Luma

Luma is a native macOS photo-editing prototype built with SwiftUI and Core Image.

The goal is a fast local editor for browsing photos, making common non-destructive adjustments, applying simple portrait retouching, and exporting edited JPEG, HEIC, PNG, or TIFF files without sending images to a server.

What Works

Library

• Import local photos and folders.
• Drag photos or folders into the workspace to import them.
• Click the empty workspace to open the system file picker.
• Restore the local catalog across launches.
• Load photo metadata, histograms, and thumbnails in the background so importing and restoring large libraries stays responsive.
• Browse thumbnails and preview the selected photo.
• Adjust the thumbnail grid size from the library sidebar.
• Keep thumbnail cells stable while showing rating and flag state.
• Move to the previous or next visible photo from the toolbar or keyboard.
• Jump to the first or last visible photo from the Photo menu.
• Search by filename, camera, lens, format, and common exposure metadata.
• Sort by file name, capture date, rating, flag, color label, file size, format, camera, lens, or import date.
• Reverse the current library sort order.
• Filter by picked, rejected, rated, unrated, unflagged, labeled, unlabeled, individual color labels, recent imports, RAW, non-RAW, edited, unedited, and minimum star rating.
• Clear active library filters in one action.
• Hide rejected photos during everyday browsing.
• Keep the preview selection aligned with the visible library filter.
• Clear in-memory image caches when needed.
• Rate photos from zero to five stars.
• Use number keys 0-5 to clear or set the selected photo rating.
• Mark photos as picked or rejected.
• Add color labels and use number keys 6-9 for red, yellow, green, and blue labels.
• Clear rating, flag, and color label from the selected photo in one action.
• Sync the selected rating and color label to all picked photos.
• Remove photos from the local catalog without deleting the original file.
• Remove all rejected photos from the local catalog without deleting original files.
• Reveal the selected original file in Finder.
• Copy the selected original file path to the clipboard.
• Create virtual copies for alternate edits without duplicating the original image file.

Editing

• Non-destructive adjustment model.
• Before and after comparison.
• Side-by-side original and edited comparison.
• Luminance and RGB histogram display.
• Fit, 100 percent, zoom in, and zoom out controls in the preview.
• Highlight clipped shadows and highlights in the preview.
• Undo and redo for adjustment changes.
• Collapse advanced adjustment panel sections.
• In-memory preview caching for repeated renders.
• Keep the current preview on screen while edits re-render, showing a small progress indicator instead of a full-screen spinner.
• In-memory thumbnail caching for smoother library browsing.
• Rotate left and right.
• Flip photos horizontally or vertically.
• Straighten.
• Vertical and horizontal perspective transform controls.
• Crop to common aspect ratios, including square, portrait, classic photo, and wide formats.
• Adjust the crop framing position after choosing a fixed aspect ratio.
• Reset crop framing, straighten, and rotation without changing tone edits.
• Apply built-in presets for vivid color, landscapes, portraits, black and white, warm film, and matte film.
• Apply one-click Auto Enhance.
• Apply a one-click black and white look from the panel or Photo menu.
• Copy and paste adjustments between photos.
• Sync the current adjustments to all picked photos.
• Reset the selected photo adjustments from the Photo menu or keyboard.
• Reset tone adjustments without changing crop, local, or retouching edits.
• Apply a built-in preset to all picked photos.
• Reset adjustments on all picked photos.
• Inspect a luminance histogram.

Lens Corrections

• Lens distortion correction for mild barrel or pincushion adjustment.
• Defringe control for reducing color fringing on high-contrast edges.
• Lens vignette correction for brightening dark corners.
• Reset lens corrections without changing crop, tone, local, or retouching edits.

Light And Color

• Exposure.
• Highlights.
• Shadows.
• Whites.
• Blacks.
• Contrast.
• Saturation.
• Hue.
• Warmth.
• Tint.
• Vibrance.
• Fade for matte black-point lift.
• Texture.
• Clarity.
• Dehaze.
• Noise reduction.
• Sharpness.
• Vignette with radius control.
• Film grain with amount, size, and roughness controls.
• Tone curve controls for shadows, darks, lights, and highlights.
• Color grading for shadows, midtones, and highlights with balance control.
• Radial local exposure, saturation, and warmth with center, radius, and feather controls.
• Linear gradient exposure, saturation, and warmth with start and end controls.
• Invert radial and linear local masks.
• Flip linear gradient direction without changing the exposure amount.
• Reset radial and linear local adjustments independently.
• Multi-point spot healing with source offset, radius, feather, and strength controls.
• Add, select, delete, and reset spot-heal points.
• Click the preview image to place a selected spot-heal point directly on the photo.
• Reset local adjustments without changing global edits.
• HSL Color Mixer controls for red, orange, yellow, green, aqua, blue, purple, and magenta.
• Reset color mixer channels without changing other edits.

Portrait Retouching

• One-click Auto Beauty.
• Skin smoothing.
• Wrinkle softening.
• Blemish fading.
• Whitening.
• Rosy tone.
• Brightening.
• Skin warmth.
• Glow.
• Softening.
• Detail.
• Eye enlargement using face detection when eye landmarks are available.
• Face slimming using face detection.
• Body slimming with a simple center-weighted distortion.
• Reset beauty adjustments without changing other edits.

Metadata And Export

• View basic file information.
• Inspect common EXIF fields such as camera, lens, exposure, focal length, and capture time.
• Identify system-readable RAW files with a RAW badge and filter RAW or non-RAW images.
• Render and export in a color-managed sRGB space, so exported files are correctly tagged and match the on-screen preview.
• Export the selected edited photo as JPEG, HEIC, PNG, or TIFF.
• Apply export presets for full-size, large web, social, and thumbnail output.
• Choose JPEG or HEIC quality.
• Resize exports by long edge.
• Apply output sharpening after export resizing.
• Add a text watermark during export.
• Choose whether exported filenames get a custom suffix.
• Reset export settings to the default JPEG output.
• Batch export all picked photos as JPEG, HEIC, PNG, or TIFF.

Run

Open the package in Xcode:

open Package.swift

Or build it from the command line:

swift build

Run tests from the command line:

swift test

Current Limits

• RAW support depends on what macOS ImageIO and Core Image can decode on the current machine.
• RAW files are decoded through the Core Image RAW pipeline (CIRAWFilter), which handles demosaicing. Luma does not yet expose camera-profile, lens-correction, or wide-gamut controls, and the working and output space is sRGB rather than a full ICC color-management pipeline.
• Portrait retouching is simple Core Image based processing. It is useful for quick edits, but it is not yet a semantic face/body retouching engine.
• Healing and masking are still early, and brush-based retouching is not complete yet.
• Preview and thumbnail caching are in memory only. Very large libraries and large RAW files still need disk-backed caching and more scheduling work.

Next Work

• More local adjustment mask types.
• Brush and more gradient tools.
• Brush-based healing and spot removal.
• Disk-backed preview and thumbnail cache for very large libraries.
• More complete RAW and color pipeline, including camera profiles, lens correction, and wide-gamut output.