Multi-Projector System — Project Wiki¶

Overview
Our goal is to build a two‑projector system that displays seamless still images on a flat screen, where the projected areas overlap and must be blended. Implementation is in Python (OpenCV). Prior to implementation, we document the problem and a viable solution approach. #Scope #Team¶

Problem background (why blending matters)
Overlapped regions become over‑illuminated; alpha‑blending with proper masks evens illumination across seams. (See slides: “What is alpha‑blending?”) Alpha‑blending¶

Scope & assumptions

• Start from a planar screen with two projectors; optical axes perpendicular to the screen.
• Work with still images first (not video).
• Expected overlapped area is approximately rectangular; target a linear drop of mask intensity from 1→0 across the overlap.
• Use Python + OpenCV; iterate from simple to refined.
  (From project brief and simplified requirements.)

Objectives

• Describe the problem and identify a potential solution before coding.
• Apply geometric reasoning (lines/planes in 3D; ray‑plane/ray‑cylinder intersections) as needed.
• Prototype masking that yields smooth, artifact‑free blending.
  (From “Objective”, “Skills required”, and problem formulation.)

Key concepts & references

• Alpha‑blending — concept and examples.
• Forward (screen→projector) and inverse (projector→screen) ray tracing for overlap detection and mask generation.
• “Smooth” masks prevent scratches along mask boundaries.

Team & roles

Roles	Members
Advisor	Great Gilbert Soco
PL, Project Leader	Koki
PM, Project Manager	Noah
Redmine – supporter of PM	Nonoka
Developers	Deng, Gilbert
Doxygen Leader	Hachiko (Haziq)
Doxygen, commenters	Jordan, Hazel, Sota
Wiki Leader	Gilbert
Wiki Developers	Zoya, Phillip Anderson
Jira Research Team	Zack, Phillip Anderson

Alpha‑blending (notes)
Overlapped areas without masks are brighter; masks weight each projector so the sum equals uniform brightness. Smooth masks eliminate boundary scratches; see examples in the slides.¶

Project links

• Requirements & assumptions: this page, sections #Scope and #Objectives.
• Design notes & diagrams: (create) Design-Notes
• Experiments log & photos: (create) Experiments-Log
• Code repo / file list: (link later)

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