To facilitate retrieval of moving image data by displaying the contents of moving image data on a network as a still picture at a client device.
A client device 301 outputs the request of preparation from moving image data to still picture data to a moving image chart preparing device 303. The moving image charge preparing device 303 accepts the chart image preparing request from the client device 301, extracts the frame of moving image data from the moving image data transferred from a server device 305 according to predetermined extraction rules, and prepares encoded still picture data concerning the extracted frame. The prepared still picture data are transferred to the client device 301. When using a motion picture expert group(MPEG) for the encoding system of moving image data and using a joint photographic expert group(JPEG) for the encoding system of still picture data to be outputted, for example, the frame for I pictures in the data of MPEG can be turned into still picture data.
KOHIYAMA TOMOHISA
KUWABARA YASUYUKI
