Lantern: one walk with a phone becomes an offline indoor map, built by Gemma 4

Description and use

Lantern turns a single phone walk into an offline indoor map with photo‑based step directions, usable without internet or GPS.

Problem

Visitors in large buildings without indoor maps cannot find facilities when network is blocked.

Outcome

Lantern creates a usable offline indoor map in under two minutes from a single phone walk, enabling navigation in crowded venues without internet or GPS.

Workflow

• 1. Walk through the building once, filming and narrating place names.
• 2. Gemma 4 processes the video, extracting frames and aligning narration to create a map JSON.
• 3. A reviewer checks and edits the map on a review page, then prints QR signs.
• 4. Visitors scan a QR sign and follow step‑by‑step photo directions, with audio read‑out, in offline mode.

Evidence

Lantern turns one walk into a map that works offline

Source

Someone walks through the building once, filming on their phone and saying what they see

Source

Gemma 4, running on a laptop, turns that video into a map

Source

Visitors scan a sign and walk. One instruction at a time, each with a photo of the next landmark

Source

Lantern makes a venue navigable in an afternoon, for visitors who are elderly, new to smartphones, or don't read English well

Source