JP2002152690A - Scene change point detecting method, scene change point presenting device, scene change point detecting device, video reproducing device and video recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a scene change point while securely improving the convenience of a user independently of the type of videos. SOLUTION: The change point is extracted from the candidates of the scene change points so that mutual time internals become appropriate. Information showing the genre ('sports' and 'interview', for example') of the video is set at the time of reserving recording, for example. A picture where a difference (the difference of a value based on a DCT coefficient in the case of MPEG, for example) with a candidate picture just before exceeds a threshold which is set in accordance with the genre of the video is specified from the candidate picture ( an I picture in the case of MPEG, for example) of the scene change point included in the picture constituting the video is specified. The appearing time of the picture is detected as the scene change point. Thus, the scene change points whose intervals are appropriate with respect to any type of the videos are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scene change point detecting method and a scene change point detecting apparatus for detecting a scene change point from an image including a plurality of scenes (a unit image in which the same scene is temporally continuous). The present invention relates to a scene switching point presenting apparatus for presenting detected switching points, a video reproducing apparatus for starting video reproduction from a desired switching point, and a video recording apparatus for recording the detected switching points in a usable manner.

[0002]

2. Description of the Related Art In recent years, hard disks and DVDs (Digita
An apparatus has been developed which records a video such as a television program on a random accessible recording medium such as a Versatile Disc, and reproduces the video. Among these types of devices, a device that creates a still image representing a scene at the time of recording, displays the still images in the recording order, and starts playback of the recorded video from the scene corresponding to the still image specified by the user. Exists. Such devices typically scan video data,
A scene switching point detection method of detecting a time point at which a change in pixel value between frames forming video data is large as a scene switching point is employed.

[0003]

However, in the conventional scene switching point detection method, a point in time at which a change in pixel value between frames is large is always detected as a scene switching point. For this reason, when a scene switching point is detected for a program such as a sports broadcast where scenes are frequently switched,
An extremely large number of time points are detected as scene switching points, and the burden on the user when specifying a desired scene increases. On the other hand, when the conventional scene switching point detection method is applied to a program such as an interview program in which scene switching is small, only a very small number of scene switching points are detected, and the burden on the user when specifying a desired scene is also increased. It gets bigger. That is, the conventional scene switching point detection method has a problem that depending on the type of video, the improvement in user convenience that should be achieved by detecting the scene switching point is not achieved.

[0004] The present invention has been made in view of the above circumstances, and a scene switching point detecting method and a scene switching point presenting apparatus capable of reliably improving the user's convenience without depending on the type of video. It is another object of the present invention to provide a scene switching point detecting device, a video reproducing device, and a video recording device.

[0005]

According to a first aspect of the present invention, there is provided a method for detecting a scene switching point, comprising the steps of: selecting a scene switching point from a video composed of a plurality of images continuous on a time axis; In the scene switching point detection method, wherein the switching points are extracted from the switching point candidates such that the time intervals between the switching point candidates are appropriate.

According to a second aspect of the present invention, there is provided a scene switching point detecting method for detecting a scene switching point from a video composed of a plurality of continuous images on a time axis. The content acquisition step of acquiring information indicating the content, and among the target images that can be the switching point in the video, the difference from the immediately preceding target image is outside the range based on the information acquired in the content acquisition step. And a detecting step of detecting a time point according to the target image selected in the specifying step as the switching point.

According to a third aspect of the present invention, there is provided a scene switching point detecting method for detecting a scene switching point from a video composed of a plurality of continuous images on a time axis. A difference specifying step of obtaining a difference between the target image that can be the switching point and the immediately preceding target image, and a batch specifying step of specifying a preset number of target images in descending order of the difference obtained in the difference specifying step And a batch detection step of detecting a time point according to the target image specified in the specifying step as the switching point.

According to a fourth aspect of the present invention, there is provided a scene switching point detecting method for sequentially detecting scene switching points along a time axis from a video composed of a plurality of continuous images on a time axis. In the method, when the difference between the target image that can be the switching point in the video and the immediately preceding target image is within a range, the range is narrowed, and when the difference is outside the range, the time according to the target image is determined. It is characterized in that it is detected as a switching point and the range is expanded.

The present invention also provides a scene switching point presentation device for detecting and presenting a scene switching point from a video composed of a plurality of continuous images on a time axis. A range setting unit that sets information representing a range, an input unit that inputs the video, and a difference that obtains a difference between a target image that can be the switching point in the video input by the input unit and a previous target image. A calculating unit, a specifying unit that specifies a target image outside the range according to the information set by the range setting unit, wherein the difference obtained by the difference calculating unit is determined according to the target image specified by the specifying unit. And a presentation unit that presents the switching point detected by the detection unit.

