By using hierarchical encoding for image data compression, it is possible to perform effective and obliging remote edition work by taking advantage of the characteristic of the hierarchical encoding. A main edition device (Fig. 2) transmits hierarchically encoded data in accordance with the network use band and capability of the remote edition device among the hierarchically encoded data forming an image, to the remote edition device. At the remote edition device, an editor performs edition work by using this. The edition information created as a result of the edition work is transmitted from the remote edition device to the main edition device. The main edition device uses this and transmits differential hierarchically encoded data to the remote edition device. The remote edition device creates edition image data by using the hierarchically encoded data already received and the differential hierarchically encoded data transmitted from the main edition device. The hierarchically encoded data can perform fine hierarchization for the elements defining the image quality such as resolution and the image quality by performing hierarchical encoding.