A system that analyzes camera images to track a person in an autonomous store, and to determine when a tracked person takes or moves items in the store. The system may associate a field of influence volume around a person's location; intersection of this volume with an item storage area, such as a shelf, may trigger the system to look for changes in the items on the shelf. Items that are taken from, placed on, or moved on a shelf may be determined by a neural network that processes before and after images of the shelf. Person tracking may be performed by analyzing images from fisheye ceiling cameras projected onto a plane horizontal to the floor. Projected ceiling camera images may be analyzed using a neural network trained to recognize shopper locations. The autonomous store may include modular ceiling and shelving fixtures that contain cameras, lights, processors, and networking.