The present invention also provides a scene switching point presentation device for detecting and presenting a scene switching point from a video composed of a plurality of images continuous on a time axis. A number setting unit for setting information indicating the number of the switching points to be detected; an input unit for inputting the video; and an immediately preceding target image which may be the switching point in the video input by the input unit. A difference calculation unit for obtaining a difference from the target image, a batch specifying unit for specifying the number of target images according to the information set by the number setting unit in descending order of the difference obtained by the difference calculation unit, and the batch A batch detection unit that detects a point in time according to the target image specified by the specifying unit as the switching point, and a presentation unit that presents the switching point detected by the batch detection unit. It is characterized.

A scene switching point presentation device according to a seventh aspect of the present invention is a scene switching point presentation device for detecting and presenting a scene switching point from a video composed of a plurality of images continuous on a time axis. An input unit that inputs the video, a difference calculation unit that obtains a difference between a target image that can be the switching point in the video and a previous target image, and the difference that is obtained by the difference calculation unit is set in advance. A specifying unit that specifies a target image outside the range, a detecting unit that detects a time corresponding to the target image specified by the specifying unit as the switching point, and a presentation that presents the switching point detected by the detecting unit And a range changing unit that narrows the range when the difference calculated by the difference calculation unit is within the range, and expands the range when the difference is out of the range. .

A scene switching point detecting device according to claim 8 is a scene switching point detecting device for detecting a scene switching point from a video composed of a plurality of images that are continuous on a time axis. A range setting section for setting information;
An input unit that inputs the video, a difference calculation unit that obtains a difference between a target image that can be the switching point in the video input by the input unit and a previous target image, and a difference calculation unit that obtains the difference. A specifying unit that specifies a target image outside the range according to the information set by the range setting unit, and a detecting unit that detects a time point according to the target image specified by the specifying unit as the switching point. And an output unit for outputting information indicating the switching point detected by the detection unit.

A scene switching point detecting apparatus according to a ninth aspect of the present invention is a scene switching point detecting apparatus for detecting a scene switching point from a video composed of a plurality of images continuous on a time axis. A number setting unit for setting information indicating the number of the switching points to be performed, an input unit for inputting the video, and a target image immediately before the target image which can be the switching point in the video input by the input unit. A difference calculation unit for calculating the difference, a collective specifying unit for specifying the number of target images according to the information set by the number setting unit in the descending order of the difference calculated by the difference calculation unit, and the collective specifying unit A batch detection unit that detects a point in time according to the specified target image as the switching point; and an output unit that outputs information indicating the switching point detected by the batch detection unit. It is characterized in.

According to a tenth aspect of the present invention, there is provided a scene switching point detecting device for detecting a scene switching point from a video composed of a plurality of images continuous on a time axis. An input unit for inputting, a difference calculation unit that calculates a difference between the target image that can be the switching point in the video and the immediately preceding target image, and the difference calculated by the difference calculation unit that is outside a preset range. A specifying unit that specifies a target image; a detecting unit that detects a point in time according to the target image specified by the specifying unit as the switching point; and an output that outputs information indicating the switching point detected by the detecting unit. And a range changing unit that narrows the range when the difference calculated by the difference calculation unit is within the range, and expands the range when the difference is out of the range. There.

Further, the video reproducing apparatus according to the present invention detects and presents a scene switching point from a video composed of a plurality of images that are continuous on a time axis, and presents the scene switching point from a switching point designated by a user. In a video playback device that starts playback of a video, an instruction input unit for inputting a user's instruction, a video storage unit that stores the video, a range setting unit that sets information indicating a range, A difference calculation unit for obtaining a difference between the target image that can be the switching point and the immediately preceding target image, and a target image outside the range according to the information set by the range setting unit, where the difference obtained by the difference calculation unit is set. A detecting unit that detects a time point according to the target image specified by the specifying unit as the switching point; a presenting unit that presents the switching point detected by the detecting unit; It is characterized in that the switching point in response to an instruction and input by the input unit and the presentation contents of the part includes a reproduction unit for reproducing the video.

A video reproducing apparatus according to a twelfth aspect of the present invention detects and presents a scene switching point from a video composed of a plurality of images that are continuous on a time axis, and displays the scene switching point from a switching point designated by a user. In a video playback apparatus for starting playback of a video, an instruction input unit for inputting a user's instruction, a video storage unit storing the video, and a number for setting information indicating the number of the switching points to be detected A setting unit, a difference calculation unit that obtains a difference between the target image that can be the switching point in the video and the immediately preceding target image, and the number setting unit that sets the difference obtained by the difference calculation unit in descending order. A batch specifying unit that specifies a number of target images according to the information, and a batch detecting unit that detects a time point according to the target image specified by the batch specifying unit as the switching point,
A presentation unit that presents a switching point detected by the batch detection unit; and a playback unit that plays back the video from a switching point corresponding to the presentation content of the presentation unit and an instruction input by the input unit. It is characterized by:

A video reproducing apparatus according to a thirteenth aspect detects and presents a scene change point from a video composed of a plurality of images that are continuous on a time axis, and presents the scene change point from a change point designated by a user. In a video playback apparatus for starting playback of a video, an instruction input unit for inputting a user's instruction, a video storage unit storing the video, and a target image immediately before the target image that can be the switching point in the video A difference calculation unit for determining a difference between the difference calculation unit, the difference calculated by the difference calculation unit, a specifying unit that specifies a target image outside a preset range, and a time point according to the target image specified by the specifying unit. A detection unit that detects the switching point, a range change unit that narrows the range when the difference calculated by the difference calculation unit is within the range, and expands the range when the difference is outside the range, Previous A presentation unit that presents the switching point detected by the detection unit, and a playback unit that plays back the video from the switching point according to the presentation content of the presentation unit and the instruction input by the input unit. Features.

Further, a video recording apparatus according to the present invention detects a scene switching point from a video composed of a plurality of images continuous on a time axis, and associates information indicating the switching point with the video. An image input device for inputting an image, an image storage unit for storing an image input from the input unit, a range setting unit for setting information representing a range, and the switching in the image. A difference calculation unit that calculates a difference between the target image that can be a point and the immediately preceding target image, and a target image that is outside the range according to the information set by the range setting unit, where the difference calculated by the difference calculation unit is specified. A switching unit that detects a point in time corresponding to the target image specified by the specifying unit as the switching point, and associates information representing the switching point detected by the detection unit with the video data. It is characterized by comprising a switching point storage unit for storing Te.

Further, the video recording apparatus according to the present invention detects a scene switching point from a video composed of a plurality of continuous images on a time axis, and associates information indicating the switching point with the video. An input unit for inputting an image, an image storage unit for storing an image input from the input unit, and a number setting unit for setting information indicating the number of the switching points to be detected. And a difference calculation unit that obtains a difference between the target image that can be the switching point in the video and the immediately preceding target image, and information set by the number setting unit in descending order of the difference obtained by the difference calculation unit. A collective specifying unit that specifies a corresponding number of target images; a collective detecting unit that detects a point in time according to the target images specified by the collective specifying unit as the switching point; Is characterized by comprising a a switching point storage unit information indicating a switching point in association with the video data.

A video recording apparatus according to a sixteenth aspect detects a scene switching point from a video composed of a plurality of images continuous on a time axis, and associates information indicating the switching point with the video. In the video recording device for recording the video, an input unit for inputting a video, a video storage unit for storing the video input from the input unit, and A difference calculation unit for obtaining a difference, a specifying unit for specifying the target image outside the preset range, wherein the difference obtained by the difference calculation unit, and a time corresponding to the target image specified by the specifying unit, A detection unit that detects the switching point, a switching point storage unit that stores information indicating the switching point detected by the detection unit in association with the video data, and the difference obtained by the difference calculation unit. Narrowing the range in the case of the serial range, if outside the range is characterized by comprising a range change unit to expand the range.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] A: Function First, the function of the video recording apparatus according to the first embodiment of the present invention will be described. This video recording device is an EPG (Electronic Program Guide) for terrestrial television broadcasting and satellite television broadcasting.
EPG reception function for receiving and managing a program, broadcast reception function for receiving a desired program, recording reservation function for making a program recording reservation, reservation recording function for recording a program according to the recording reservation, and recording video. It has a scene presenting function for presenting a scene switching point and a reproducing function for reproducing a recorded video from an arbitrary scene switching point.

B: Configuration FIG. 1 is a block diagram showing the configuration of the video recording apparatus according to the first embodiment of the present invention. In this figure, reference numeral 101 denotes a bus to which each unit is connected, 102 denotes a CPU (central processing unit) that includes a plurality of registers and cache memories, and performs various arithmetic processes and controls each unit described later. Various programs and CPU 10
ROM that stores various parameters to be read in
(Read Only Memory) 104 is a RAM (Random Access Memory) used as a work memory of the CPU 102.
y), 105 is a hard disk (video storage unit) for storing various data, and 106 is an operation unit (instruction input unit) provided with an operation unit operated by the user, and a signal corresponding to the operation content of the operation unit Is output to the bus 101. Reference numeral 107 denotes a battery-backed timer, which has a built-in real-time clock for measuring the current time, and outputs an interrupt signal to the bus 101 for bringing the CPU 102 into an operating state a predetermined time before the date and time set by the CPU 102. I do.

