LR-PREF-DISPLAY: on Linux, previews use the display profile from colord

While no monitor profile is chosen, the Linux app reads the profile the
desktop assigns to the display in colord (org.freedesktop.ColorManager,
system bus, via zbus) on a background thread every 3 s, and shows
previews through it. With several displays it is used only when they all
share one profile; without colord the view stays sRGB. Windows' WCS
needs FFI and stays manual. Also satisfies clippy 1.99's
chunks_exact_to_as_chunks in spots.rs.

Sources: the colord D-Bus API documentation; own design.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

apps/lightcraft/src/colord.rs

@@ -0,0 +1,125 @@
+//! The ICC profile the desktop assigns to the display (Linux, through colord).
+//!
+//! GNOME, KDE and most other desktops keep each monitor's profile in colord
+//! (`org.freedesktop.ColorManager` on the system bus): Settings ▸ Color writes it there, and a
+//! calibrator (DisplayCAL, gnome-color-manager) installs its profile there. While no monitor profile
+//! is chosen in Settings ▸ Display, previews are shown through that profile
+//! (`Services::screen_profile`). A background thread asks colord every few seconds, so the UI never
+//! waits on D-Bus; without colord, or a display with no profile, the previews stay sRGB.
+//!
+//! With several displays, the window's own one isn't known here (eframe doesn't say which monitor a
+//! window is on), so the profile is used only when every display that has one has the same: a
+//! mixed set stays sRGB rather than guess.
+
+use std::sync::{Arc, Mutex, PoisonError};
+use std::time::Duration;
+
+/// How often colord is asked again (a profile change in the desktop's settings shows within this).
+const POLL: Duration = Duration::from_secs(3);
+/// A wait before trying again when colord isn't there (not installed, no system bus).
+const RETRY: Duration = Duration::from_secs(30);
+/// The largest profile file read (real display profiles are a few KiB to a few MiB).
+const MAX_PROFILE: u64 = 16 << 20;
+
+const SERVICE: &str = "org.freedesktop.ColorManager";
+const DEVICE: &str = "org.freedesktop.ColorManager.Device";
+const PROFILE: &str = "org.freedesktop.ColorManager.Profile";
+
+/// Start the background reader and return the service the UI polls (`Services::screen_profile`).
+pub fn service() -> Box<dyn FnMut() -> Option<Vec<u8>>> {
+    let shared: Arc<Mutex<Option<Vec<u8>>>> = Arc::new(Mutex::new(None));
+    let writer = Arc::clone(&shared);
+    let spawned = std::thread::Builder::new().name("colord".into()).spawn(move || {
+        loop {
+            let wait = match connect() {
+                Some(conn) => {
+                    let icc = read(&conn);
+                    *writer.lock().unwrap_or_else(PoisonError::into_inner) = icc;
+                    POLL
+                }
+                None => RETRY,
+            };
+            std::thread::sleep(wait);
+            // the app is gone: nobody reads the profile any more
+            if Arc::strong_count(&writer) == 1 {
+                return;
+            }
+        }
+    });
+    if let Err(e) = spawned {
+        log::warn!("screen profile: no colord reader: {e}");
+    }
+    Box::new(move || shared.lock().unwrap_or_else(PoisonError::into_inner).clone())
+}
+
+fn connect() -> Option<zbus::blocking::Connection> {
