Visual Prompting: Visual Grammar v0 + Serialization

Visual Prompting: Visual Grammar v0 + Serialization

Product North Star

Visual prompting is a composition language: layout (arrangement + whitespace) communicates intent, and explicit marks (circles/boxes/arrows/labels) disambiguate what to edit.

This doc proposes a minimal "visual grammar v0" and the first thin-slice implementation: emit a machine-readable visual_prompt.json from the desktop canvas, plus one new annotation primitive (red circle labels).

Visual Grammar v0 (Spec)

1) Layout Rules (implicit semantics)

• Side-by-side (2-up): "blend / combine A + B"
  • In Brood today: multi-canvas + Combine quick action (/blend) is the canonical behavior.
• Vertical stack: "sequential states" (A -> B -> C)
  • Interpretation: treat as a timeline; compare deltas; generate next state.
• Grid (2x2 / 3x3): "variants / compare"
  • Interpretation: same prompt family; prefer describing differences over fusing.
• Whitespace separation: grouping boundary
  • Interpretation: distinct groups are separate tasks unless a mark/label explicitly links them.

2) Annotation Primitives (explicit semantics)

• Box (existing): bounded edit region
  • Default semantic: "edit only inside" (green box).
• Circle (new): attention / "fix this"
  • Default semantic: red circle = fix this area.
• Arrow (v0 concept; not implemented yet): relationship / transfer / movement
  • Default semantic: "move/replace from A to B" (tail = source, head = target).
• Text label (v0 concept; partially implemented via circle label): literal instruction string
  • Always treated as verbatim instruction text.

3) Color Semantics (v0)

• Red circle: "fix this"
• Green box: "edit only inside"
• Yellow lasso: subject mask candidate / selection

4) Examples (mental model)

• Two product photos side-by-side + label "blend lighting + keep logo sharp" -> combine/blend behavior.
• Screenshot stack (3-up) + red circles on each -> "fix these issues in sequence".
• Green box around background + label "make background pure white" -> edit within region only.

Visual Prompt Serialization v0 (JSON)

File location

• Written to the current run directory as: runDir/visual_prompt.json
• Produced by the desktop app (desktop/src/canvas_app.js).

Shape (current)

Top-level fields:

• schema, schema_version
• visual_grammar_version
• updated_at
• run_dir
• canvas: mode, DPR, canvas size, active image id, tool, view transforms, and multi-layout rects
• images: image ids + paths + dimensions
• marks: normalized mark list (per-mark metadata + image-space geometry)

Mark shape:

• id
• type: lasso_polygon | box | circle
• color: CSS RGBA string
• label: optional string (literal instruction/label)
• target_image_id
• image_space: geometry in image pixel coordinates
• created_at

Notes:

• multi_rects_px are in canvas device pixels (DPR-scaled), and multi_view.offset_* are the pan offsets applied on top.
• In v0, the annotate box mark is only serialized while it exists in the UI (it is cleared after sending/canceling). Persisted box history is a next step.

Smallest Shippable Implementation Plan

1. Spec-first: keep this doc updated as the "contract" for how layout + marks map to meaning.
2. Always-on serialization: write visual_prompt.json on key state changes (run init, image import, tool interactions, marks created/edited/deleted, pan/zoom).
3. One new primitive: add red circle labels:
   • Create via Shift + drag (Annotate tool)
   • Render as overlay + label
   • Edit label via a small panel
   • Delete via panel or Delete/Backspace
4. Next thin slice (recommended):
   • Add a Fix action that targets the last/selected red circle:
     • Convert circle -> normalized region coords
     • Compose edit prompt from circle label + region
     • Call engine edit path end-to-end