JP2006340326A - Method and apparatus for recording and reproducing information signal, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To embed a watermark in contents without degrading image quality or sound quality. <P>SOLUTION: An inputted video signal is compressed, the I picture in the video signal is separated, and search image data are generated by a search data generating section 13. Furthermore, additional information such as signature information or unique authentication information is converted into numerical information by a conversion section 18. In a WM superimposing section 14, the numerical information generated by the conversion section 18 is embedded in the search image data as a watermark. The watermark is embedded in the search image data, so that image quality of video data is not degraded. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an information signal recording method, an information signal reproducing method, an information signal recording apparatus, an information signal reproducing apparatus, and a program.

  2. Description of the Related Art DV (Digital Video) format recording / playback devices, such as camera recorders, for recording and playing back digital video signals are widely used. Furthermore, HD (High Definition) data (PES (Packetized Elementary Stream)) compressed with MP @ H-14 of MPEG (Moving Picture Coding Experts Group) -2 using the same DV format tape and rotating head. An apparatus for recording / reproducing is described in Patent Document 1. The content described in Patent Document 1 is called HDV2 standard.

JP 2002-314941 A

  By the way, if the various contents such as audio and video are illegally copied, the profit of the copyright holder is harmed. Therefore, improper use of the content is prevented by embedding user information or unique authentication information (hereinafter referred to as additional information as appropriate) as a watermark (digital watermark information) in the content.

  However, if a watermark is embedded in content such as audio data or video data, the sound quality of the audio data or the image quality of the video data may be degraded. Further, in the process of performing compression processing and decompression processing on audio data and video data, the watermark itself may be lost due to insufficient resistance of the watermark.

  A DV format tape used in the HDV2 standard is provided with a system data area called a video AUX (Auxiliary) or an audio AUX that records shooting date / time, camera F value, shutter value, and the like. This area is a so-called TOC (Table Of Contents) data area, and the recorded information may be easily taken out by the user. Therefore, there is a possibility that the additional information is tampered with. Further, when additional information is recorded in a cassette memory mounted on a tape, there is a problem that the information disappears when the memory unit is removed.

  Accordingly, an object of the present invention is to provide an information signal recording method capable of embedding additional information that is difficult to falsify in a recording medium and further reading without deteriorating the image quality and sound quality of video data and audio data recorded on the recording medium, An information signal reproducing method, an information signal recording device, an information signal reproducing device, and a program are provided.

  In order to solve the above-described problems, a first aspect of the present invention is an information signal recording method for compressing and encoding image data and recording the recording data on a recording medium. An extraction step for extracting image data, a search image data generation step for generating search image data by reducing the bit length of the luminance signal component and the color difference signal component of the image data extracted in the extraction step, and an additional input A conversion step for converting information into numerical information, an information embedding step for embedding numerical information in the search image data generated in the search image data generating step, and a search image data in which numerical information is embedded in the information embedding step Information recording method comprising a recording step of recording on a recording medium

  According to a second aspect of the present invention, in an information signal reproduction method for reproducing image data recorded on a recording medium, the image data recorded on the recording medium and the data recorded on the recording medium are distributed. A reproduction step for reproducing the search image data for variable speed reproduction, an extraction step for extracting numerical information embedded in the search image data, and at the time of normal reproduction, additional information is obtained by inversely converting the numerical information, This is an information signal reproduction method comprising a reproduction display step of reproducing and displaying additional information superimposed on image data and reproducing and displaying search image data during variable speed reproduction.

  According to a third aspect of the present invention, in an information signal recording apparatus that compresses and encodes image data and records the image data on a recording medium, an extraction unit that extracts image data for variable speed reproduction from the compression-encoded image data; A search image data generation unit that generates search image data by reducing the bit lengths of the luminance signal component and color difference signal component of the image data extracted by the extraction unit, and a conversion unit that converts input additional information into numerical information And an information embedding unit for embedding numerical information in the search image data generated by the search image data generating unit, and a record for recording the search image data in which the numerical information is embedded in the information embedding unit on a recording medium in a distributed manner Is an information signal recording device comprising a unit.

  According to a fourth aspect of the present invention, in an information signal reproducing apparatus for reproducing image data recorded on a recording medium, the image data recorded on the recording medium and the data recorded on the recording medium are distributed. A reproduction unit for reproducing search image data for variable speed reproduction, an extraction unit for extracting numerical information embedded in the search image data, an inverse conversion unit for acquiring additional information by inversely converting the numerical information, An information signal reproducing apparatus including a display control unit that displays additional information superimposed on image data.