+    zbus::blocking::connection::Builder::system().ok()?.method_timeout(Duration::from_secs(2)).build().ok()
+}
+
+/// The profile colord assigns to the displays, as file bytes (see the module notes for several displays).
+fn read(conn: &zbus::blocking::Connection) -> Option<Vec<u8>> {
+    let manager = zbus::blocking::Proxy::new(conn, SERVICE, "/org/freedesktop/ColorManager", SERVICE).ok()?;
+    let devices: Vec<zbus::zvariant::OwnedObjectPath> = manager.call("GetDevicesByKind", &("display",)).ok()?;
+    let mut files = Vec::new();
+    for device in devices.iter().take(64) {
+        let Some(proxy) = zbus::blocking::Proxy::new(conn, SERVICE, device.as_str(), DEVICE).ok() else { continue };
+        let profiles: Vec<zbus::zvariant::OwnedObjectPath> = proxy.get_property("Profiles").unwrap_or_default();
+        // colord lists a device's profiles default first
+        let Some(first) = profiles.first() else { continue };
+        let Some(profile) = zbus::blocking::Proxy::new(conn, SERVICE, first.as_str(), PROFILE).ok() else { continue };
+        if let Ok(file) = profile.get_property::<String>("Filename") {
+            files.push(file);
+        }
+    }
+    let file = pick(&files)?;
+    load(std::path::Path::new(file))
+}
+
+/// The profile to use for these displays' profile files: the one they share, `None` with none or
+/// with different ones (empty names are ignored).
+fn pick(files: &[String]) -> Option<&str> {
+    let mut named = files.iter().map(String::as_str).filter(|f| !f.is_empty());
+    let first = named.next()?;
+    named.all(|f| f == first).then_some(first)
+}
+
+/// The bytes of profile file `path`, `None` when it can't be read or is implausibly large.
+fn load(path: &std::path::Path) -> Option<Vec<u8>> {
+    use std::io::Read as _;
+    let file = std::fs::File::open(path).ok()?;
+    let mut bytes = Vec::new();
+    file.take(MAX_PROFILE + 1).read_to_end(&mut bytes).ok()?;
+    (!bytes.is_empty() && bytes.len() as u64 <= MAX_PROFILE).then_some(bytes)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn one_shared_profile_is_used_and_a_mixed_set_is_not() {
+        let s = |v: &[&str]| v.iter().map(|f| f.to_string()).collect::<Vec<_>>();
+        assert_eq!(pick(&s(&[])), None);
+        assert_eq!(pick(&s(&["/a.icc"])), Some("/a.icc"));
+        assert_eq!(pick(&s(&["/a.icc", "", "/a.icc"])), Some("/a.icc"));
+        assert_eq!(pick(&s(&["/a.icc", "/b.icc"])), None, "which one the window is on isn't known");
+        assert_eq!(pick(&s(&[""])), None);
+    }
+
+    #[test]
+    fn profile_files_are_read_with_a_size_cap() {
+        let dir = std::env::temp_dir().join(format!("colord-test-{}", std::process::id()));
+        std::fs::create_dir_all(&dir).unwrap();
+        let small = dir.join("small.icc");
+        std::fs::write(&small, b"acsp").unwrap();
+        assert_eq!(load(&small).as_deref(), Some(&b"acsp"[..]));
+        let empty = dir.join("empty.icc");
+        std::fs::write(&empty, b"").unwrap();
+        assert_eq!(load(&empty), None);
+        assert_eq!(load(&dir.join("missing.icc")), None);
+        let big = dir.join("big.icc");
+        std::fs::File::create(&big).unwrap().set_len(MAX_PROFILE + 1).unwrap();
+        assert_eq!(load(&big), None);
+        std::fs::remove_dir_all(&dir).unwrap();
+    }
+}

