Dust & Scratch Healing
Dust and scratches, gone with a swipe
Dust, hairs and scratches are the most tedious part of film digitization. NegRGB offers four weapons — hold-Ctrl quick healing, Ctrl+Alt straight-line scratch repair, rubber-band auto detection, and whole-frame infrared detection — backed by GPU-accelerated fill algorithms and a reviewable stroke list, turning cleanup from a chore into a gesture.
Highlights
- —Hold Ctrl: click for spots, drag for scratches, wheel resizes the brush
- —Hold Ctrl+Alt and click both ends to heal a whole straight scratch in one stroke
- —Rubber-band auto detection with adjustable sensitivity — accept one by one or heal all
- —Dark-defect polarity matches scan-time dust; edge and grain false hits suppressed
- —Infrared whole-frame detection catches sharp specks and soft defocused blobs alike
- —GPU fill matches surrounding texture; full-res healing runs in the background
- —Heals anchor to the film's physical defects — crop and rotate, they stay aligned
- —Reviewable stroke list: delete one or clear all, fully undoable
Four ways to heal
Quick healing: hold Ctrl in edit mode and the cursor becomes a round brush — click to heal a spot, drag to heal a scratch, release to apply, with full-resolution healing finishing in the background. Straight-line repair: hold Ctrl+Alt and click once to anchor one end of the scratch (a yellow anchor circle that survives zoom-mode switches), then click the other end to heal the whole long scratch along a straight line — ESC cancels at any time. Rubber-band detection: drag a rectangle and dust and scratches inside are detected automatically — left-click to accept, right-click to dismiss, "heal all" clears the batch; the box itself can be moved, resized and rotated to re-detect, and the sensitivity slider re-analyzes on the fly; hold the left button to temporarily hide the candidate markers for a before/after look, and batch healing shows a background progress card at the bottom of the preview.
Infrared detection (RGBI scans)
In RGBI four-channel TIFFs from tools like VueScan, dust and scratches show up as dark defects in the infrared channel. Infrared detection runs a dedicated dual-scale algorithm across the whole photo: sharp specks and fine scratches as well as soft, defocused blotches; progress is cancellable, and hovering the button transiently shows the IR grayscale so you can verify defect positions by eye. Each candidate's brush auto-fits the defect's measured size, and already-healed defects are filtered out of repeat runs.
Healing you can review
All healed strokes live in the dust panel list, newest first, highlighting their position on hover; any single stroke can be deleted. Review mode switches the preview to the un-healed original with all markers overlaid, so misses and over-heals are obvious; before clearing everything you can hover to preview the photo with no healing at all. Heal positions bind to the film's physical defects — crop or rotate the photo later and they stay aligned. Strokes persist per photo, with undo/redo throughout.