photo-editing-process

name

photo-editing-process

description

The real operator know-how for getting a good edit out of the Agentic Image Editor's toolset (straighten, crop, exposure, tone, toneCurve, whiteBalance, contrast, vibrance, saturation, splitTone, dehaze, denoise, look, sharpen). The taste and judgment a working editor has internalized: how to read an image, genre-aware sensibility, the opinionated-but-collaborative stance, order of operations, target values, intent/mood translation, and the failure modes. Read this before tuning the agent's prompt or reasoning about why an edit went sideways. Keep it in lockstep with `src/server/utils/editing-guide.ts` (the token-lean version injected at runtime).

Photo Editing Process — operator's playbook

This tool's agent tunes a single non-destructive develop config — one absolute value per global slider (the same toolset, as a "preset"). Each iteration it looks at the rendered result, returns the full updated config, and the server re-renders the whole ordered stack from the original. Nothing is baked: any slider can move up or down freely with no compounding, so "a touch less contrast" is literally a smaller contrast value, not an inverse op piled on top. Geometry (straighten + crop) reframes the image; every tonal/ color slider affects the whole frame. The ONE local tool is a single linear graduated (ND) filter (gradFilter) for skies/horizons — there is no brush, no healing, no per-region color. That constraint is the whole game: the discipline is restraint, because you can't paint a fix into one corner.

The single most important thing: a good edit is 3-5 deliberate moves, not 8 fiddly ones. Most amateur edits are bad because of too much, not too little.

Stance — edit like a pro, not a slider-twiddler

The mechanics below are table stakes. What separates a real editor is judgment: deciding what the photo needs, doing the least that achieves it, and stopping. Hold these:

• The best edit is invisible. If a viewer can tell the image was edited, you went too far. The goal is "polished, not processed." The universal amateur tell is too much.
• Do the least that serves the intent. Many images need almost nothing. When torn between two amounts, pick the smaller. Restraint reads as taste; cranking reads as amateur.
• Build up from zero, don't start strong and pull back. Your eye normalizes to whatever it's looking at, so an overcooked starting point quickly reads as "fine." Push each move only until the problem is solved, then stop.
• Be opinionated, but serve the photo. The user gives natural-language intent ("make it pop," "moody," "fix it"). Find the real goal behind the words and serve that — going a touch beyond literal when that's what the intent wants — while honoring explicit requests and protecting the subject. If "make it pop" would wreck skin, do the version that reads as pop and keeps skin honest. Bring a point of view; don't just obey the literal words, and don't override them either.
• You self-compare every pass. The agent re-looks at the rendered frame with the original beside it. Use that: if the current frame screams "edited," dial back. You have no "sleep on it" — so make the before/after check the thing that tells you to stop.

The toolset (exact params — advise nothing outside this)

Op	Param(s) & range	What it does
straighten	angleDeg −45..45 (+ = clockwise)	rotate + auto-crop the borders
crop	left/top 0..1, width/height 0.1..1, aspect enum	composition / aspect crop, normalized keep-rect on the post-straighten frame (identity 0,0,1,1)
exposure	ev −3..3 stops	overall brightness (midtone anchor)
contrast	amount −1..1	true sigmoidal S-curve about mid-gray
tone	highlights −100..100, shadows −100..100	highlights<0 recovers blown highs; shadows>0 lifts/opens shadows. Independent, luminance-masked
whiteBalance	temp −100..100, tint −100..100	temp+ warmer/golden, temp− cooler/blue; tint+ magenta, tint− green
saturation	amount 0..2 (1 = none)	global, blunt color scaler
vibrance	amount −1..1	smart saturation; protects skin & already-vivid colors
look	name	named grade: goldenHour, tealOrange, noir, vintageFade, crispClean
gradFilter	enabled 0/1, angle 0..360, position 0..1, feather 0..100, exposure −3..3 EV	one linear graduated (ND) filter — darken the sky / lift the foreground. angle 0 = top/sky; exposure<0 darkens. enabled 0 = unused (the default)
sharpen	amount 0..1	output sharpening — a finishing step

Read the image BEFORE you touch it

Don't reach for a slider until you can name what's wrong. First, three judgment questions — they tell you what "good" even means for this frame:

• What is this photo, and what is it for? Name the genre and the feeling it wants. You're translating an intent, not transcribing pixels. (See Genre sense below.)
• Where should the eye land? Find the subject (portraits: the eyes). Is anything pulling attention the wrong way — a color cast, a hot highlight, a muddy corner?
• What is the single biggest problem? Triage like a doctor's intake. Name the one worst thing and fix it first; don't spread effort evenly across sliders.

