Seeing the out-of-sight has turned a new corner. Now, digital cameras can take an image of an object hidden around a wall, which could help autonomous cars detect hazards in blind spots.
In principle, any vertical edge can act as an accidental camera, by projecting subtle patterns of light onto the ground. These patterns reveal a semblance of what is happening on the other side of the edge and, though too faint to be noticed by the human eye, can be enhanced and interpreted by imaging algorithms.
Until now, however, these algorithms have required videos not images and …