Reference numeral 108 denotes a video input unit (input unit) which receives a terrestrial TV signal input terminal for receiving terrestrial TV broadcasts, and selects and receives one video signal from signals input to this input terminal. Terrestrial television broadcast receiver, an MPEG2 encoder for converting a video signal selected by the terrestrial television broadcast receiver into a digital format of the MPEG2 format, and outputting the digital signal to the bus 101; The EPG is received, converted to a digital format, and converted to a bus 101
Terrestrial EPG receiver to be output to a TV, a satellite TV signal input terminal for receiving a satellite TV broadcast, and one MPEG2 format video data extracted from the video signal input to this input terminal and output to the bus 101 In addition, a satellite television broadcast receiver that receives an EPG input to a satellite television signal input terminal, converts the received EPG into a digital format, and outputs the digital format to the bus 101 is included. The selection of a video signal to be received by the terrestrial television broadcast receiver and the extraction of video data by the satellite television broadcast receiver are controlled by the CPU 102.

Reference numeral 109 denotes a frame memory capable of storing a predetermined number of frames of uncompressed digital video data supplied via the bus 101, and 110 denotes an analog output unit which converts the digital video data stored in the frame memory 109 The signal is converted into an analog signal (for example, an NTSC signal) and output to an external display.

Reference numeral 111 denotes a frame memory capable of storing a predetermined number of frames of digital video data supplied via the bus 101; 112, a display control unit; 113, an internal display such as a liquid crystal display; The internal display 113 is controlled so that an image corresponding to the digital image data stored in the frame memory 111 is displayed on the internal display 113.

The CPU 102 has an interrupt waiting state in which it waits for an interrupt signal via the bus 101 and an operating state in which each unit can be controlled, and switches its own state in response to pressing a power button (not shown). In addition, the CPU 10
Upon receiving an interrupt signal from the timer 107 via the bus 101, the device 2 sets its own state to the operating state. At this time, C
The PU 102 acquires the current time from the timer 107, and counts the current time until the next wait state for the interrupt. When any event (for example, operation of the operation unit 106) occurs in the operating state, the CPU 102 performs the processing corresponding to the event to realize the above function. Hereinafter, various functions realized mainly by the CPU 102 will be individually described.

(1) EPG Reception Function First, the EPG reception function will be described. CPU102
When the video input unit 108 receives the EPG,
To update the EPG file on the hard disk 105. In the present embodiment, a plurality of pieces of program information are stored in the EPG, and each piece of program information includes the items illustrated in FIG. 2 (identification number, broadcast station, start date and time, end date and time, genre, program name,...). Information is stored. The EPG file is a file in which the above-mentioned program information is stored without duplication. The CPU 102 refers to each identification information in the received EPG, adds the program information not stored in the EPG file, and adds the program information already stored in the EPG file. The EPG file is updated by overwriting the existing program information. In the present embodiment, since the identification information in the terrestrial television broadcast program information and the identification information in the satellite television broadcast program information do not overlap,
Both can be treated in a unified manner.

(2) Recording Reservation Function Next, the recording reservation function will be described separately for a recording reservation function using the EPG and a recording reservation function by manual setting. In the case of recording reservation using the EPG, the CPU 102
EPG file on hard disk 105 and operation unit 10
6, a user interface (see FIG. 3) for making a recording reservation using the EPG is provided based on the input signal from the EPG 6. The reservation information (see FIG. 5) is generated based on the file (see FIG. 4) and stored in the reserved area on the hard disk 105. Further, the CPU 102 sets the start date and time in the reservation information stored in the reservation area on the hard disk 105 in the timer 107, and sets the timer 107 to be in the operating state a predetermined time before the start date and time.

As shown in FIG. 4, in the threshold condition file, an initial value of a threshold used at the time of detecting a scene switching point is stored in association with a program genre. For genres that are expected to change scenes frequently, such as sports,
A low initial value is associated with a genre that is expected to have a long scene switching time interval such as “conversation”. That is, the CPU 102 functions as a range setting unit. Also, as shown in FIG. 5, the reservation information includes a broadcasting station,
The information includes a start time, an end time, an initial value, whether a scene can be detected, and a title.

On the other hand, in the case of recording reservation by manual setting, C
The PU 102 provides a user interface for making a recording reservation by manual setting. The reservation content input using this user interface and the hard disk 10
The reservation information is generated on the basis of the threshold condition file on No. 5, stored in the reservation area on the bird disk 105, and the disclosure date and time in the reservation information is set in the timer 107.

(3) Broadcast Reception Function Next, the broadcast reception function will be described. When receiving a broadcast, the CPU 102 controls the video input unit 108 to receive a broadcast station to be received. As a result, the video input unit 108 receives the broadcast of the broadcast station to be received, converts the received video into a video signal in the MPEG2 format, and outputs the video signal to the bus 101. Further, when the reception of the broadcast is stopped, the CPU 102 controls the video input unit 108 to stop the reception of the broadcast.