apps/lightcraft/src/main.rs

@@ -24,6 +24,8 @@
 
 mod alloc_release;
 mod appearance;
+#[cfg(target_os = "linux")]
+mod colord;
 mod control_server;
 mod dialog_filter;
 mod editors;
@@ -525,7 +527,10 @@ fn services(cc: &eframe::CreationContext<'_>, log_file: Option<&std::path::Path>
         // macOS doesn't colour-manage the window: previews follow the screen's profile (#787)
         #[cfg(target_os = "macos")]
         screen_profile: Some(Box::new(screen_profile::icc)),
-        #[cfg(not(target_os = "macos"))]
+        // Linux: the profile the desktop assigns in colord, read off the UI thread
+        #[cfg(target_os = "linux")]
+        screen_profile: Some(colord::service()),
+        #[cfg(not(any(target_os = "macos", target_os = "linux")))]
         screen_profile: None,
         pick_display_profile: Some(Box::new(|| {
             let mut d = file_dialog()

crates/pipeline/src/spots.rs

@@ -247,8 +247,8 @@ fn fill_box(src: &mut [[f32; 3]], tgt: &[[f32; 3]], alpha: &[f32], bw: usize, bh
     let flat: Vec<f32> = tgt.iter().flatten().copied().collect();
     let out = lightcraft_inpaint::complete(bw, bh, 3, &flat, &hole, &lightcraft_inpaint::CompleteParams::default())
         .unwrap_or_else(|| lightcraft_inpaint::membrane_fill(bw, bh, 3, &flat, &hole));
-    for (d, v) in src.iter_mut().zip(out.chunks_exact(3)) {
-        *d = [v[0], v[1], v[2]];
+    for (d, v) in src.iter_mut().zip(out.as_chunks::<3>().0) {
+        *d = *v;
     }
 }
 

docs/display-profiles.md

@@ -8,17 +8,25 @@ colour-manage LightCraft's window (wgpu leaves its Metal layer without a colour
 unmatched), so on a P3 screen previews used to look more saturated than the exported files in Preview or Photos (issue
 #787). The profile is read again about once a second, so moving the window to another screen is followed.
 
+**Linux uses the profile the desktop assigns in colord** (GNOME / KDE Settings ▸ Color, or a calibrator such as
+DisplayCAL) while none is chosen. A background thread asks colord (`org.freedesktop.ColorManager` on the system bus)
+every 3 s, so the UI never waits on D-Bus, and a profile change in the desktop's settings shows within that. eframe
+doesn't say which monitor the window is on, so with several displays the profile is used only when all of them that
+have one share it; otherwise, and without colord, previews stay sRGB (choose a profile by hand then). A compositor
+that colour-manages windows itself with the same profile (KWin with an ICC profile set in Display Configuration)
+would correct twice; KWin keeps that profile in its own settings, not colord, so this only happens when both are set.
+
 ## Using it
 
 Settings ▸ Display ▸ **Choose Profile…** picks an `.icc` / `.icm` file (the dialog opens where the system keeps
 them: `~/.local/share/icc` on Linux, ColorSync's folders on macOS, `…\spool\drivers\color` on Windows). **Use sRGB**
-(on macOS **Use Screen Profile**) goes back to no profile. The choice is an app setting (`ui.json`, `displayProfile`)
+(on macOS and Linux **Use Screen Profile**) goes back to no profile. The choice is an app setting (`ui.json`, `displayProfile`)
 and applies at once; a file that can't be used is reported there and previews stay sRGB.
 
 Agents and scripts: `app.displayProfile {"path": "/path/to/monitor.icc"}` (`""` or `null`: none; no `path`: report
 only) returns `{path, description, kind: "matrix" | "lut", primaries: {red, green, blue: [x, y]}}`; the screen's
-profile (macOS, none chosen) reports `path: null, screen: true`. Hosts supply it as `Services::screen_profile`
-(`apps/lightcraft/src/screen_profile.rs`); headless sessions have none and stay sRGB.
+profile (macOS or Linux, none chosen) reports `path: null, screen: true`. Hosts supply it as `Services::screen_profile`
+(`apps/lightcraft/src/screen_profile.rs`, `apps/lightcraft/src/colord.rs`); headless sessions have none and stay sRGB.
 
 ## How it works
 
@@ -47,5 +55,5 @@ LUT-based profile's correction about 65 ms. Drafts during slider drags skip the
 
 ## Not yet
 
-- Picking up the profile the operating system assigns on Linux and Windows (X11 `_ICC_PROFILE`, colord, WCS) and
-  following the window across monitors there (macOS does both, above).
+- Picking up the profile Windows assigns (WCS: needs FFI, so an isolated `unsafe` helper crate) and X11's
+  `_ICC_PROFILE`; following the window across monitors on Linux and Windows (macOS does both, above).

