1. A video surveillance system comprising: a plurality of cameras that capture images; a display apparatus that displays the images captured by the cameras; an information generating apparatus that generates information for searching the images captured by the cameras; a search apparatus that searches the images captured by the cameras; and an image storage apparatus that stores the images captured by the cameras, wherein the information generating apparatus acquires the images captured by the cameras, generates retrieval data from the acquired images, and when an event is detected, transmits the generated retrieval data to the search apparatus, wherein image features are used as the retrieval data, wherein the search apparatus stores the retrieval data received from the information generating apparatus in a storage device, searches the retrieval data of the acquired images in the image storage apparatus, and transmits, to the display apparatus, the stored retrieval data, a registration event notice indicating that the retrieval data has been registered together with an identifier of the retrieval data registered, and results of searching the stored retrieval data, wherein the display apparatus receives the retrieval data and the identifier of the retrieval data registered, determines whether an image related to the retrieval data is required based on the retrieval data received from the search apparatus, and transmits an image transmission request to the image storage apparatus to transmit the image related to the retrieval data when determining that the image related to the retrieval data is required, wherein the image storage apparatus transmits the requested image data to the display apparatus, which is a request source, in response to the image transmission request from the display apparatus, and wherein the display apparatus displays the image data acquired from the image storage apparatus.