  According to a fifth aspect of the present invention, there is provided an extraction step of extracting image data for variable speed reproduction from compression-encoded image data, and bits of a luminance signal component and a color difference signal component of the image data extracted in the extraction step A search image data generation step for generating search image data by reducing the length, a conversion step for converting input additional information into numerical information, and numerical information on the search image data generated in the search image data generation step Is an information embedding step, and a recording step for distributing and recording search image data in which numerical information is embedded in the information embedding step on a recording medium.

  According to a sixth aspect of the present invention, there is provided a reproduction step for reproducing image data recorded on a recording medium and search image data for variable speed reproduction recorded on the recording medium, and search image data The extraction step for extracting numerical information embedded in the image, and during normal playback, additional information is obtained by inversely converting the numerical information, and the additional information is reproduced and displayed superimposed on the image data. A program for causing a computer to execute a reproduction display step for reproducing and displaying image data.

  According to the present invention, it is possible to embed additional information that is difficult to tamper with in a recording medium without degrading the image quality of recorded video data and the sound quality of audio data. Further, the additional information embedded in the recording medium can be read out and reproduced and displayed.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration mainly related to processing of a video signal of a digital VTR (Video Tape Recorder) 1 to which the present invention can be applied. In order to simplify the description, the video signal processing will be mainly described, and the description regarding the audio signal processing will be omitted as appropriate.

  The digital VTR1 compresses, for example, HDV2 format 1440 × 1080 / 60i (interlace) video with MP @ H-14 with N = 15 (that is, 1 GOP (Group of Pictures) is composed of 15 frames). A search function for searching data at 8 times speed is provided.

  The input video signal is converted into a digital video signal by an A / D converter (not shown) and supplied to the video data compression unit 11. The video data compression unit 11 performs compression encoding processing on the input video data. For example, MP @ H-14 of MPEG2, as shown in FIG. 2, an I (Intra) picture is used for each frame in units of GOPs (GOP1, GOP2,... GOPn) each consisting of 15 frames. , B (Bidirectionally) pictures, or P (Predictive) pictures to generate compressed video data. The compressed video data is supplied to the I picture separation unit 12 and the format unit 15.

  The I picture separation unit 12 separates the I picture from the GOP as the search image. The separated I picture is supplied to the search data generation unit 13.

  The search data generation unit 13 generates search image data for a search image using the supplied I picture. Here, the search image data generated by the processing performed by the search data generation unit 13 will be described with reference to FIG.

  The number of effective pixels of luminance data of image data before encoding or after decoding is 1440 samples in the horizontal direction and 1080 samples in the vertical direction. The number of effective pixels of the color difference data is 720 samples in the horizontal direction and 540 samples in the vertical direction. As shown in FIG. 3, one screen of the search image for this image data has 90 (= 1440 ÷ 16) in the horizontal direction and 68 (1080 ÷ 16 (rounded up)) macroblocks (MB) in the vertical direction. ) Is formed.

  One macro block of the luminance signal Y is divided into four 8-pixel × 8-pixel DCT (Discrete Cosine Transform) blocks, and a DC (Direct Current) component is extracted from each DCT block and converted into 6-bit data. Is done. In addition, DC components are extracted from the DCT blocks of 8 pixels × 8 pixels of the color difference signal Cb and the color difference signal Cr, and converted into 5-bit data, respectively. After all, one macroblock is composed of 6 data, that is, 34 (= 6 bits × 4 + 5 bits × 2) bits. In this way, search image data corresponding to each GOP can be generated by processing the I-picture image data included in one GOP.

  Returning again to FIG. The watermark (WM) superimposing unit 14 embeds a watermark in the supplied search image data. Details of processing performed by the WM superimposing unit 14 will be described later.

  The watermark embedded in the search image data in the WM superimposing unit 14 is supplied from the conversion unit 18. For example, the user inputs additional information such as signature information or unique authentication information using a remote controller or a menu screen of the screen. The input additional information is converted into numerical information by the converter 18 and supplied to the WM superimposing unit 14. The WM superimposing unit 14 embeds this numerical information as a watermark in search image data.