Then scan the technical problems, in priority order:

1. Geometry. Is the horizon or a strong vertical tilted? Use the true horizon, a building edge, a door frame, a lamppost. A 1-2° tilt is the most common and most ignored flaw.
2. Exposure (midtones). Is the subject too dark or too bright? Judge the face, the product, the focal point — not the brightest pixel in the frame.
3. Clipping. Blown highlights = a region gone pure white with no detail (sky, forehead, a window). Blocked shadows = pure black with no texture. Tell: if a bright area still holds faint tonal variation it's recoverable; if it's flat featureless white the detail is gone forever — don't waste a tone move trying to resurrect it.
4. Color cast. Find something that should be neutral — white shirt, gray concrete, snow, paper, teeth — and read its tint. Blue = too cool (shade, overcast). Orange = too warm (tungsten/indoor). Green = fluorescent. Magenta = someone overcorrected. A cast reads as muddy, low contrast, which is why you fix it before judging contrast.
5. Flat vs contrasty. Flat: hazy, grayish, no true black, milky — common in overcast/backlit/distance shots. Contrasty: harsh, blocked shadows, clipped highlights, no midtone breathing room.
6. Skin tones. The eye is ruthless about skin. Orange or magenta skin is the #1 tell of an over-edited image. Vibrance and the tealOrange look both lean on skin — watch it.

Genre sense — "good" means something different per genre

The same move is a style in one genre and a disqualifying error in another. Read the genre first (above), then let it steer direction; the numbers stay in Target values.

Genre	Goal	Lean toward	Genre-specific tell to avoid
Portrait	Polished but human	Slightly bright; gentle contrast; lift shadows gently; vibrance not saturation; light sharpen	Plastic/over-clarity skin; orange ("pumpkin") or magenta skin; crushed eye sockets
Landscape	Believable, maximal range	exposure↑ → highlights− (hold the sky) → shadows+ (open foreground); gentle S; modest dehaze	Neon greens, cyan-clipped skies, the "HDR cartoon," milky lifted shadows
Food	Fresh, appetizing, WARM	Bright; shadows lifted generously; vibrance; slightly warm WB	Green/cool cast (reads stale/spoiled); neon "radioactive" color; over-sharpen
Product / e-commerce	Accuracy IS the job	Neutral WB; clean whites; flat-ish; even light	ANY creative grade/cast/mood; deep shadows; over-sharpen (reads "rendered")
Street / documentary	Mood and grit	Higher contrast; inky blacks on purpose; often muted color; firmer clarity	Lifting shadows to gray mud (kills the look); anything that alters meaning
Real estate / interior	Bright, even, airy, honest	exposure↑; recover blown windows (highlights−); lift shadows hard; low contrast; straight verticals	HDR halos; flat over-bright; heavy corner shadow (kills "airy")

The load-bearing splits, in one line each:

• Shadows: lift HARD (food, interior, product) · lift GENTLY (portrait, landscape) · CRUSH / never lift (street).
• Clarity / dehaze: poison for portrait & product · flavor for food & landscape · weapon for street.
• Contrast: low (product, interior, portrait) · moderate (food, landscape) · high sigmoidal (street).
• Universal: pull highlights down to protect the bright end in nearly every genre — except street, where blowing brights can be a deliberate eye-direction choice.

Order of operations (and why each precedes the next)

straighten → crop → exposure → tone → whiteBalance → contrast → vibrance (→ saturation) → look → gradFilter → sharpen

This is not arbitrary. Each step makes the next judgment readable:

• straighten first, then crop — both are geometry. straighten auto-crops the rotation borders and crop is normalized to the post-straighten frame, so level the image then compose the crop. Settle the frame before you spend moves tuning pixels you might crop away. Align straighten to the true horizon, a building vertical (wall edge, door frame, window mullion, lamppost), or a strong horizontal; prefer small angles (most tilts are 1–3°). Once a straighten or crop is applied, the agent is handed a third reference image — the current result with a rule-of-thirds alignment grid overlaid — to confirm the horizon is level / verticals are square and refine if not (color/exposure are still judged from the clean images, so the grid never pollutes those reads). Crop is for composition, not correction — tighten on the subject, cut dead space / an edge distraction, or set an aspect (1:1, 4:5, 3:2, 16:9). Don't crop reflexively; most edits keep the full frame (identity 0,0,1,1).
• exposure second — set the midtone anchor before shaping the ends. If the whole image is a stop dark, every other read (shadow detail, cast, contrast) is wrong. Exposure is the foundation; build on it.
• tone third — now that midtones sit right, recover blown highlights (highlights negative) and open blocked shadows (shadows positive). Doing this before exposure means you're fixing the ends of a tonal range whose middle is about to move.
• whiteBalance fourth — before contrast, because a color cast masquerades as low contrast and as wrong saturation. Neutralize the cast and the image often looks half the way "fixed" on its own. Judge contrast on a neutral base.
• contrast fifth — with exposure, tone, and color clean, you're now shaping a true tonal range with the S-curve, not amplifying a cast into mud.
• vibrance, then saturation — color comes after tone/contrast because contrast changes apparent saturation. Reach for vibrance first (it protects skin and already- vivid colors). saturation is the blunt instrument — usually you don't need it at all.
• look near the end — a named grade is a creative layer applied over a corrected base. Grade a clean image, not a broken one.
• sharpen LAST — sharpening amplifies whatever's there, including noise. If you sharpen before tone/contrast, you sharpen noise and then fight it with every subsequent move. It's a finishing step. Always.

Deviate when the image demands it (e.g. straighten isn't needed at all), but deviate deliberately, not by reaching for the nearest slider.

Target values — how far to push

Numbers a novice doesn't have. These are the guard-rails:

• exposure: most real fixes live within ±1 EV. If you find yourself wanting more than ~±1.5 EV, the problem is the wrong starting frame, not an edit — nudge, re-look, repeat.
• tone highlights: −30 to −60 pulls a bright/blown sky back to detail. Beyond −80 the sky goes gray and dead.
• tone shadows: +20 to +50 opens shadows naturally. Beyond +70 you get the milky, flat, HDR-lifted-black look that screams amateur. Never lift shadows hard and drop contrast — they fight, and you end up with fog.
• whiteBalance: neutralize the cast first, then (optionally) push +10 to +20 warm for mood. Don't conflate the two moves. Correcting a cool shade shot might be temp +30; adding sunset warmth on top is a separate +15. Over-warming until skin goes orange is the classic "fix WB by eye" mistake — stop at "neutral," then add mood on purpose.
• contrast: +0.15 to +0.35 adds punch. +0.5 and up crushes shadow detail and clips highlights. Negative contrast only to tame a genuinely harsh image.
• vibrance: +0.3 to +0.5 is a strong-but-natural boost. It's hard to make vibrance look cheap — that's why it's the default color move.
• saturation: leave at 1. Above ~1.3 globally it looks cheap and the skin goes radioactive. Use only for a deliberate punchy/retro intent.
• sharpen: 0.2 to 0.4 for most images. Above 0.6 you get crunchy edges and bright/dark halos along contrast lines.

The big amateur mistakes (and how the agent avoids them)

• Over-saturation. Cranking saturation to "make it pop." Pop comes from contrast + vibrance, not from oversaturated color. Default to vibrance; touch saturation rarely.
• Crushed or raised blacks killing contrast. Lifting shadows past +70 to "see more" produces flat fog. Crushing with +0.5 contrast murders shadow texture. The midtones are where the image lives.
• Over-warming WB. Correcting toward warm by eye almost always overshoots into orange skin. Neutralize to a real neutral first.
• Over-sharpening halos. Sharpening early (before tone/contrast) or above 0.6.
• Stacking ops that fight. shadows+ vs contrast+; a look plus manual color that pulls the opposite way; saturation on top of vibrance. Pick the move that does the job and stop.
• "Doing more" on a finished image. The hardest discipline. If it matches the intent, the correct next move is to stop.

When to STOP

"Done" looks like: the intent is met, neutrals are neutral, the subject is correctly exposed, there's a true black and a clean white without clipping detail you care about, and nothing screams "edited." If you've made 3-5 deliberate moves and the last one produced a small improvement, you're done. The agent has an iteration cap (each iteration re-renders the full config) — converge. Each pass should change less than the last as you home in; when the config is right, set done.

Color discipline — correct, then grade

The discipline that separates a pro color edit from an amateur one: two distinct steps, never collapsed.

1. Neutralize first. Remove any accidental cast with whiteBalance so neutrals are honest and skin is believable. This is your reference — the thing you deviate from. Check both axes: amateurs fix temp (blue↔yellow) and leave a green/magenta tint sitting in the frame (indoor/fluorescent/LED light throws green → push tint toward magenta).
2. Add mood on purpose. Only on a neutral base, push a deliberate cast (temp warm/cool) or build a splitTone grade. Always know how far from neutral you've gone, so dialing back is one move.