(4) Scheduled Recording Function Next, the scheduled recording function will be described. When the reservation information exists in the reservation area on the hard disk 105 and the current time matches the start time in any of the reservation information, the CPU 102 controls the video input unit 108 to receive the broadcast of the broadcasting station in the reservation information. (Broadcast reception function), and a new scene switching point list is generated on the RAM 104. Further, the CPU 102 performs a writing process for controlling each unit so that the video data in the MPEG2 format output from the video input unit 108 is written to the hard disk 105, a scene switching point list creation process described later, and a current time monitoring process. And run.

When the current time coincides with the end date and time in the reservation information, the CPU 102 terminates the writing process and the scene switching point list creation process, and associates the reservation information with the video data written in the hard disk 105 and makes the unique information. Of the scene switching point list created on the RAM 104 by the scene switching point list creation process, as identification data (for example, the file name of the image data file and the creation of the image data file). (Date and time) is stored in the hard disk 105 as a file having a file name.

Here, the scene switching point list creation processing will be described. The video data taken in from the bus 101 to the CPU 102 in the scene switching point list creation processing is, specifically, MPEG2 format compressed data. M
As shown in FIG. 6, the data structure of PEG2 has a six-layer structure of a sequence layer, a GOP (Group Of Pictures) layer, a picture layer, a slice layer, a macroblock layer, and a block layer. Data (eg GO
P) includes at least one lower layer data (for example, a picture). The GOP is a unit of random access, and the GOP layer includes a time code indicating a time from the beginning of the sequence. In the picture layer, a picture number (Temporal Reference), which is a serial number assigned to a picture in the GOP, and I, B, P
And a picture type indicating the distinction between the D picture and the DCT (discrete cosine transform) for the block in the block layer
A variable-length code indicating a coefficient (hereinafter, a coded DCT coefficient) is included.

FIG. 7 is a conceptual diagram showing an example of the structure of the scene switching point list. As shown in FIG. 7, the scene switching point list created by the scene switching point list creation processing is a set of a time code and a picture number. Are stored in order. To create this scene change point list, C
As illustrated in FIG. 8, the PU 102 first sets the value of the flag indicating whether or not processing is being performed on the I picture to a value (for example, 0) indicating that processing is not being performed on the I picture, and is set for the video to be recorded. The set initial value is set as a threshold value in a predetermined register, and a reference value used as a comparison target when a scene change point is detected is initialized.
The process of loading data is started at the timing when the data on the first data is updated (step SB1). Note that the leading I
To ensure that the picture is always detected as a scene change point,
The reference value is initialized to a value far from the assumed comparison target.

Further, the CPU 102 sequentially cuts out new data from the fetched data in accordance with the data structure of MPEG2 (step SB2), and processes based on the cut out new data (steps SB3 to SB1).
Step 9) is repeated. Hereinafter, processing based on the extracted new data will be specifically described.

When the new data is a time code, the CPU
102 overwrites the time code in a predetermined register and makes it available as a time code for indicating a scene switching point (steps SB3 and SB4).

If the new data is a picture number, the CPU
102 overwrites the picture number in a predetermined register and makes it available as a picture number for indicating a scene switching point (steps SB5 and SB6). These time code and picture number are used when detecting a scene switching point.

If the new data is a picture type and the picture type is not a picture type indicating an I picture, the CPU 102 sets the value of the flag to a value indicating that processing is not being performed on the I picture (step S).
B7 to SB9). When the new data is a picture type and the picture type is a picture type indicating an I picture, the CPU 102 sets the value of the flag to a value (for example, 1) indicating that processing is being performed on the I picture. Finally, the cumulative value which is the total value of coefficient values (described later) for all blocks in the same picture is set to 0 (steps SB7, SB8 and SB1).
0).

If the new data is a coded DCT coefficient and the processing for the I picture is in progress, the CPU 1
02 decodes the coded DCT coefficient to obtain a DCT coefficient, determines a coefficient value from the DCT coefficient, and adds the coefficient value to the accumulated value (steps SB11 to SB15). Various methods are conceivable for determining the coefficient value. In the present embodiment, the coefficient values of the block are obtained by weighting and adding the values of the DCT coefficients in the block. This weighting is performed so that the specific gravity of the DCT coefficient (such as a low-frequency term of a DC component or an AC component) having a large effect on human vision becomes large.

When the new data is not any of the time code, picture type, picture number and coded DCT coefficient, or when the coded DCT coefficient is for a block in a picture other than the I picture, no processing is performed. Not performed (steps SB11 and SB12).

For all blocks in the same I picture,
The value of the flag is a value indicating that processing is being performed on the I picture. Therefore, the CPU 102 performs a process of adding the coefficient value for each block to the accumulated value for all blocks in the same I picture. Therefore, the final cumulative value is the sum of the coefficient values for all blocks in the same I picture (step SB15).