  The format unit 15 adds an error correction code to the search image data input from the WM superimposing unit 14. As the error correction code, for example, a product code made up of C1 parity for dealing with errors during recording and reproduction and C2 parity which is an error correcting code for dealing with burst errors can be used. Also, an ID including data address information is added, and interleaving is performed between 16 tracks. Further, a sync pattern indicating the head of the packet is added to the search image data, predetermined modulation is performed, and P / S (parallel / serial) conversion is performed.

  The format unit 15 adds C1 and C2 error detection and correction codes and IDs to the compressed video data supplied from the video data compression unit 11, and performs interleaving processing between 16 tracks. Also, a sync pattern indicating the beginning of a packet is added to the input video data, predetermined modulation is performed, and P / S (parallel / serial) conversion is performed.

  The P / S converted video data and search image data are switched by a switch SW1 in accordance with a timing chart described later, and are recorded on the magnetic tape 16 by the rotary head 20. In the switch SW1, the connection between the terminals a and b is switched by a pulse signal sent from the AND gate 17.

  The data recorded on the magnetic tape 16 is read out as an analog electric signal by the rotary head 20, amplified by a reproduction amplifier, converted into a digital signal, and then the video data and search image data are selected by the switch SW2 and demodulated. Input to the unit 21. Switching of the connection between the terminal c side and the terminal d side of the switch SW2 is performed by a pulse signal sent from the AND gate 17.

  The demodulator 21 demodulates input data. The demodulated digital data is subjected to error correction based on the error detection codes of C1 and C2 during normal reproduction, and only C1 correction is performed during search reproduction, and ID is detected and deinterleave processing is performed.

  The error-corrected data is separated based on the sync block header, and the video data is output to the video data decompression unit 25 and the search image data is output to the search data detection unit 22.

  The video data decompression unit 25 performs a process of decompressing the input video data. The expanded video data is converted from digital data to analog data by a D / A converter 26 and supplied to an OSD (On Screen Display) control unit 27.

  In the search data detection unit 22, image processing is performed on the acquired search image data, and processing for generating search image data is performed. The search image data is output to the WM detection unit 23. The WM detection unit 23 performs processing for detecting a watermark embedded in the search image data.

  The inverse conversion unit 24 uses the watermark formed by the numerical information detected by the WM detection unit 23 to determine additional information that the numerical information means. The determined additional information is supplied to the OSD control unit 27. In the OSD 27 control unit, for example, processing for superimposing additional information supplied from the inverse conversion unit 24 on video data is performed, and predetermined video data is displayed on a monitor 28 such as a liquid crystal monitor.

  Next, a process for embedding additional information as a watermark in search image data will be specifically described. FIG. 4A is an example of a code table showing the correspondence between character information, which is additional information, and a value obtained by coding character information with 6 bits in this embodiment. For example, a total of 52 upper and lower case letters are used for the character information. The character size and style displayed on the monitor are predetermined. The correspondence between the character information shown in FIG. 4A and the code table is stored in the memory 19 shown in FIG. 1, for example. In this embodiment, the character information is set as 52 characters. However, when 6 macroblocks are used, up to 63 characters can be set. It is also possible to use non-alphabetic characters, pictograms, icons and the like.

  FIG. 4B shows the correspondence between the character code to be embedded and the macro block (MB). Each bit “0” or “1” of the 6-bit character code information is embedded in 6 macroblocks (indicated as MB0 to MB5). For example, when character information “A” is embedded, it is as follows. The character code of the character information “A” is “000001” from the code table of FIG. 4A. This character code is embedded in each macro block based on the correspondence in FIG. 4B. That is, “1” which is information of bit 0 is embedded in MB0, and “0” which is information of bits 1 to 5 is embedded in MB1 to MB5. In this way, one character information is embedded using six macro blocks.

  For example, when the user embeds his / her signature information, the user selects a desired character by operating a menu screen or a remote controller displayed on the monitor. The input characters are subjected to predetermined processing by an input unit (not shown), and a signal indicating a user operation is output from the input unit to the conversion unit 18.

  The conversion unit 18 reads character information from a signal indicating a user operation, and reads a character code corresponding to the character information from the memory 19. The character code read from the memory 19 is supplied to the WM superimposing unit 14.

  The WM superimposing unit 14 embeds the character code supplied from the converting unit 18 in the DCT block constituting the macro block of the search image data supplied from the search data generating unit 13.

