Glossary

This glossary covers terms that are specific to RapidRAW or that appear in the UI in a non-standard way. General photography terms (exposure, ISO, white balance, contrast) are not redefined; those are universal.

.rrdata

The sidecar file that stores all of your non-destructive edits for a photo. JSON format, typically a few kilobytes. Created automatically the first time you adjust a photo and lives next to the original (IMG_2231.NEF.rrdata). One per original plus one per virtual copy. See Importing Photos.

.rrexif

A companion sidecar that preserves EXIF metadata when RapidRAW produces a new pixel file (denoise, panorama stitch, HDR merge, negative convert). Without it, the camera metadata of the source images would be lost.

AgX

A film-emulation tone mapper (one of two options for the Tone Mapper in Adjustments → Basic). Produces smoother highlight roll-off and a slightly more contrasty midtone than the Basic tone mapper. See Basic → Tone Mapper.

AI Subject / Sky / Foreground / Depth

The four AI-generated mask types. Each runs a neural-network model on the CPU to identify a region. Depth uses the Depth Anything v2 model. See Masks → AI-generated.

AppImage

A self-contained Linux executable format used for the RapidRAW Linux distribution. Make it executable with chmod +x, then run directly. See Installation → Linux.

Backend

The graphics API RapidRAW renders through. Picked automatically by WGPU, or set manually in Settings → Processing → Backend to Auto, Vulkan, DirectX 12, Metal, or OpenGL. Switching backends is the most common fix for canvas rendering issues. See GPU & Drivers.

Basic (panel)

The first group in the Adjustments panel. Holds Tone Mapper, Exposure, and the six tonal sliders (Brightness, Contrast, Highlights, Shadows, Whites, Blacks). See Basic.

Basic (tone mapper)

The non-AgX Tone Mapper option. A standard tone curve with conservative roll-off, similar to a "neutral" camera profile. See Basic → Tone Mapper.

Centré

A center-weighted detail enhancement slider in Detail → Presence. Applies more of the local-contrast effect to the image center, fading toward the edges. Not available in masks. See Detail → Presence.

Color Calibration

A primaries-level adjustment that shifts Red, Green, and Blue independently in hue and saturation, plus a Shadows Tint. Applied very early in the pipeline (think: per-camera profile). Not available in masks. Not included in Copy & Paste settings. See Color → Color Calibration.

dnglab

The open-source Rust library RapidRAW uses for RAW decoding. Repo: dnglab/dnglab. When a camera RAW isn't supported, the upstream issue belongs at dnglab first; see File Formats → What to do if your camera isn't supported.

Flow mask

A brush-style mask that simulates fluid pressure for organic painting. Like a Brush mask but with pressure-aware rasterization. See Masks → Painted.

Halation

A film-emulation effect that adds a warm bloom around very bright highlights, emulating how color film overflows red/orange around overexposed regions. See Effects → Creative.

Lensfun

The open-source lens-correction database embedded in RapidRAW. Used by the Crop & Geometry → Lens Correction panel to apply automatic distortion, vignette, and TCA corrections based on the lens reported in EXIF. New lens profiles are added at the lensfun project.

LUT

Lookup Table; a 3D color mapping. RapidRAW reads .cube, .3dl, and Hald-CLUT image files (.png, .jpg, .tiff). Applied as one of the final steps of the Effects pipeline. See Effects → LUT.

Quick Eraser

A LaMa-based AI inpainting tool that removes painted-over objects in seconds. Combines AI subject segmentation with the LaMa inpainter. Lives in the AI panel (K). See Inpainting → Quick Erase.

Region of Interest (ROI)

An internal rendering optimization. When you zoom in, RapidRAW only renders the visible portion at full resolution, keeping panning fast on large RAW files. You won't see this directly; you'll just notice the editor stays smooth at high zoom levels.

Submask

A single layer within a mask container. Each mask has one or more submasks combined via Additive, Subtractive, or Intersect modes. See Masks → How masks are organized.

Tone Mapper

The first stage of RapidRAW's tone pipeline; converts linear scene-referred RAW data to a display-referred image. Two options: Basic and AgX. See Basic → Tone Mapper.

Virtual copy

A second (or third…) edit of the same photo without duplicating the underlying RAW file. Each virtual copy is its own .rrdata sidecar alongside the original. See Virtual Copies.

WGSL

WebGPU Shading Language; the shader language RapidRAW uses for its GPU rendering pipeline. You don't interact with WGSL as a user; it's named here so you understand what people mean when they reference RapidRAW's "shaders." Source files live in src-tauri/src/shaders/.