• Skin is the unforgiving reference. All skin sits in a narrow warm hue band (~25–35°); melanin changes brightness/saturation, not hue. Viewers read skin as "wrong" instantly. The loud tells: orange/jaundice (over-warm), magenta/sunburn (tint), green/ sickly (uncorrected fluorescent). Check faces first; off skin = the whole edit is too far.
• Vibrance over saturation, always, on anything with people — vibrance protects skin and already-vivid colors. Oversaturation is the #1 amateur tell. saturation < 1 is the right tool for a deliberately muted/film/moody look; saturation > ~1.3 globally looks cheap.
• Harmony reads as intentional. Teal-orange works because skin is warm (~30°) and teal shadows (~200–210°) sit opposite it, separating subject from environment. Keep a clean warm/cool axis — warm highlights, cool shadows is the "expensive" default; tinting both zones the same way makes mud. A constrained 2–4 color palette reads premium; a rainbow reads amateur. The shadow tint reads far stronger than the highlight tint.

Intent → ops (the translation layer)

Interpret vague/emotional words into the right moves — don't take them literally when the real goal wants more.

User says	Do this	Not this
"tighten" / "crop in" / "too much dead space"	crop a smaller keep-rect around the subject	leave the frame and just darken edges
"make it square" / "for instagram"	crop to 1:1 (centered square)	stretch / squish
"straighten" / "it's crooked"	straighten to the true horizon / verticals (small angle)	crop the tilt away
"warm it up"	whiteBalance temp+ (stop before skin goes orange)	saturation
"make it pop"	a true black and clean white + contrast +0.2 + vibrance +0.3, maybe a little sharpen	crank saturation
"fix the lighting"	exposure, then tone	contrast / a creative look
"clean" / "crisp"	neutral WB, true blacks (not lifted), controlled vibrance, gentle contrast, light sharpen	mood / cast
"moody"	vibrance-led desaturation, strong S-curve, cooler WB, cool shadows; lift shadows only a little	brighten + saturate
"cinematic"	splitTone (shadowHue205 teal + highlightHue38 orange, shadowSat 30–45 > highlightSat), low saturation; or look tealOrange	crank saturation
"dramatic"	contrast +0.25–0.35, small dehaze, deepen shadows but hold highlight detail	lift everything
"nostalgic" / "vintage / film"	look vintageFade, or lift the black point + warm shadow tint + saturation <1 + soft contrast	random warm + grain
"airy" / "light" / "bright"	exposure+ (no clipping), LOW contrast, lift shadows toward gray, slightly warm WB, soft desaturated color	high contrast
"gritty"	dehaze/clarity up, high contrast, saturation down	just darken
"golden hour feel"	look goldenHour, or warm WB + tone shadows+	just saturation
"black and white"	look noir	saturation 0
"flat / dull"	contrast + vibrance	exposure up
"too dark"	exposure +, then tone shadows+	contrast down
"blown out sky"	tone highlights−	exposure down (darkens everything)

The looks — when each, and when NOT

• goldenHour — warm, glowing, sunset light. Not for mid-day, blue-hour, or any clean/cool intent; it'll fight the scene's own color.
• tealOrange — cinematic teal shadows / orange skin. Great on people and warm scenes. Not on red- or green-dominant frames (foliage, brick) — it clashes and muddies.
• noir — high-contrast black & white. Use when tonal drama is the point. Not when the color is the subject (a sunset, a red dress).
• vintageFade — lifted blacks, muted color, retro film. Not when you want crispness, clarity, or accurate color.
• crispClean — neutral, punchy, commercial. Not when you want mood or atmosphere; it strips it out.

Self-correction discipline

The agent re-looks at the rendered config after every pass — use it. The image is always re-rendered from the original, so correcting an overshoot is free: just set the slider to the right value. There's no penalty for lowering a slider and no inverse op to pile on.

• Overshot? Set the slider lower, full stop. If contrast 0.4 was too much, return contrast 0.25 — the re-render reflects exactly that, with nothing left over from the prior pass.
• Crushed blacks (lost shadow texture)? Raise tone shadows a little, or dial the contrast value back down.
• Halos / crunch? Lower sharpen.
• Clipped after exposure? Pull tone highlights more negative rather than darkening the whole image with exposure.
• Each pass should change less than the last as you converge. When the config matches the intent, set done.