When the final accumulated value is obtained, the CPU
102 calculates the absolute value of the difference between the reference value and the accumulated value,
The accumulated value is set as a reference value (step SB16).
That is, the CPU 102 functions as a difference calculation unit.
Further, when the absolute value of the calculated difference exceeds the threshold value, the CPU 102 adds the time code and the picture number stored in the predetermined register to the scene switching point list on the RAM 104 and sets the threshold value as the recording target. (Step SB1)
7 and SB18). That is, the CPU 102 functions as a specifying unit and a detecting unit.

For example, when the coefficient value (total value) for an I picture in an MPEG2 bit stream changes as shown in FIG. 9, the absolute value of the difference between the coefficient value and the immediately preceding I picture is as shown in FIG. Change. In FIG.
In the I pictures, the absolute value of the difference exceeds the threshold, and at the time of processing these six I pictures, C
The time code and picture number stored in the PU 102 are added to the scene switching point list. That is, the CPU 102 sets D
An I picture (and an I picture at the head of the bit stream) in which the CT coefficient is largely changed is specified, and the appearance point of the I picture is detected as a scene switching point.

Conversely, if the calculated absolute value of the difference is equal to or smaller than the threshold, the CPU 102 subtracts a predetermined number from the threshold to obtain a new threshold (step SB17 and step S17).
B19). That is, as shown in FIG. 10, the threshold value gradually decreases each time an I picture not detected as a scene switching point appears, and is initialized each time an I picture detected as a scene switching point appears. That is, the CPU 102 functions as a range changing unit.

(5) Scene Presentation Function Next, the scene presentation function will be described. When a request to present a scene is made, the CPU 102 acquires identification information from the video data file specified by the request, and stores a scene switching point list corresponding to the identification information on the hard disk 1.
05, the image data corresponding to the time code and the picture number stored in the scene switching point list is read from the video data file, and the images represented by these image data are reduced and arranged in the appearance order. Generate data representing a selection menu screen (see FIG. 11),
This data is written to the frame memories 109 and 111 via the bus 101. That is, the CPU 102 functions as a presentation unit. FIG. 11 shows an example of a scene selection menu screen.

(6) Reproduction Function Next, the reproduction function will be described. When there is a playback request,
The CPU 102 provides a user interface for selecting a video data file to be reproduced from a recorded video data file. Specifically, the CPU 102
Refers to the reservation information in all the video data files stored in the hard disk 105, generates data representing a recorded program selection menu screen (see FIG. 12) based on the reservation information, and transmits this data via the bus 101. To write to the frame memories 109 and 111. Furthermore, CPU1
02 selects a video data file based on the user interface and a signal input from the operation unit 106,
A scene is presented for the video data file (scene presentation function). FIG. 12 is a diagram showing an example of the recorded program selection menu screen. In this figure, the recording start date and time, time, and title are displayed for each video data file. Note that “time” in FIG. 12 is based on the start date and time and the end date and time in the reservation information.
2 and indicates the length of the video in the video data file.

Further, the CPU 102 selects one reduced image on the scene selection menu screen according to the user's instruction after visually recognizing the scene selection menu screen, and from the position indicated by the time code and the picture number corresponding to the reduced image, The video data in the data file is decoded and reproduced, and the generated video data is written to the frame memories 109 and 111 via the bus 101 for each frame. Note that C
The PU 102 ends the reproduction when the video data is completely reproduced.

C: Operation Next, the operation of the video recording apparatus having the above configuration will be described. (1) EPG Reception Operation First, the EPG reception operation will be described. When the video input unit 108 is ready to receive a broadcast by a user's operation, the video input unit 108
Also, EPG of satellite television broadcasting can be received. In such a situation, when the EPG of the terrestrial television broadcast or the EPG of the satellite television broadcast is received by the video input unit 108, the EPG file on the hard disk 105 is updated based on the EPG.

(2) Recording Reservation Operation Next, a recording reservation operation using the EPG and a manual recording reservation operation will be described with reference to FIG. However, in any operation, the initial state of the CPU 102 is assumed to be the operating state.