docs/gaps.md

@@ -1,6 +1,6 @@
 # Gaps: where LightCraft falls short of Lightroom
 
-> **Last reviewed:** 2026-10-11 · **Last updated:** 2026-10-11 · **Change:** minor (CR3 entry names the EOS R7 C-RAW fix and the refused CRX variants; CI and Windows / Linux entries note the 0.6.0 riscv64 build; camera colour: tone curve from black-and-white camera JPEGs; Compare and Reference get sharp zoom windows; gap 4 shrinks; gap 14: the HDR switch is read from crs XMP; gaps 2 and 10: EOS R5 Mark II CR3 verified) · **Target:** Adobe Lightroom Classic 15.5 / Lightroom 9.6
+> **Last reviewed:** 2026-10-11 · **Last updated:** 2026-10-12 · **Change:** minor (gap 22: Linux reads the colord display profile); previously minor (CR3 entry names the EOS R7 C-RAW fix and the refused CRX variants; CI and Windows / Linux entries note the 0.6.0 riscv64 build; camera colour: tone curve from black-and-white camera JPEGs; Compare and Reference get sharp zoom windows; gap 4 shrinks; gap 14: the HDR switch is read from crs XMP; gaps 2 and 10: EOS R5 Mark II CR3 verified) · **Target:** Adobe Lightroom Classic 15.5 / Lightroom 9.6
 
 Every known shortfall, one entry each, ranked by user impact (how many Lightroom users hit it, and
 how hard it blocks them), then by effort. **Agents pick work from the top** (the first entry nobody is
@@ -36,7 +36,7 @@ Hours are Opus 5.5 agent wall-clock hours (see [target-app-parity.md](target-app
 | 19 | **Plug-in ecosystem**: no Lightroom SDK equivalent (export / publish plug-ins, metadata plug-ins) | ⬜ | pro workflows built on plug-ins (LR/Enfuse, Jeffrey's exporters, Negative Lab Pro) | 40–80 + owner decision | [target-app-parity](target-app-parity.md#by-dimension) |
 | 20 | **Long-tail raw formats**: compressed SRW, ARQ pixel shift, IIQ, Hasselblad compression, X3F, CRW, MRW, ERF, KDC, DCR, MEF, GPR, old FinePix | raw-parity.md | small user share each | 45–85 | [raw-parity](raw-parity.md) |
 | 21 | **Localization**: 9 of 15 shipped languages partial (74–99% of catalog messages), lower-layer errors English; Hindi, Arabic, Indonesian, Korean, Vietnamese absent; no RTL or complex shaping | measured from catalogs | non-English users see mixed English | 55–90 (shipped to full); 145–255 (five new) | [localization-parity](localization-parity.md) |
-| 22 | **Pen pressure**, OS monitor profiles, follow-window colour | hardware-parity.md | brush users with tablets; multi-monitor setups | 11–22 | [hardware-parity](hardware-parity.md) |
+| 22 | **Pen pressure**, OS monitor profiles on Windows (Linux reads colord's, macOS the screen's), follow-window colour on Linux / Windows | hardware-parity.md | brush users with tablets; multi-monitor setups | 11–22 | [hardware-parity](hardware-parity.md) |
 | 23 | **Accessibility** audit with screen readers; canvas tools keyboard-reachable | LR-BEHAV-ACCESS 🟡 | blind and low-vision users | 10–20 | [ui-parity](ui-parity.md) |
 | 24 | **Brush live preview and masking feel** (#517, #518); Feather / Edge mask refinement (15.5) | issues | masking feels slower than Lightroom | 8–12 | [ui-parity](ui-parity.md) |
 | 25 | **File writes**: lossy DNG, Render to DNG; AVIF import (PSD export landed with Edit in PhotoCraft, #953) | file-format-parity.md | interchange edge cases | 21–37 | [file-format-parity](file-format-parity.md) |
@@ -72,6 +72,7 @@ Beta-blocking gaps (B) total **~230–430 h**; with the stability and platform w
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-12 | minor | Gap 22: Linux previews use the display profile from colord |
 | 2026-10-11 | minor | Reviewed against main after 0.6.0: CR3 entry names the CRX variants `crx.rs` still refuses and the R7 / R6 Mark II C-RAW state (decoding, not verified, so the measured numbers don't move); CI and Windows / Linux entries note the riscv64 release build (#844); R7 fix added to Closed recently. Panel docking (UI.9, #869) closes no listed gap |
 | 2026-10-11 | minor | Camera colour entry: raws with a black-and-white camera JPEG take its tone curve (#577); gap not closed |
 | 2026-10-11 | minor | Gap 4: Compare and Reference views get zoom windows per pane (1:1 was a 2,560 px render magnified); overlays and soft proofing remain, 8–15 h → 4–8 h |

