Method of displaying a thumbnail image, server computer, and client computer

A server computer causing a thumbnail image of an original image of a data file stored in a storage unit of the server computer to be displayed on a display unit of a client computer in accordance with an instruction therefrom, the client computer being connected to the server computer via a network, the server computer comprising:

• a thumbnail image storage unit to store in the storage unit a first compressed code relating to an image for displaying the thumbnail image of the data file, the first compressed code being generated by dividing the image into a plurality of tiles and performing discrete wavelet transform and hierarchical encoding on pixel values of the image tile by tile;
• a thumbnail image setting acquisition unit to acquire from the client computer a resolution of the thumbnail image, the resolution being set in accordance with a format type of the data file;
• a thumbnail image extraction unit to extract a second compressed code according to the resolution acquired by the thumbnail image setting acquisition unit from the first compressed code stored in the storage unit;
• and
• a thumbnail image transmission unit to transmit the second compressed code extracted by the thumbnail image extraction unit to the client computer.

A computer-readable recording medium storing a program for causing a server computer to execute a method of displaying a thumbnail image of an original image of a data file stored in a storage unit of the server computer on a display unit of a client computer in accordance with an instruction therefrom, the client computer being connected to the server computer via a network, the method comprising:

• (a) acquiring from the client computer a resolution of the thumbnail image, the resolution being set in accordance with a format type of the data file;
• (b) extracting a first compressed code according to the resolution from a second compressed code stored in the storage unit, the second compressed code relating to an image for displaying the thumbnail image of the data file and being generated by dividing the image into a plurality of tiles and performing discrete wavelet transform and hierarchical encoding on pixel values of the image tile by tile;
• and
• (c) transmitting the first compressed code to the client computer.