Recording Reservation Operation Using EPG In the recording reservation operation using the EPG, the operation unit 106
When a signal instructing the start of recording reservation by G is supplied via the bus 101, the CPU 102
The program information is read from the EPG file on the computer program 05, and a user interface corresponding to the read program information is provided (step SA1). Specifically, the CPU 102
By generating image data corresponding to the program information in the EPG and supplying the generated image data to the frame memory 111, the EPG reservation screen illustrated in FIG. 3 is displayed on the internal display 113, and the user who visually recognizes the EPG reservation screen is displayed. Select program information according to the operation of the operation unit 106 by the
This selection is reflected on the PG reservation screen. For example, in FIG.
On the PG reservation screen, it is shown that the program indicated by oblique lines is selected. When a signal for instructing scene detection at the time of recording is supplied from the operation unit 106 when the user interface is provided, the CPU 102 sets a scene detection enable / disable flag indicating whether or not scene detection is possible, and displays the EPG reservation screen on the EPG reservation screen. Reflect this set.
For example, on the EPG reservation screen in FIG. 3, a check box indicating whether or not scene detection is possible is checked (steps SA1 to SA3).

Further, when a signal indicating an instruction to determine the contents of reservation is supplied from the operation unit 106 at the time of providing the user interface, the CPU 102 sets a threshold condition corresponding to the genre in the selected program information to the hard disk 105.
The reservation information (see FIG. 5) is read out from the above threshold condition file (see FIG. 4), reservation information (see FIG. 5) is generated based on the threshold condition, the selected program information, and the scene detection enable / disable flag. The start date and time in the reservation information are set for the timer 107 and the timer 107 is set to a predetermined time before the start date and time.
(Step S)
A3 to SA4).

In the recording reservation operation by manual setting, in the recording reservation operation by manual setting, a signal instructing the start of the recording reservation by manual setting from the operation unit 106 is transmitted to the bus 10.
1, the CPU 102 provides a user interface for manual setting (step SA1).
This user interface is similar to the user interface for recording reservation in a general video recording apparatus except that the setting items include an initial value and whether or not scene detection is possible. Detailed description is omitted. The reservation information determined by the reservation operation using this user interface is stored in a reservation area on the hard disk 105,
In 07, the start date and time in the reservation information is set (steps SA3 to SA4).

(3) Scheduled Recording Operation Next, a scheduled recording operation for recording according to the schedule information will be described mainly with reference to FIG. However, the CPU 10
It is assumed that the initial state of No. 2 is an interrupt waiting state. When the current time is a predetermined time before the start date and time in any of the reservation information stored in the reservation area of the hard disk 105, an interrupt signal is output from the timer 107, and the CPU 102 that has received the interrupt signal enters an operating state (step S).
D1). The CPU 102 in the operating state is the timer 107
, The current time is obtained (step SD2).

When the CPU 102 is in the operating state, R
If the start date and time of any of the reservation information stored in the reservation area on the AM 104 matches the current time (step SD)
3), the broadcast of the broadcasting station in the reservation information is
8 and a new scene change point list is generated on the RAM 104 (step SD4).
Here, the CPU 102 transmits the MPEG2 format video data output from the video input unit 108 to the hard disk 10.
5 and the above-described scene switching point list creation process (step S).
D5).

In the scene change point list creation processing, first,
The appearance point of the first I picture of the video is unconditionally detected as a scene switching point. Subsequently, in the comparison of the total value of the DCT coefficient values, the appearance point of the I picture in which the absolute value of the difference from the immediately preceding I picture is larger than the threshold value is detected as the scene switching point. The initial value of the threshold is a value set in the reservation information according to the program to be recorded, and is a value according to the genre of the program. In addition, the threshold value gradually decreases every time an I-picture that is not detected as a scene switching point appears, and returns to the initial value at the time of scene detection. As a result of such processing, as shown in FIG. 10, a scene switching point list is created in which a section in which a scene switching point does not exist does not continue to some extent or more.

If the current time coincides with the end date and time in the reservation information during the execution of the writing process and the scene switching point list creation process, the writing process and the scene switching point list creation process are terminated. The included video data file is stored on the hard disk 105, and the scene switching point list created on the RAM 104 is stored on the hard disk 105 in association with the video data file (step SD6). At this time, the reservation information is deleted from the hard disk 105.

(4) Reproduction Operation Next, the reproduction operation will be described with reference to FIG. At the time of reproduction, first, a user interface (see FIG. 12) for selecting a video data file to be reproduced from a recorded video data file is provided (step SE).
1). When the user selects a video data file using this user interface, a user interface (see FIG. 11) for selecting a reproduction start scene of the video data file is provided (step SE2).

When the user selects one reduced image using this user interface, the video in the video data file is decoded and reproduced from the position represented by the time code and picture number corresponding to the reduced image, and It is displayed on the display 113 and output from the analog output unit 110 (step SE3). When the video data has been reproduced to the end, the reproduction operation ends.

