This is different from photographing a document displayed on a monitor. Lizard is an open-source research project that turns file data into successive grey patterns, then reconstructs the file using a phone camera. Its author says each image’s border also carries information describing the format.
Collecting and checking the pieces
The published sending and receiving code makes part of that journey concrete. The sender divides a file into chunks, tries compressing each one, and sends the compressed version only when it is smaller. The receiver rebuilds chunks from collected blocks and decompresses them when needed. Chunks that fail a content check are collected again; completion requires every chunk to pass. We read this transfer-handling code, without testing camera recognition performance.
V’s view
V’s view. The intriguing shift is that a screen becomes a channel for carrying data as well as a surface for displaying it. Between seeing a pattern clearly and receiving a whole file, however, sits the work of collecting and checking its pieces.
Limits
Limits: the author describes a research project whose format still changes. Results depend on screen and camera conditions, and published performance figures are reports from the author’s limited equipment. We did not verify speed or transfer success rates.