  FIG. 5 shows the structure of a macro block of search image data. As described above, the macro block of the search image data is composed of six DCT blocks including the DCT block Y0 to DCT block Y3, the DCT block Cr, and the DCT block Cb. FIG. 5 shows each DCT block, S (i, j) is a DCT coefficient, 0 ≦ i ≦ 7 indicates a horizontal frequency component, and 0 ≦ j ≦ 7 indicates a vertical frequency component.

  When the character code “0” is embedded, as shown in FIG. 6, among the six DCT blocks of the macroblock, the DCT in the high frequency region where the macroblock Y0, the macroblock Y2, and the macroblock Cr are hatched. Manipulate the coefficients. For example, the value of the DCT coefficient is replaced with 0. No operation is performed on the DCT coefficients of the macroblock Y1, the macroblock Y3, and the macroblock Cb.

  On the other hand, when the character code “1” is embedded, as shown in FIG. 7, among the six DCT blocks of the macroblock, the macroblock Y1, the macroblock Y3, and the macroblock Cb are hatched. Manipulate the DCT coefficients. For example, the value of the DCT coefficient is replaced with 0. No operation is performed on the DCT coefficients of the macro block Y0, the macro block Y2, and the macro block Cr.

  In the example shown in FIGS. 6 and 7, the coefficients after the 28th coefficient S (0,7) when the DCT coefficients are zigzag scanned are replaced with 0 as the coefficients in the high frequency region. It is appropriately determined by comprehensively considering the information amount of the DCT block, the detection accuracy during reproduction, the picture search image quality, and the like. The combination of DCT blocks in which the character code information bits “0” and “1” are embedded is not limited to the above-described example, and other combinations may be used.

  As conceptually shown in FIG. 8, the six DCT blocks constituting one macroblock are divided into two groups, and the high-frequency region coefficient of any group is manipulated to make the character code information bits “0” or “1”. Embedded. Since this process can be known only by the user, it becomes a secret key in this embodiment.

  Next, a process of recording a macro block in which information bits of character codes are embedded on the magnetic tape 16 will be described.

  FIG. 9 shows the structure of search image data and its header. The basic unit of data recorded on the magnetic tape 16 is one sync block (SB), and one sync block is composed of 21 macroblocks MB0 to MB20.

  As described above, 1-bit character code is embedded in one macroblock. Of the 21 macroblocks constituting one sync block, the first macroblocks MB0 to MB5 are used to embed character codes. In addition, a 1-bit flag indicating whether or not there is an information bit of the character code is recorded in a reserved area (meaning an undefined area) of the header of search image data added for each sync block. For example, when the 1-bit flag is “1”, the character code information bit “present” is indicated, and when the flag is “0”, the information bit “not present” is indicated. At the time of reproduction, it is possible to extract macro block information in the sync block based on the information indicated by the header flag of the sync block.

  FIG. 10A shows a track pattern on the magnetic tape 16, and FIG. 10B shows a track format of the magnetic tape 16. The track pattern and the track format shown in FIGS. 10A and 10B are of the HD @ 2 standard MP @ H-14 system.

  Each time the rotary head 20 traces once, a preamble (Preamble: Pr), main data (Main data: M), a subcode sector (Sub code sector: S), and a postamble (Post amble: Po) are recorded. . Then, one ECC (Error Correcting Code) interleaving unit is configured by 16 tracks, and error correction is performed for each ECC interleaving unit. Accordingly, splicing and editing on the tape 16 are also executed for each ECC interleave unit.

  FIG. 11A shows an example of the arrangement of search image data areas when the speed ratio is 8. In the search operation, the tape feeding speed is higher than that at the time of recording, and the rotary head reproduces data in pieces across a plurality of tracks. Therefore, the search image data is arranged at a position where the search image data is always reproduced at a predetermined speed ratio, for example, 8 times speed. In FIG. 11A, vertical stripes indicate the tracks on the magnetic tape, and diagonal lines indicate the operation trajectory of the rotary head at 8 × speed. As shown in the figure, the search image data is arranged at a position where the rotary head traces at 8 × speed. Note that the speed ratio is not limited to 8, and may be a value of speed ratios such as 16, 24, etc., and one of a plurality of speed ratios may be selected by the user.

