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AI Models

Understanding the AI Models

Nostalgia uses multiple specialized AI models. Here's what each one does, when the pipeline selects it, and what to expect.

How Model Selection Works

When you upload a photo, the diagnosis step identifies damage types, color mode, face detection, and scan quality. Based on this analysis, the pipeline builds a recipe — an ordered sequence of AI tools — and selects the best model for each step automatically.

You choose the tools (restore, colorize, enhance). The system picks the best model. You do not need to know which model is running — the pipeline handles this transparently.

Restoration

Fix scratches, tears, fading, and age wear.

ModelBest ForNotes
Scene Restore (default)Most photosBalanced scene-level repair tuned for restraint. Handles scratches, tears, fading, and contrast recovery across the full image. Default for most restoration jobs.
Face Restore (CodeFormer)Damaged portraitsMore aggressive face reconstruction. Best on portraits with moderate damage. May over-reconstruct very small or severely damaged faces — always compare before/after on faces.
Face Restore (GFPGAN)Well-preserved portraitsGentler face restoration. Produces subtle improvements most visible when zooming in at full resolution. Better choice when faces are not heavily damaged.
Scene Restore (default)Most photos

Balanced scene-level repair tuned for restraint. Handles scratches, tears, fading, and contrast recovery across the full image. Default for most restoration jobs.

Face Restore (CodeFormer)Damaged portraits

More aggressive face reconstruction. Best on portraits with moderate damage. May over-reconstruct very small or severely damaged faces — always compare before/after on faces.

Face Restore (GFPGAN)Well-preserved portraits

Gentler face restoration. Produces subtle improvements most visible when zooming in at full resolution. Better choice when faces are not heavily damaged.

Colorization

Add natural color to black-and-white photos.

ModelBest ForNotes
DDColor (default)Most B&W photosBalanced colorizer with natural-looking results. Works best on outdoor scenes, portraits, and group photos. May occasionally produce muted colors — re-run if the result looks off.
DeOldifyComparison fallbackEconomical alternative colorizer. More saturated but less accurate than DDColor. Useful for comparing different color interpretations of the same photo.
DDColor (default)Most B&W photos

Balanced colorizer with natural-looking results. Works best on outdoor scenes, portraits, and group photos. May occasionally produce muted colors — re-run if the result looks off.

DeOldifyComparison fallback

Economical alternative colorizer. More saturated but less accurate than DDColor. Useful for comparing different color interpretations of the same photo.

Enhancement

Sharpen and upscale to 2x resolution.

ModelBest ForNotes
Real-ESRGANLow-resolution scans2x super-resolution that recovers fine detail from small prints and low-quality scans. Apply as the final step. Does not work on grayscale — colorize B&W photos first.
Real-ESRGANLow-resolution scans

2x super-resolution that recovers fine detail from small prints and low-quality scans. Apply as the final step. Does not work on grayscale — colorize B&W photos first.

Deblur

Remove motion blur and camera shake.

ModelBest ForNotes
NAFNetPhone captures, photos-of-photosRemoves motion blur and softness from handheld captures. Run as the first step before other tools. If you can rescan on a flatbed, that will always produce better results.
NAFNetPhone captures, photos-of-photos

Removes motion blur and softness from handheld captures. Run as the first step before other tools. If you can rescan on a flatbed, that will always produce better results.

Deglare

Reduce glare from glossy prints and glass frames.

ModelBest ForNotes
Composite DeglareMild to moderate glareSingle-frame glare reduction. Works when underlying detail is partially visible through glare. For heavy glare, rescanning with indirect light or Google PhotoScan is more effective.
Composite DeglareMild to moderate glare

Single-frame glare reduction. Works when underlying detail is partially visible through glare. For heavy glare, rescanning with indirect light or Google PhotoScan is more effective.

Animation

Generate subtle motion from still portraits.

ModelBest ForNotes
MiniMax LiveClear, well-restored portraitsCreates subtle animation from still images. Highest-cost operation — uses separate animation credits. Best applied to portraits that already look trustworthy as stills.
MiniMax LiveClear, well-restored portraits

Creates subtle animation from still images. Highest-cost operation — uses separate animation credits. Best applied to portraits that already look trustworthy as stills.

AI Captions & Stories

Generate descriptions, narratives, and date estimates.

ModelBest ForNotes
Claude (Anthropic)All restored photosWrites warm, personal captions and narrative stories. Can estimate photo dates from visual cues. Review generated text before publishing — AI may misidentify details.
Claude (Anthropic)All restored photos

Writes warm, personal captions and narrative stories. Can estimate photo dates from visual cues. Review generated text before publishing — AI may misidentify details.

Known Failure Modes

AI restoration is powerful but not infallible. Here are the scenarios where models struggle or do not work, and what to do instead.

ScenarioToolSeverityAdvice
Daguerreotypes & platesRestoreDoes not workSeek professional conservation
Heavy emulsion liftingRestorePoor resultsMissing emulsion = missing data
Grayscale inputEnhanceDoes not workColorize first, then enhance
Very small facesFace EnhanceMay hallucinateCompare before/after carefully
Heavy glare (washed out)DeglareLimited resultsRescan with indirect light
Original camera blurDeblurLimited resultsRescan on flatbed if possible
Muted colorsColorizeInconsistentRe-run colorization, or try a different photo crop
Daguerreotypes & platesDoes not work
ToolRestore

Seek professional conservation

Heavy emulsion liftingPoor results
ToolRestore

Missing emulsion = missing data

Grayscale inputDoes not work
ToolEnhance

Colorize first, then enhance

Very small facesMay hallucinate
ToolFace Enhance

Compare before/after carefully

Heavy glare (washed out)Limited results
ToolDeglare

Rescan with indirect light

Original camera blurLimited results
ToolDeblur

Rescan on flatbed if possible

Muted colorsInconsistent
ToolColorize

Re-run colorization, or try a different photo crop

See the AI in action

All this technology works behind the scenes. You just upload a photo and get a result.