POSITION INFORMATION ADDING APPARATUS, POSITION INFORMATION ADDING METHOD, AND COMPUTER PROGRAM FOR ADDING POSITION INFORMATION AND POSITION DETECTION APPARATUS

• US 20140016817A1
• Filed: 09/20/2013
• Published: 01/16/2014
• Est. Priority Date: 03/22/2011
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: NAKAGATA, Shohei, KURAKI, Kensuke, TAKAHASHI, Jun, ANAN, Taizo
• Granted Patent: US 9,582,842 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: G06T 1/005 Robust watermarking, e.g. average attack or collusion attack resistant
• CPC Class Codes: G06T 1/0085 Time domain based watermarking, e.g. watermarks spread over several images
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06T 2201/0065 Extraction of an embedded watermark; Reliable detection
• CPC Class Codes: G06T 2201/0601 whereby calibration information is embedded in the watermark, e.g. a grid, a scale, a list of transformations
• CPC Class Codes: G06V 20/40 in video content extracting overlay text G06V20/62; video retrieval G06F16/70; processing of video elementary streams in video servers H04N21/234; processing of video elementary streams in video clients H04N21/44
• CPC Class Codes: H04N 19/467 characterised by the embedded information being invisible, e.g. watermarking
• CPC Class Codes: H04N 21/234345 the reformatting operation being performed only on part of the stream, e.g. a region of the image or a time segment
• CPC Class Codes: H04N 21/8358 involving watermark protecting executable software by watermarking G06F21/16; image watermarking in general G06T1/0021; watermarks inserted in still images for transmission purposes H04N1/32144; inserting watermarks during video coding H04N19/467

Abstract

A position information adding apparatus includes: a reference position setting unit which sets a plurality of reference positions for each of a plurality of pictures contained in digitalized video data; a region setting unit which sets a first position information adding region at a first position defined based on at least any of the plurality of reference positions and a second position information adding region at a second position different from the first position, for each of the plurality of pictures; and a position information embedding unit which embeds a first moving pattern which moves on the pictures in a first temporal period into the first position information adding region and a second moving pattern which moves on the pictures in a second temporal period into the second position information adding region.

Claims

1. A position information adding apparatus comprising:

a reference position setting unit which sets a plurality of reference positions for each of a plurality of pictures contained in digitalized video data;

a region setting unit which sets a first position information adding region at a first position defined based on at least any of the plurality of reference positions and a second position information adding region at a second position different from the first position, for each of the plurality of pictures; and

a position information embedding unit which embeds a first moving pattern which moves on the pictures in a first temporal period into the first position information adding region and a second moving pattern which moves on the pictures in a second temporal period into the second position information adding region.

2. The position information adding apparatus according to claim 1, wherein the second moving pattern is a pattern which is spatially different from the first moving pattern.

3. The position information adding apparatus according to claim 1, wherein the position information embedding unit moves the first moving pattern along a first direction and the second moving pattern along a second direction different from the first direction.

4. The position information adding apparatus according to claim 3, wherein the first moving pattern is a pattern in which a pixel value cyclically changes along the first direction and the second moving pattern is a pattern in which a pixel value cyclically changes along the second direction.

5. The position information adding apparatus according to claim 1, wherein the position information embedding unit sets the second temporal period to be different from the first temporal period.

6. The position information adding apparatus according to claim 1, further comprising a watermark information embedding unit which embeds digital watermark information in a region on each of the pictures, the region being determined based on at least two of the plurality of reference positions.

7. A position information adding method comprising:

setting a plurality of reference positions for each of a plurality of pictures contained in digitalized video data by a processor;

setting a first position information adding region at a first position defined based on at least any of the plurality of reference positions and a second position information adding region at a second position different from the first position, for each of the plurality of pictures by the processor;

embedding a first moving pattern which moves on the pictures in a first temporal period into the first position information adding region by the processor; and

embedding a second moving pattern which moves on the pictures in a second temporal period into the second position information adding region by the processor.

8. The position information adding method according to claim 7, wherein the second moving pattern is a pattern which is spatially different from the first moving pattern.

9. The position information adding method according to claim 7, wherein the embedding the first moving pattern moves the first moving pattern along a first direction and the embedding the second moving pattern moves the second moving pattern along a second direction different from the first direction.

10. The position information adding method according to claim 9, wherein the first moving pattern is a pattern in which a pixel value cyclically changes along the first direction and the second moving pattern is a pattern in which a pixel value cyclically changes along the second direction.

