Image data alteration preventing apparatus and alteration preventing method

• US 6,643,451 B1
• Filed: 03/24/1999
• Issued: 11/04/2003
• Est. Priority Date: 03/25/1998
• Status: Expired due to Fees

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Suzuki, Shiro, Tokura, Masanori
• Primary Examiner(s): Tran, Thai
• Assistant Examiner(s): CHIEU, PO LIN
• Application Number:
  US09/274,762
• Time in Patent Office: 1,686 Days
• Field of Search: 386/1, 386/40, 386/45, 386/94, 386/124-126, 360/60, 380/201, 380/203
• US Class Current: 386/258
• CPC Class Codes: H04N 21/440254 by altering signal-to-noise parameters, e.g. requantization
• CPC Class Codes: H04N 21/4753 for user identification, e.g. by entering a PIN or password cryptographic authentication protocols H04L9/32; networks authentication protocols H04L63/08
• CPC Class Codes: H04N 21/8352 involving content or source identification data, e.g. Unique Material Identifier [UMID]
• CPC Class Codes: H04N 5/76 Television signal recording
• CPC Class Codes: H04N 5/915 for field- or frame-skip recording or reproducing
• CPC Class Codes: H04N 5/9201 involving the multiplexing of an additional signal and the video signal
• CPC Class Codes: H04N 7/16 Analogue secrecy systems; Analogue subscription systems

Abstract

An image data alteration preventing apparatus according to the present invention comprises recording means for producing first alteration detecting data on the basis of image data, to record the produced first alteration detecting data, together with the image data, on a recording medium, and examining means for producing second alteration detecting data on the basis of the image data read out of the recording medium, and collating the produced second alteration detecting data and the first alteration detecting data read out of the recording medium, to judge whether or not the image data read out of the recording medium is altered.

Claims

1. An image data alteration preventing apparatus comprising:

recording means for producing first alteration detecting data on the basis of image data, to record the produced first alteration detecting data, together with the image data, on a recording medium; and

examining means for producing second alteration detecting data on the basis of the image data read out of the recording medium, and collating the produced second alteration detecting data and the first alteration detecting data read out of the recording medium, to judge whether or not the image data read out of the recording medium is altered.

2. An image data alteration preventing apparatus comprising:

recording means for producing first alteration detecting data on the basis of image data, to record the produced first alteration detecting data, together with the image data, on a recording medium; and

examining means for producing second alteration detecting data on the basis of the image data read out of the recording medium, and collating the produced second alteration detecting data and the first alteration detecting data read out of the recording medium, to judge whether or not the image data read out of the recording medium is altered,

wherein the recording means comprises

means for blocking in field units the image data such that the width thereof is previously determined n bytes long,

means for subjecting image data for each block to a predetermined first operation in the longitudinal direction, to obtain first alteration detecting data which is n bytes long, and

means for recording the first alteration detecting data, together with the image data, on the recording medium, and the examining means comprises

means for blocking in field units the image data read out of the recording medium such that the width thereof is previously determined n bytes long,

means for subjecting image data for each block to said first operation in the longitudinal direction, to obtain second alteration detecting data which is n bytes long, and

means for collating the obtained second alteration detecting data and the first alteration detecting data read out of the recording medium, to judge whether or not the image data read out of the recording medium is altered.

3. An image data alteration preventing apparatus comprising:

recording means for producing first alteration detecting data on the basis of image data, to record the produced first alteration detecting data, together with the image data, on a recording medium; and

examining means for producing second alteration detecting data on the basis of the image data read out of the recording medium, and collating the produced second alteration detecting data and the first alteration detecting data read out of the recording medium, to judge whether or not the image data read out of the recording medium is altered,

wherein the recording means comprises

means for blocking in field units the image data such that the width thereof is previously determined n bytes long,

means for subjecting image data for each block to a predetermined first operation in the longitudinal direction, to obtain the result of the operation which is n bytes long,

means for subjecting the obtained result of the operation to a predetermined second operation, to obtain first alteration detecting data which is n bytes long, and

means for recording the first alteration detecting data, together with the image data, on the recording medium, and the examining means comprises

means for blocking in field units the image data read out of the recording medium such that the width thereof is previously determined n bytes long,

means for subjecting image data for each block to said first operation in the longitudinal direction, to obtain the result of the operation which is n bytes long,

means for subjecting the obtained result of the operation to said second operation, to obtain second alteration detecting data which is n bytes long, and

means for collating the obtained second alteration detecting data and the first alteration detecting data read out of the recording medium, to judge whether or not the image data read out of the recording medium is altered.

4. An image data alteration preventing method comprising:

the recording step of producing first alteration detecting data on the basis of image data, to record the produced first alteration detecting data, together with the image data, on a recording medium; and

the examining step of producing second alteration detecting data on the basis of the image data read out of the recording medium, and collating the produced second alteration detecting data and the first alteration detecting data read out of the recording medium, to judge whether or not the image data read out of the recording medium is altered.

5. An image data alteration preventing method comprising:

the recording step of producing first alteration detecting data on the basis of image data, to record the produced first alteration detecting data, together with the image data, on a recording medium; and

the examining step of producing second alteration detecting data on the basis of the image data read out of the recording medium, and collating the produced second alteration detecting data and the first alteration detecting data read out of the recording medium, to judge whether or not the image data read out of the recording medium is altered,

wherein the recording step comprises the steps of

blocking in field units the image data such that the width thereof is previously determined n bytes long,

subjecting image data for each block to a predetermined first operation in the longitudinal direction, to obtain the first alteration detecting data which is n bytes long, and

recording the first alteration detecting data, together with the image data, on the recording medium, and

the examining step comprises the steps of

blocking in field units the image data read out of the recording medium such that the width thereof is previously determined n bytes long,

subjecting image data for each block to said first operation in the longitudinal direction, to obtain the second alteration detecting data which is n bytes long, and

collating the obtained second alteration detecting data and the first alteration detecting data read out of the recording medium, to judge whether or not the image data read out of the recording medium is altered.

6. An image data alteration preventing method comprising:

the recording step of producing first alteration detecting data on the basis of image data, to record the produced first alteration detecting data, together with the image data, on a recording medium; and

the examining step of producing second alteration detecting data on the basis of the image data read out of the recording medium, and collating the produced second alteration detecting data and the first alteration detecting data read out of the recording medium, to judge whether or not the image data read out of the recording medium is altered,

wherein the recording step comprises the steps of

blocking in field units the image data such that the width thereof is previously determined n bytes long,

subjecting image data for each block to a predetermined first operation in the longitudinal direction, to obtain the result of the operation which is n bytes long,

subjecting the obtained result of the operation to a predetermined second operation, to obtain first alteration detecting data which is n bytes long, and

recording the first alteration detecting data, together with the image data, on the recording medium, and

the examining step comprises the steps of

blocking in field units the image data read out of the recording medium such that the width thereof is previously determined n bytes long,

subjecting image data for each block to said first operation in the longitudinal direction, to obtain the result of the operation which is n bytes long, and

subjecting the obtained result of the operation to said second operation, to obtain second alteration detecting data which is n bytes long, and

collating the obtained second alteration detecting data and the first alteration detecting data read out of the recording medium, to judge whether or not the image data read out of the recording medium is altered.