[USER INPUT — REQUIRED AT TOP]

IMAGE: {แนบภาพบุคคลที่ต้องการ — optional แต่แนะนำเป็นอย่างยิ่ง}
SUBJECT: Optional

BACKGROUND_COLOR: {Solide white}
ASPECT_RATIO: Auto
LIGHTING_MOOD: Auto
STRING_DETAIL: Auto
EXPRESSION_INTENSITY: moderate inflatio

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STEP 0 — SUBJECT IDENTITY RESOLUTION
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Resolve the subject identity using priority logic:

CASE A — IMAGE + SUBJECT text both provided (maximum fidelity mode):
  → Use IMAGE as the primary visual reference and source of truth.
  → Use SUBJECT text to confirm, disambiguate, or supplement identity.
  → Extract from image: exact facial structure, bone geometry, 
     skin tone, skin texture, pore pattern, eye shape, lip shape, 
     jawline, hairline, hair volume, hair color, hair texture, 
     curl pattern, strand density, hairstyle silhouette.
  → Lock all extracted features as SUBJECT_IDENTITY.

CASE B — IMAGE only, no SUBJECT text:
  → Analyze uploaded image.
  → Extract full facial and hair profile as described in Case A.
  → Proceed automatically.
  → Lock extracted profile as SUBJECT_IDENTITY.

CASE C — SUBJECT text only, no IMAGE:
  → Reconstruct subject appearance from SUBJECT description.
  → If a known public figure: use well-documented facial reference 
     from training knowledge. Reproduce accurately.
  → If a descriptive subject (e.g., "elderly Japanese man"): 
     generate a realistic, specific, non-generic face.
  → Lock as SUBJECT_IDENTITY.

CASE D — Neither IMAGE nor SUBJECT provided:
  → Halt. Return: 
     "Please provide an uploaded image (IMAGE) or a subject 
     description (SUBJECT) — at least one is required."

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STEP 1 — IDENTITY PRESERVATION LOCK
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Before any transformation is applied, lock the following 
attributes as IMMUTABLE — they must survive the balloon 
effect completely unchanged:

FACE & SKIN:
  □ Facial bone structure and proportions
  □ Eye shape, size, color, lid crease
  □ Nose shape and width
  □ Lip shape and natural color
  □ Skin tone and undertone (warm / cool / neutral)
  □ Visible pores, micro-texture, freckles, moles — preserved exactly
  □ Ethnicity-accurate skin detail

HAIR (CRITICAL — ZERO MODIFICATION ALLOWED):
  □ Hairstyle silhouette — identical
  □ Hairline shape and position — identical
  □ Hair color and highlights — identical
  □ Hair texture: straight / wavy / curly / coily — identical
  □ Strand density and volume — identical
  □ Individual strand behavior and movement — preserved
  □ Hair does NOT receive balloon material treatment
  □ Hair does NOT flatten, shrink, smooth, or disappear
  □ Hair remains fully physical, rendered with realistic 
     subsurface and highlight response

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STEP 2 — BALLOON TRANSFORMATION RULES
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Apply balloon inflation effect ONLY to these regions:

AFFECTED ZONES:
  → Skull shape: inflated, rounded, slightly enlarged
  → Cheeks: fully puffed with realistic inward skin tension
  → Forehead: smooth inflation dome, skin stretched naturally
  → Lips: slightly pursed as if holding air, subtle outward push
  → Chin and jaw: softened by inflation pressure

SKIN PHYSICS (must feel anatomically real):
  → Natural skin tension — not rubber, not latex, not plastic
  → Realistic stretch marks and micro-compression at inflation seams
  → Subsurface scattering preserved — skin glows from within 
     like real pressurized tissue, not a synthetic membrane
  → Pores visible and intact across inflated surface
  → No CGI sheen, no balloon-toy gloss, no latex specularity

NECK — BALLOON TIE ZONE:
  → Neck morphs into a tied balloon tip
  → Material: stretched human skin with compression folds
  → Knot detail: realistic skin-colored tie with tension creases
  → Below the knot: a thin string, {STRING_DETAIL} style
  → Transition from face to tie must feel physically plausible

EXPRESSION:
  → Intensity follows {EXPRESSION_INTENSITY}
  → Subtle: barely puffed, slight cheek pressure
  → Moderate: clearly inflated, pursed lips, visible tension
  → Full: maximum inflation, taut skin dome, strong lip purse

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STEP 3 — CAMERA & TECHNICAL SPECS
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Camera system:
  → Body: Sony A7R V
  → Lens: Sony FE 85mm f/1.4 GM II
  → Aperture: f/1.4–f/2.0 (shallow depth of field)
  → Focus point: eyes and upper cheekbones
  → Background falls to soft bokeh

Framing:
  → Medium close-up floating head, centered
  → Head fully in frame with neck-tie and string visible
  → No shoulders or body unless SUBJECT requires context

Lighting — follows {LIGHTING_MOOD}:
  → Soft diffused (default): large softbox from 45° left, 
     subtle fill from right, natural catchlights in eyes
  → Dramatic: strong key light, deep shadow on one side
  → Rim-heavy: backlit rim separation emphasizing balloon 
     form against background
  → High-key: even bright studio wash, minimal shadow

Lighting must also:
  → Respond correctly to hair: realistic strand highlights, 
     natural sheen, depth in darker hair areas
  → Respond to skin inflation: subtle highlight at the 
     peak of each inflated surface curve
  → Subtle rim light separating head from background

Technical quality:
  → Ultra-high resolution, 8K detail
  → Realistic subsurface scattering
  → Cinematic film grain (subtle)
  → Zero plastic sheen, zero CGI flatness

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STEP 4 — BACKGROUND & FINAL COMPOSITION
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Background:
  → User value if BACKGROUND_COLOR provided.
  → Default: smooth navy blue gradient, minimal studio.
  → Gradient falls dark toward edges, slightly lighter behind head.
  → No props, no textures, no distracting elements.

Aspect ratio: {ASPECT_RATIO}

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NEGATIVE CONSTRAINTS (ABSOLUTE HARD RULES)
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IDENTITY:
  ✗ No change to facial bone structure or proportions
  ✗ No skin tone shift
  ✗ No eye color or shape alteration

HAIR (ZERO TOLERANCE):
  ✗ No bald transformation
  ✗ No hair removal or thinning
  ✗ No hair smoothing or flattening
  ✗ No hair converted to balloon skin material
  ✗ No hairstyle change of any kind

MATERIAL:
  ✗ No latex material appearance
  ✗ No rubber texture
  ✗ No plastic sheen or toy-like specularity
  ✗ No cartoon or illustrated look
  ✗ No CGI render quality — must feel photographic

PHYSICS:
  ✗ No anatomically impossible inflation geometry
  ✗ No detached floating elements
  ✗ No surreal color shifts on skin

COMPOSITION:
  ✗ No extra hands, props, or environmental objects 
    unless explicitly requested
  ✗ No text overlays
  ✗ No double exposure or collage effects