docs/hardware-parity.md

@@ -1,6 +1,6 @@
 # Hardware parity
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-10 · **Change:** major (created from the code, gpu-pipeline.md and the parity checklist) · **Target:** Adobe Lightroom Classic 15.5 / Lightroom 9.6
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-12 · **Change:** minor (monitor profile from colord on Linux); previously major (created from the code, gpu-pipeline.md and the parity checklist) · **Target:** Adobe Lightroom Classic 15.5 / Lightroom 9.6
 
 What Lightroom does with the machine's hardware, per platform, and what LightCraft does. Sources:
 [gpu-pipeline.md](gpu-pipeline.md), [display-profiles.md](display-profiles.md), [denoise.md](denoise.md),
@@ -12,7 +12,7 @@ What Lightroom does with the machine's hardware, per platform, and what LightCra
 | GPU export | ✅ | ✅ (6000 × 4000 in ~0.3 s vs ~1.2 s CPU) | ✅ | ✅ | — | ✅ (black-export fix on an Intel iGPU, #78) |
 | AI on GPU / neural engine | Metal / DirectML / Core ML, model per feature | AI denoise on GPU or CPU (setting); SAM 3 on Metal via candle; faces on CPU | CPU / GPU denoise | CPU / GPU denoise | — | 🟡 no Core ML / Neural Engine / DirectML |
 | HDR (EDR) display | ✅ (macOS EDR, Windows HDR) | ⬜ | ⬜ | ⬜ | ⬜ | ⬜ (LR-VIEW-HDR-DISPLAY) |
-| Monitor profile | automatic per display, follows the window | 🟡 picked by hand | 🟡 | 🟡 | — | 🟡 OS profile not read; no follow across monitors |
+| Monitor profile | automatic per display, follows the window | ✅ the screen's profile, followed across screens | 🟡 picked by hand (WCS needs FFI) | 🟡 colord's profile (one display, or all sharing one); no follow across monitors | — | 🟡 Windows OS profile not read; Linux per-monitor follow missing |
 | Second window / second monitor | ✅ (Classic) | ✅ (⌘F11) | ✅ | ✅ | — | ✅ (Classic secondary-window keys missing) |
 | Pen pressure / tilt (brush masks) | ✅ pressure for size / flow | ⬜ | ⬜ | ⬜ | ⬜ | ⬜ |
 | Trackpad gestures | pinch zoom, pan | ✅ pinch, two-finger pan | 🟡 (winit) | 🟡 | 🟡 | ✅ on macOS |
@@ -35,7 +35,7 @@ correctness is proven on Apple GPUs; other vendors rely on user reports.
 | Work | Hours | Needs |
 |---|---:|---|
 | HDR display (EDR on macOS, Windows HDR, Linux where possible) | 10–20 | an HDR display to verify (human) |
-| OS monitor profile, follow window across displays | 5–10 | multi-monitor setup |
+| OS monitor profile: Windows WCS (an FFI helper crate, like `crates/sysmem`), follow the window across displays on Linux | 4–8 | multi-monitor setup |
 | Pen pressure for brush masks (winit tablet events or a pure-Rust tablet layer) | 6–12 | a tablet |
 | Remaining stages on GPU (defringe, spot removal, masks) | 10–20 | |
 | Tethered capture (PTP over USB in pure Rust, Canon / Nikon / Sony first) | 25–45 | cameras (human) |
@@ -47,4 +47,5 @@ correctness is proven on Apple GPUs; other vendors rely on user reports.
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-12 | minor | Monitor profile: Linux reads the display profile from colord; macOS row reflects #787 |
 | 2026-10-10 | major | Created |