  In one search image data area recorded on the tape, 17 sync block search image data SB0 to SB16 are inserted. In the case of 8 × speed, 2 areas (34 (= 17 × 2) sync blocks) in track 1 and 3 areas (51 (= 17 × 3) sync blocks) in track 3 in 16 tracks which are ECC interleave units, track 5 2 areas (34 (= 17 × 2) sync blocks) are recorded. As shown in FIG. 11B, search image data for 9 traces are arranged over 144 tracks.

  Since one character is embedded in one sync block, 17 characters correspond to one area (17 sync blocks) of the search image data. Since there are seven search image data areas in one ECC interleave unit, 17 character information is repeatedly embedded seven times. In addition, since there are nine search image data areas in 1 GOP (144 tracks), 17-character information is repeatedly embedded 63 (= 7 × 9) times. By repeatedly embedding character information in this way, it is possible to improve the efficiency of detecting character information during reproduction.

In this embodiment, six macroblocks out of macroblocks constituting one sync block can be used to represent a maximum of 63 types of characters with 6 bits. up to 21 bits to be composed of macroblocks, it is possible to handle two ²¹ kinds of characters in characters.

  FIG. 12A shows a switching mode table for each of the switches SW1 and SW2 in the configuration shown in FIG. 1, and FIG. 12B shows a time chart for switching each of the switches SW1 and SW2. A pulse signal TRP, which is a track pulse, is input to one input gate of the AND gate 17. Further, any one of the pulse signal TR1, the pulse signal TR3, and the pulse signal TR5 is input to the other input gate.

  For example, when the pulse signal TRP and the pulse signal TR1 are both H, the pulse signal output from the AND gate 17 is H. When the output pulse signal of the AND gate 17 is H, the switch SW1 is connected to the terminal b side, and the switch SW2 is connected to the terminal d side. When both the pulse signal TRP and the pulse signal TR1 are not H, the pulse signal output from the AND gate 17 is set to L. When the output pulse signal of the AND gate 17 is L, the switch SW1 is connected to the terminal a side, and the switch SW2 is connected to the terminal c side. Similarly, when the pulse signal TR3 and the pulse signal TR5 are input to one input gate of the AND gate 17, the switch SW1 and the switch SW2 are switched.

  Accordingly, as shown in FIG. 12B, when the pulse signal TRP and the pulse signal TR1 (or the pulse signal TR3 and the pulse signal TR5) are both H, search image data is recorded on the magnetic tape 16, and in other cases. In addition, video data is recorded on the magnetic tape 16.

  Next, detection of information bits of a character code, which is an example of a watermark embedded in search image data during normal reproduction, and processing for displaying characters on a monitor based on the detected information bits will be described.

  During normal reproduction, a signal is read out by the rotary head 20 in accordance with the tape pattern shown in FIG. 11A, and video data and search image data are selected at the timing shown in FIGS. 12A and 12B by the switch SW2.

  The switch SW2 is connected to the terminal c side, and the above-described processing is performed on the video data read from the magnetic tape 16 in each of the demodulator 21, video data decompressor 25, D / A converter 26, and OSD controller 27. Is output to the monitor 28. At this time, since the information bits of the character code are not embedded in the video data, there is no problem such as deterioration in image quality caused by embedding the information bits.

  The switch SW2 is connected to the terminal d side, and the search image data read from the magnetic tape 16 is subjected to processing such as data separation and error correction in the demodulator, and is output to the search data detector 22. The search data detection unit 22 detects a 1-bit mode flag indicating the presence or absence of information embedded in the reserved area of the header information of the sync block. At this time, if the mode flag is “0”, it is assumed that there is no embedded information, and the following processing is not performed.

  When the mode flag is “1”, the WM detection unit 23 performs the following processing. In the WM detection unit 23, 17 sync blocks (357 (= 17 × 21) macroblocks) acquired from the track 1 are obtained twice for each ECC interleave unit (16 tracks) and 17 sync blocks (357 are acquired from the track 3). (= 17 × 21) macroblock) is detected three times, and 17 sync blocks (357 (= 17 × 21) macroblock) acquired from the track 5 are detected twice.

  In addition, the WM detection unit 23 compares the energy in the high frequency region of the six DCT blocks constituting each macroblock of the first macroblocks MB0 to MB5 among the 21 macroblocks constituting the detected sync block. The energy in the high frequency region is calculated by, for example, the sum of squares of the DCT coefficients in the high frequency region after S (0,7) described with reference to FIGS.

