Chameleon: A Surface-Anchored Smartphone AR Prototype with Visually Blended Mobile Display

Augmented reality (AR) is often realized through head-mounted displays, offering immersive but egocentric experiences. While smartphone-based AR is more accessible, it remains limited to handheld, single-user interaction. We introduce Chameleon, a prototype AR system that transforms smartphones into surface-anchored displays for co-located use. When placed flat, the phone creates a transparency illusion and anchors digital content visible to multiple users. Chameleon supports natural repositioning on the surface without external hardware by combining two techniques: (1) Background Acquisition uses opportunistic sensing and language model-assisted pattern generation to blend with surrounding surfaces, and (2) Real-Time Position Tracking augments inertial sensing to maintain spatial stability. This work shows how lightweight sensing can support casual, collaborative AR experiences using existing devices.