11. The position information adding method according to claim 7, wherein the embedding the second moving pattern sets the second temporal period to be different from the first temporal period.

12. The position information adding method according to claim 7, further comprising:

embedding digital watermark information in a region on each of the pictures, the region being determined based on at least two of the plurality of reference positions.

13. A non-transitory recording medium for recording a computer program which causes a computer to execute:

setting a plurality of reference positions for each of a plurality of pictures contained in digitalized video data;

setting a first position information adding region at a first position defined based on at least any of the plurality of reference positions and a second position information adding region at a second position different from the first position, for each of the plurality of pictures;

embedding a first moving pattern which moves on the pictures in a first temporal period into the first position information adding region; and

embedding a second moving pattern which moves on the pictures in a second temporal period into the second position information adding region.

14. A position detection apparatus for detecting a reference position on a picture which is contained in digitized video data, and in which a first moving pattern which moves in a first temporal period is embedded on a first position information adding region having a first positional relationship with the reference position and a second moving pattern which moves in a second temporal period is embedded on a second position information adding region having a second positional relationship with the reference position, the position detection apparatus comprising:

a feature quantity extracting unit which obtains a feature quantity for each pixel of the picture which represents at least either a movement of a pattern captured on a region containing the pixel or a spatial feature of the pattern;

an evaluation value calculating unit which obtains an evaluation value, for a predetermined region on the picture, representing a degree of likelihood that the predetermined region is at the reference position, based on the feature quantity of a pixel within a region having the first positional relationship with the predetermined region and the feature quantity of a pixel within a region having the second positional relationship with the predetermined region; and

a reference position detection unit which detects the reference position based on the predetermined region with a maximum evaluation value.

15. The position detection apparatus according to claim 14, wherein

for each pixel of the picture, the feature quantity calculating unit calculates, as the feature quantity, a motion vector of a pattern captured on a region containing the pixel, based on a positional difference between the pixel and a pixel at which a pixel value difference therebetween is minimum on an immediately preceding picture,

the evaluation value calculating unit sets the evaluation value high as a degree of matching between the first reference feature quantity which is a motion vector of the first moving pattern and the feature quantity of a pixel, which is a pixel on the picture, in a region having the first positional relationship with the predetermined region is high and a degree of matching between the second reference feature quantity which is a motion vector of the second moving pattern and the feature quantity of a pixel in a region having the second positional relationship with the predetermined region is high, and

the reference position detection unit detects, as the reference position, the predetermined region with a maximum evaluation value.

16. The position detection apparatus according to claim 14, wherein

for each pixel of the picture, the feature quantity calculating unit calculates, as the feature quantity, a frequency component of a first direction at a region containing the pixel and a frequency component of a second direction different from the first direction,

the evaluation value calculating unit sets the evaluation value high as a frequency component corresponding to a frequency component of the first direction of the first moving pattern, among the feature quantity of a pixel, which is a pixel on the picture, in a region having the first positional relationship with the predetermined region and a frequency component corresponding to a frequency component of the second direction of the second moving pattern, among the feature quantity of a pixel in a region having the second positional relationship with the predetermined region, and

the reference position detection unit detects, as the reference position, the predetermined region with a maximum evaluation value.

17. The position detection apparatus according to claim 14, wherein

the reference position is on a boundary of the first position information adding region and the second position information adding region,

for each pixel of the picture, the feature quantity calculating unit calculates, as the feature quantity, a motion vector of a pattern captured on a region containing the pixel, based on a positional difference between the pixel and a pixel at which a pixel value difference therebetween is minimum on an immediately preceding picture,

the evaluation value calculating unit sets, with respect to a row or a column of the picture in the predetermined region, a first region and a second region bounded by the row or the column, and obtains, as the evaluation value, a total of an average number of pixels for each row or column contained in the first region, the pixels having the feature quantity matching with the first reference feature quantity which corresponds to a motion vector of the first moving pattern and an average number of pixels for each row or column contained in the second region, the pixels having the feature quantity matching with the second reference feature quantity which corresponds to a motion vector of the second moving pattern, and

the reference position detection unit detects, as the reference position, an intersection of a row with a maximum evaluation value and a column with a maximum evaluation value.

18. The position detection apparatus according to claim 14, wherein digital watermark information is embedded into a watermark region having a third positional relationship with the reference position on the picture of the video data, and

the position detection apparatus further comprises a watermark information extracting unit which extracts the watermark information by analyzing a value of a pixel in a region having the third positional relationship with a pixel detected as the reference position by the reference position detection unit.