  For example, the energy of the DCT block Y0 (hereinafter referred to as EY0 as appropriate) and the energy of the DCT block Y1 (hereinafter referred to as EY1 as appropriate) are expressed as the energy of the DCT block Y2 (hereinafter referred to as EY2 as appropriate). ) And the energy of the DCT block Y3 (hereinafter referred to as EY3 as appropriate), the energy of the DCT block Cr (hereinafter referred to as ECr) and the energy of the DCT block Cb (hereinafter referred to as ECb as appropriate). ) And each.

As a result of comparison, when all of the following formulas (1) to (3) hold, the character code information bit “0” is embedded in the macro block composed of these six DCT blocks. It is determined that
EY0 <EY1 (1)
EY2 <EY3 (2)
ECr <ECb (3)

As a result of comparison, if all of the following formulas (4) to (6) hold, the character code information bit “1” is embedded in the macro block composed of these six DCT blocks. It is determined that
EY0> EY1 (4)
EY2> EY3 (5)
ECr> ECb (6)

  When the information bit “0” or “1” is embedded in the macro block, the coefficient in the high frequency region of one group of DCT blocks (for example, DCT block Y0, DCT block Y2, and DCT block Cb) is replaced with 0. Therefore, one of the information bits “0” and “1” can be determined by the above-described comparison.

  The WM detection unit 23 determines information bits embedded in MB0 to MB5 of each sync block, and the determination result is supplied to the inverse conversion unit 24. The inverse conversion unit 24 determines a character code using, for example, a table showing the correspondence between macroblocks and character codes shown in FIG. 4B. Then, referring to the code table recorded in the memory 19, character information to be displayed on the screen is determined from the character code.

  The determined character information is supplied to the OSD control unit 27. The OSD control unit 27 performs processing for superimposing character information on video data.

  FIG. 13 shows a display example of embedded character information. The monitor 41 displays a video in which character information is multiplexed on video data. The monitor 41 is provided with a display area 42 for displaying characters for each sync block number of 17 sync blocks. For example, if the character code representing “Y” is embedded in SB0 among the 17 sync blocks, the character “Y” is displayed in the display area 43 of SB0. This indicates that no character code is embedded in the sync block corresponding to the blank display area. In this way, additional information such as signature information and unique authentication information such as “YaMaDa TaRo” can be displayed on the screen. Note that the font, type, and display position of characters displayed on the screen are not limited to the example shown in FIG.

  For example, the following processing is performed at the time of 8 × speed variable speed reproduction. At the time of variable speed reproduction, tracing by the rotary head is performed as shown in FIGS. 11A and 11B, and the traced signal is amplified by a reproduction amplifier (not shown) and subjected to demodulation processing by the demodulator 21. Further, error correction processing and deinterleaving processing are performed. Then, the search image data detected by the search data detection unit 22 is converted into a video signal that can be analog output by a search image data processing unit (not shown) and a memory for variable speed reproduction, and then subjected to expansion processing and D / A conversion processing. It is output to the monitor as a search image. During variable speed reproduction, detection of information bits embedded in the search image data is not performed.

  As described above, information bits are embedded in the search image data. Therefore, when the search image data is displayed as a search image on the monitor, the image quality may be deteriorated. However, since the search image data is used as a search image at the time of variable speed reproduction or the like, a reduction in image quality is allowed. Furthermore, since the watermark is embedded by manipulating the high-frequency region coefficient of the DCT coefficient, it is possible to reduce the deterioration of the image quality of the search image data.

  The embodiment of the present invention has been specifically described above, but the present invention is not limited to the above-described embodiment, and various modifications based on the technical idea of the present invention are possible. For example, the above-described recording process, reproduction process, search image data generation / restoration process, and the like may be performed using either hardware or software. The processing performed by the conversion unit 18 and the inverse conversion unit 24 may be performed by a CPU (Central Processing Unit) realized by, for example, a microcomputer.

  Furthermore, the present invention can also be applied when using a recording medium such as an optical disk or an optical tape other than the magnetic tape.