docs/parity-checklist.md

@@ -1,6 +1,6 @@
 # Lightroom parity checklist
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-11 · **Change:** minor (rapid slider entry; LR-PROF-CAMERACOLOR: tone curve from black-and-white camera JPEGs; LR-VIEW-ZOOM, LR-VIEW-COMPARE: Compare and Reference zoom windows; LR-IMP-FORMATS, LR-IMP-CAMERA-COVERAGE: EOS R5 Mark II CR3 decodes; renamed from `parity.md`; Top gaps moved to gaps.md, shortcut notes to ui-parity.md; filesystem history retry/Undo/Redo evidence; renamed from `parity.md`; Top gaps moved to gaps.md, shortcut notes to ui-parity.md) · **Target:** Adobe Lightroom Classic 15.5 / Lightroom 9.6
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-12 · **Change:** minor (LR-PREF-DISPLAY: the Linux desktop's colord profile); previously minor (rapid slider entry; LR-PROF-CAMERACOLOR: tone curve from black-and-white camera JPEGs; LR-VIEW-ZOOM, LR-VIEW-COMPARE: Compare and Reference zoom windows; LR-IMP-FORMATS, LR-IMP-CAMERA-COVERAGE: EOS R5 Mark II CR3 decodes; renamed from `parity.md`; Top gaps moved to gaps.md, shortcut notes to ui-parity.md; filesystem history retry/Undo/Redo evidence; renamed from `parity.md`; Top gaps moved to gaps.md, shortcut notes to ui-parity.md) · **Target:** Adobe Lightroom Classic 15.5 / Lightroom 9.6
 
