An imaging system capture images of products on shelves in a minimally invasive way. The images can be processed to assess restocking needs and other information. The imaging system includes multiple shelf-mountable imaging devices that can be positioned throughout one or more retail locations. Certain types of imaging devices may be self-contained units having replaceable or rechargeable internal power sources and/or wireless communication interfaces. Certain types of imaging device are configured to take images only when the field of view is not blocked by traffic (e.g., consumers, employees, etc.). Certain types of imaging devices are low-profile and/or are camouflageable to enhance the user experience.