It is a block diagram which shows an example of a structure of digital VTR in one Embodiment of this invention. It is a basic diagram used for description of the time-axis structure of search image data. It is a basic diagram used for description of search image data. It is a basic diagram which shows a response | compatibility at the time of representing the character used in one Embodiment of this invention and each character by 6 bits, and a response | compatibility with each macroblock and a character code. It is a basic diagram which shows an example of a structure of each macroblock. It is a basic diagram used for description of the process which embeds information bit "0" in a macroblock. It is a basic diagram used for description of the process which embeds information bit "1" in a macroblock. It is a basic diagram used for description of the process which embeds an information bit. It is a basic diagram which shows the structure of 1 sync block. It is a basic diagram which shows the track format of the magnetic tape in one Embodiment of this invention. It is a basic diagram which shows the example of arrangement | positioning of the search image data in one Embodiment of this invention. It is the mode table and time chart for demonstrating switching of switch SW1 and switch SW2. It is a basic diagram which shows the example of a display of the character information in one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Video data compression part 12 I picture separation part 13 Search data generation part 14 WM superimposition part 16 Magnetic tape 18 Conversion part 19 Memory 22 Search data detection part 23 WM detection part 24 Inverse conversion part 27 OSD control part 28 Monitor

Claims (8)

In an information signal recording method for compressing and encoding image data and recording it on a recording medium,
An extraction step of extracting image data for variable speed reproduction from the compression encoded image data;
A search image data generation step for generating search image data by reducing the bit length of the luminance signal component and the color difference signal component of the image data extracted in the extraction step;
A conversion step of converting input additional information into numerical information;
An information embedding step of embedding the numerical information in the search image data generated in the search image data generation step;
An information signal recording method comprising: a recording step in which search image data in which the numerical information is embedded in the information embedding step is distributed and recorded on a recording medium. In claim 1,
The information embedding step is an information signal recording method in which the numerical information is embedded by manipulating a coefficient in a high frequency region of an encoding block constituting the search image data. In an information signal reproduction method for reproducing image data recorded on a recording medium,
A reproduction step for reproducing the image data recorded on the recording medium and the search image data for variable speed reproduction recorded in a distributed manner on the recording medium;
An extraction step of extracting numerical information embedded in the search image data;
During normal playback, additional information is obtained by inversely transforming the numerical information, and the additional information is superimposed on the image data and displayed.
An information signal reproduction method comprising a reproduction display step of reproducing and displaying the search image data during variable speed reproduction. In claim 3,
The information signal reproducing method, wherein the extracting step is a step of extracting additional information using a sum of squares of coefficients in a high frequency region of a coding block constituting the search image data. In an information signal recording apparatus for compressing and encoding image data and recording it on a recording medium,
An extraction unit for extracting image data for variable speed reproduction from the compression-encoded image data;
A search image data generation unit that generates search image data by reducing the bit length of the luminance signal component and the color difference signal component of the image data extracted by the extraction unit;
A conversion unit that converts input additional information into numerical information;
An information embedding unit for embedding the numerical information in the search image data generated by the search image data generation unit;
An information signal recording apparatus comprising: a recording unit for distributing and recording search image data in which the numerical information is embedded in the information embedding unit on a recording medium. In an information signal reproducing apparatus for reproducing image data recorded on a recording medium,
A reproduction unit for reproducing image data recorded on the recording medium and search image data for variable speed reproduction recorded on the recording medium in a distributed manner;
An extraction unit for extracting numerical information embedded in the search image data;
An inverse conversion unit that acquires additional information by inversely converting the numerical information;
An information signal reproducing apparatus comprising: a display control unit that displays the additional information superimposed on the image data. An extraction step of extracting image data for variable speed reproduction from the compression encoded image data;
A search image data generation step for generating search image data by reducing the bit length of the luminance signal component and the color difference signal component of the image data extracted in the extraction step;
A conversion step of converting input additional information into numerical information;
An information embedding step of embedding the numerical information in the search image data generated in the search image data generation step;
A program that causes a computer to execute a recording step of distributing and recording search image data in which the numerical information is embedded in the information embedding step on a recording medium. A reproduction step for reproducing the image data recorded on the recording medium and the search image data for variable speed reproduction recorded in a distributed manner on the recording medium;
An extraction step of extracting numerical information embedded in the search image data;
During normal playback, additional information is obtained by inversely transforming the numerical information, and the additional information is superimposed on the image data and displayed.
A program for causing a computer to execute a reproduction display step of reproducing and displaying the search image data during variable speed reproduction.

Images