SIGMA-Gen: Multi-Subject Image Composition

Insert identity-preserving subjects into any scene.

Adobe UMass Amherst
Paper: SIGMA-GEN: Structure and Identity Guided Multi-subject Assembly for Image Generation (arXiv:2510.06469)
Oindrila Saha, Vojtech Krs, Radomir Mech, Subhransu Maji, Kevin Blackburn-Matzen, Matheus Gadelha

Quick Start

  1. Leave the canvas blank to generate from scratch or upload a background image to edit it.
  2. Upload reference images for each subject (backgrounds are removed automatically)
  3. Select the Rectangle tool and a color from the canvas toolbar
  4. Draw regions on the canvas where each subject should appear
  5. Write a prompt describing the full final scene incorporating all subjects.
  6. Generate!

💡 Tip: Use the "Load Example" button in Settings to try pre-configured examples.

Drawing Tools

  • Rectangle: Click and drag to draw filled boxes
  • Eraser: Remove parts of your drawing

Modes (auto-detected)

  • Edit mode: When you upload a background image, subjects are inserted into that image.
  • Generate mode: A new image is generated with subjects at drawn locations.

Color to Subject Mapping
S1 | S2 | S3 | S4 | S5 | S6 | S7 | S8

Automatic Features

  • Background removal: Subject images have backgrounds removed automatically on upload
  • Mode detection: Edit vs Generate mode is detected based on whether a background is present
💡 Tip: Add subjects and draw masks in order of distance to the camera — from furthest to nearest.

Subject Reference Images

Upload reference images for subjects. Use +/- buttons to add or remove slots.
S1

Upload an image

Settings
10 50
1 10
Select Example

Drawing Canvas

Upload a background to edit, or draw directly to generate. Use Brush or Rectangle tools.
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Result
SIGMA-Gen Multi-Subject Composition | Powered by FLUX.1-Kontext
arXiv:2510.06469