A gate apparatus includes a memory storing one or more instructions; and a processor configured to execute the one or more instructions to: obtain an image including a plurality of persons captured by one or more cameras, each of the plurality of persons present at a first area in advance of a barrier, process the image to determine whether each of the plurality of persons at the first area is authorized to proceed through the barrier and control the barrier, based on a status that the plurality of persons are identified as being authorized or unauthorized.