmic's black relative exposure measurement.
- Add support for DNG GainMap EXIF information and update the pixel gain in raw-prepare module. This gives a better initial exposure to the imported DNG pictures.

Fixed:
- Check for total memory on Linux is now more portable
- MIDI buttons with light status are now properly updated
- Tab shortcut tooltips are correctly displayed on tabbed modules
- Misalignments between source and target patches in the retouch module have been resolved. "Jumpy" movements are also improved when adjusting nodes or segments.
- The start of culling mode is improved, especially where no images are selected and/or under the mouse
- Local-copy status icon position fixed in block overlay
- Crop handle positions fixed when using fast movements
- RCD OpenCL tiling issues resolved
- Tile stitching for X-Trans sensors
- Filmstrip update fixed if crop is left open when moving to next image
- "collections" module now correctly updated when new images are imported
- Landscape/portrait print handling was broken due to a recent CUPS change. We now rely on the CUPS filter for the proper orientation.
- Fixed possible PDF corruption in export and print modules due to duplicate written byte count
- Fixed a possible race conditions in retouch and color reconstruction OpenCL code making darktable crash
- Properly transform points for the rotation computation in perspective correction. This fixes an issue when the image is flipped making it impossible to use the rotation control.
- Removed RatingPercent in EXIF data as it is not standardized and can confuse the Windows image viewer

Fixed label/reject behavior when multiple images are selected:
- When attempting to reject multiple images, they will now be set to rejected if any of them are not currently rejected. They will be set to un-rejected if all of them are currently rejected.
- This allows for more predictable handling of images with inconsistent reject statuses
- Similar changes have also been made when toggling color labels on/off
- Fixed white balance preset lookup in the "white balance" module
- Fixed some possible missing refresh of the metadata editor
- Fixed possible translation issue on Windows