Image transmission system, method of the same, and recording medium

• US 20020037091A1
• Filed: 09/19/2001
• Published: 03/28/2002
• Est. Priority Date: 09/25/2000
• Status: Active Grant

• Current Assignee: NEC Personal Computers, Ltd. (Lenovo Group Ltd.)
• Original Assignee: NEC Corporation
• Inventors: Terasaki, Hiroshi
• Granted Patent: US 6,947,572 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: G06T 2201/0064 for copy protection or copy management, e.g. CGMS, copy only once, one-time copy
• CPC Class Codes: H04L 63/0435 wherein the sending and receiving network entities apply symmetric encryption, i.e. same key used for encryption and decryption cryptographic mechanisms or cryptographic arrangements for symmetric key encryption H04L9/06
• CPC Class Codes: H04L 63/062 for key distribution, e.g. centrally by trusted party cryptographic mechanisms or cryptographic arrangements for key distribution involving a central third party H04L9/0819
• CPC Class Codes: H04L 63/126 the source of the received data
• CPC Class Codes: H04N 1/32128 attached to the image data, e.g. file header, transmitted message header, information on the same page or in the same computer file as the image for information embedded in the image H04N1/32144
• CPC Class Codes: H04N 1/32144 embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
• CPC Class Codes: H04N 1/32776 using an interactive, user-operated device, e.g. a computer terminal, mobile telephone H04N1/32782, H04N1/32784 take precedence
• CPC Class Codes: H04N 2201/3233 of authentication information, e.g. digital signature, watermark
• CPC Class Codes: H04N 2201/325 Modified version of the image, e.g. part of the image, image reduced in size or resolution, thumbnail or screennail

Abstract

An image transmission system includes: a client; a server; and a network connecting the client and the server. The client includes: an image request section that requests transmission of image data; an output instruction section that issues an output instruction for an image data file of a general purpose format; and an output section that outputs the image data file of the general purpose format specified as an output file. The server includes: a watermark insertion section that forms high-resolution data as an image data file to be transmitted and low-resolution data as a general purpose format file of image data to which an electronic watermark is given to specify the high-resolution data as watermark information whose resolution is reduced relative to the high-resolution data; and a distribution section that transmits the high-resolution data, the low-resolution data and a data selection program. The data selection program allows the client to detect existence of the low-resolution data to which the output instruction is made, and it specifies the high-resolution data from watermark information to designate the high-resolution data as the output file when the electronic watermark is detected and designates the low-resolution data as the output file when the electronic watermark is not detected.

Claims

1. An image transmission system, comprising:

a client comprising;

an image request section that requests transmission of image data;

an output instruction section that instructs output of an image data file of a general purpose format; and

an output section that outputs the image data file of the general purpose format designated as an output file;

a server comprising;

high-resolution data as the image data file to be transmitted;

a watermark insertion section that forms low-resolution data as the general purpose format file of the image data, to which an electronic watermark is given to specify the high-resolution data as watermark information whose resolution is reduced relative to said high-resolution data; and

a distribution section that transmits the high-resolution data, the low-resolution data, and a data selection program that allows the client to execute a watermark detection processing, wherein said data selection program allows the client to detect existence of the electronic watermark of the low-resolution data whose output is instructed, to specify the high-resolution data from the watermark information and to designate the high-resolution data as the output file when the watermark information is detected, and the low-resolution data is designated as the output data when the watermark information is not detected; and

a network that connects the client and the server.

2. The image transmission system according to claim 1, wherein said server further secretly holds a secret key that encodes said high-resolution data,

said client further comprises a decoding section that decodes the encoded high-resolution data,

said distribution section distributes said low-resolution data, the encoded high-resolution data which is made by encoding said high-resolution data, said data selection program and said secret key to the client via the network, when the client requests transmission of the image data file, and

said data selection program allows said decoding section to decode said encoded high-resolution data by using said secret key, when the electronic watermark is detected in the client.

3. The image transmission system according to claim 2, wherein said server further includes a verification section that distributes said secret key when the client who requests purchasing of data is verified to be a right decoder of encoded data,

said distribution section distributes said low-resolution data, the encoded high-resolution data and said data selection program to the client via the network, when the client requests transmission of the image data file, and

said data selection program allows said client to be subject to an instrument verification by said verification section, when the electronic watermark is detected in the client, and allows the decoding section to decode said encoded high-resolution data by using said secret key, when the client is verified to be the right decoder of the encoded data to receive the data.

4. The image transmission system according to claim 2, wherein said watermark insertion section further inserts the electronic watermark having the secret key as a watermark information, and

said data selection program allows the client to obtain said secret key as one of extracted watermark information and allows the decoding section to decode the encoded high-resolution data by using said secret key, when the electronic watermark is detected in the client.

5. An image transmission method, comprising the steps of:

forming low-resolution data as a general purpose format file of image data by a server, to which an electronic watermark is given to specify high-resolution data as watermark information whose resolution is reduced relative to high-resolution data being an image data file to be transmitted;

requesting transmission of the image data file by a client connected with the server via a network; and

transmitting a program in which the server allows the client to detect the high-resolution data, the low-resolution data, and existence of the electronic watermark of the low-resolution data whose output is instructed, and the program that allows the client to execute a watermark detection processing of specifying the high-resolution data from watermark information to designate the high-resolution data as an output file when the electronic watermark is detected and designating the low-resolution data as the output file when the electronic watermark is not detected.

6. A recording medium, wherein a program is recorded such that a server is enabled to read the program that allows said server connected with a client who requests transmission of an image data file via a network to execute a processing of forming low-resolution data as a general purpose format file of image data to which an electronic watermark is given to specify high-resolution data as watermark information whose resolution is reduced relative to high-resolution data being an image data file to be transmitted, and to execute a processing of transmitting a program in which the server allows the client to detect the high-resolution data, the low-resolution data, and existence of the electronic watermark of the low-resolution data whose output is instructed, and the program that allows the client to execute a watermark detection processing of specifying the high-resolution data from watermark information to designate the high-resolution data as an output file when the electronic watermark is detected and designating the low-resolution data as the output file when the electronic watermark is not detected.