 The measured, row-by-row checklist: one row per Lightroom feature, menu item and shortcut, what we
 have and what is missing. It answers *does the feature exist?* (feature breadth). Whether it is good
@@ -426,7 +426,7 @@ differences and missing bindings are in [ui-parity.md](ui-parity.md#shortcuts).
 | LR-PREF-LOCALSTORAGE | Storage & cache | P1 | ✅ | `cmd:library.preferences`, `cmd:library.clearPreviews`, `cmd:library.compact` | thumbnail cache size + clear in Settings → Performance; library location + Open Library… in General |
 | LR-PREF-ACCOUNT | Account | OOS | 🚫 | | |
 | LR-PREF-INTERFACE | Interface options | P1 | ✅ | `cmd:app.settings`, `cmd:view.appearance`, `cmd:view.theme` | Appearance Mode (Sync with System / Dark / Light; the top bar button cycles Auto, Light, Dark) with separate dark (Charcoal, Midnight) and light (Silver, Paper) themes previewed in cards; hover stars persist favorite themes, the appearance button context menu opens Interface settings and lists light favorites before dark favorites; filmstrip names/badges, grid badges (auto/always/never), square-grid names, navigator, info overlay |
-| LR-PREF-DISPLAY | Monitor (display) colour management | P1 | 🟡 | `cmd:app.displayProfile`, `crates/codecs/src/display.rs`, `crates/engine/src/display.rs`, `crates/ui-egui/src/panels/settings.rs`, `apps/lightcraft/src/screen_profile.rs`, `docs/display-profiles.md` | Settings ▸ Display: a monitor ICC profile (matrix/TRC exactly, LUT-based through the CMS) chosen by hand, or on macOS the profile of the screen showing the window (followed across screens, #787); the loupe, Before, Compare, hover previews and the second window render into the display's primaries (its full gamut, CPU and GPU), thumbnails and stand-ins are converted from sRGB; histogram, preview caches and exports stay sRGB; soft proofing's display gamut warning uses the display's gamut. Missing: picking up the profile the OS assigns on Linux and Windows (X11 `_ICC_PROFILE`, colord, WCS), per-monitor profiles there |
+| LR-PREF-DISPLAY | Monitor (display) colour management | P1 | 🟡 | `cmd:app.displayProfile`, `crates/codecs/src/display.rs`, `crates/engine/src/display.rs`, `crates/ui-egui/src/panels/settings.rs`, `apps/lightcraft/src/screen_profile.rs`, `apps/lightcraft/src/colord.rs`, `docs/display-profiles.md` | Settings ▸ Display: a monitor ICC profile (matrix/TRC exactly, LUT-based through the CMS) chosen by hand, or on macOS the profile of the screen showing the window (followed across screens, #787), on Linux the profile the desktop assigns in colord (read off the UI thread every 3 s; used with one display, or several sharing one profile); the loupe, Before, Compare, hover previews and the second window render into the display's primaries (its full gamut, CPU and GPU), thumbnails and stand-ins are converted from sRGB; histogram, preview caches and exports stay sRGB; soft proofing's display gamut warning uses the display's gamut. Missing: Windows' WCS profile (needs FFI, so `unsafe`), X11 `_ICC_PROFILE`, per-monitor profiles on Linux (eframe doesn't say which monitor the window is on) |
 | LR-PREF-PERFORMANCE | GPU / performance | P1 | ✅ | `cmd:app.gpu`, `cmd:app.memoryBudget`, `cmd:app.settings` | GPU on/off (a crash while the GPU device or its kernels are built, issue #250, turns it off for the next launch), preview size (Automatic = the whole-frame loupe render at canvas size, up to 2560 px; or a 1600–5120 px size for it; zoomed views add a window at up to 100 %, issue #323), memory budget (a quarter of it is the idle per-view stage caches' share; the open photo's views are counted and reported, and cut only past four times that, the before side's and the zoom window's first — a Before/After at 1:1 on a 2800 px canvas holds about 1 GB of GPU stages, plus the one 288 MB copy of the original, which `ui.inspect` reports as `sharedSourceBytes`), thumbnail cache size in Settings |
 | LR-PREF-PEOPLE | Face recognition | P2 | 🟡 | `cmd:faces.enable`, `cmd:faces.models.list`, `cmd:faces.models.inspect`, `cmd:faces.models.install`, `cmd:faces.models.download`, `cmd:faces.models.downloads`, `cmd:faces.models.downloadCancel`, `cmd:faces.models.remove`, `cmd:faces.models.select`, `cmd:dialog.faceModel`, `crates/faces/src/lib.rs`, `crates/ui-egui/src/panels/faces.rs` | Settings ▸ Faces: an off-by-default toggle and the face model list. Models are opt-in and never bundled, the 232 KB YuNet detector included. Press Download (terms first; then a pinned address, size and SHA-256 checked, fetched over pure-Rust https with `lightcraft-fetch`), or add any `.onnx` by picking or dropping it: it is recognised by hash or described from its shape, shows its licence terms and training-data note, runs a self-test, and installs only after an "I accept" box; an installed model is chosen and recognition switched on at once (the newest wins, each model keeps its own embedding cache). Non-commercial models are add-by-file only, never offered for download. Suggestions of names run on the shared pure-Rust CPU interpreter (`crates/faces/src/net.rs`, `crates/faces/src/runtime.rs`; bounded im2col/GEMM, checked ONNX shapes/operators; no external inference runtime; 40 public crops agree within 2.1e-6, one-thread SFace 34–36 ms / AuraFace 233–252 ms, see docs/faces.md) in a background worker and are never applied automatically. Thresholds are starting points calibrated on busts, not yet on live faces; the Recognise faces switch is off until a recognition model is chosen and installed (`faces.enable {enabled: true}` refuses otherwise; removing the last recogniser switches it off), issue #678 |
 | LR-PREF-WATERMARK | Watermark settings | P1 | ✅ | `cmd:export.savePreset`, `crates/ui-egui/src/panels/dialogs.rs` | set in the Export dialog; kept with Export with Previous and in saved export presets |
@@ -787,6 +787,7 @@ Latin stays upright. Advanced Japanese composition remains open. Regression cove
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-12 | minor | LR-PREF-DISPLAY: on Linux, previews follow the display profile the desktop assigns in colord |
 | 2026-10-11 | minor | KEY-SLIDER-TYPE: honor immediate Return/Escape and keep typed keys in the value editor; add regression references |
 | 2026-10-11 | minor | LR-PROF-CAMERACOLOR: raws with a black-and-white camera JPEG take its tone curve (issue #577) |
 | 2026-10-11 | minor | LR-VIEW-ZOOM and LR-VIEW-COMPARE: Compare and Reference are sharp at 1:1 (zoom windows per pane, two originals kept decoded while they are open); statuses unchanged |