D: Supplement As described above, according to the present embodiment, the initial value of the threshold used for detecting the scene switching point is set according to the genre of the program to be recorded. Compared to the case where the initial value is a fixed value, the interval between detected scene switching points can be optimized. In addition, the threshold value gradually decreases while the I-pictures that do not become scene switching points continue in the scene switching point list creation processing, and are initialized when an I-picture that becomes a scene switching point appears. It is guaranteed that the section in which no point is detected does not continue for a certain length. That is, according to the present embodiment, it is possible to prevent the interval between the detected scene switching points from expanding to a certain extent. In the present embodiment, a process of changing the threshold for each genre of the program;
Although an example in which the process of changing the threshold value is performed in parallel with the creation of the scene switching point list has been described, it is needless to say that only one of the processes may be performed.

[Second Embodiment] Next, a video recording apparatus according to a second embodiment of the present invention will be described. However, this video recording apparatus is different from the video recording apparatus according to the first embodiment only in the scene switching point list creation processing and various settings associated with this processing, and the description of other parts will be omitted.

A: Difference from the First Embodiment FIG. 16 is a flowchart showing the flow of the former stage of the scene switching point list creation processing in the second embodiment of the present invention. The same reference numerals are given. The scene switching point list creation processing shown in this figure differs from the processing shown in FIG. 8 in that a threshold is not set (step SF1), and the difference, the current time code, and the picture number are saved after the difference is calculated. (Step SF2). As is clear from FIG. 16, in the first stage of the scene switching point list creation processing in the second embodiment, a time code, a picture number, and a difference are saved for each I picture. These save destinations are RAM
104. Further, since no threshold is set, the “genre” in the threshold condition file in FIG. 4 and the program information in FIG. 2 is not required at the time of recording reservation.

Next, the latter stage of the scene switching point list creation process in the second embodiment will be described. This processing is performed when the scene switching point list creation processing is stopped. First, the number of scene switching points to be detected is determined according to the length of the recorded video, and then the information saved in the RAM 104 is determined. , The time code and the picture number are extracted in descending order of the difference, and are written in the scene switching point list in the order according to the time code and the picture number.
However, the number of pairs of the extracted time code and picture number is a number determined according to the length of the video. Specifically, for example, when the number determined according to the length of the image is 5, as shown in FIG. 17, the five points pointed above the broken line are detected as the scene switching points. Become. Note that since the subject of the above processing is the CPU 102, the CPU 102 functions as a number setting unit, a batch specifying unit, and a batch detection unit.

B: Supplement As described above, according to the present embodiment, the number of scene switching points corresponding to the length of the recorded video is always detected. Therefore, it is possible to avoid a situation that is likely to occur at the time of detecting a scene switching point for an image having almost no scene switching, and that a scene switching point that is too small compared to the length of a recorded image can be detected. As a result, it is possible to expect an appropriate interval between the detected scene switching points.

In the present embodiment, the scene switching points are extracted in the descending order of the difference. However, this is merely an example. For example, the scene switching points are extracted so that at least one scene switching point exists within a predetermined time. Switching points may be extracted, or scene switching points may be extracted so as to form a uniform distribution. Of course, these may be combined. Further, a user may be able to set a rule for extracting a scene switching point.

[Supplement to Entire Embodiment] According to each of the above-described embodiments, it is possible to perform a process of detecting a scene switching point without decoding an MPEG2 bit stream.
In addition, since the only picture to be processed when creating the scene switching point list is the I picture, and only the sum of the coefficient values based on the DCT coefficients is to be compared, the MPEG2 bit stream is decoded. As compared with the case where the scene switching point is detected after that, the load on the process of detecting the scene switching point can be significantly reduced.

In each of the above embodiments, the video input unit 10
8 is MPEG2,
1, MPEG4, ITU (International Telecommunication Union) -T. 261 Recommendation, Motion JPEG (J
oint Photographic Coding Experts)) and other formats such as uncompressed. In either case, the threshold value changes for each data unit that can be a scene switching point. Also, an example has been shown in which the threshold value is gradually reduced every time an I picture that does not become a scene switching point appears. However, this is only an example. For example, the threshold value is not increased until an I picture that does not become a scene switching point appears continuously a predetermined number of times. You may make it reduce.

Also, an example has been described in which only a broadcast program is recorded.
It is easy to change to record video stored in an external storage medium such as a ROM. Also, an example has been described in which a scene switching point list is created at the time of recording. However, a scene switching point list may be created after recording.
Further, when there is an external device using the scene switching point list (for example, a remote controller having a liquid crystal panel capable of displaying a scene selection menu screen), the above-described operation is performed so as to output the scene switching point list to the external device. Each embodiment may be modified.

[0069]

As described above, according to the present invention,
Irrespective of the content of the video, it is possible to correct some of the scene switching points and the bias on the time axis, and as a result, to make the time interval between each other more appropriate for any video. A switching point is detected. Therefore, by using the scene switching point detected according to the present invention, the convenience for the user can be surely improved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a video recording device according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram showing items in program information used in the video recording device.

FIG. 3 is a diagram showing an example of an EPG reservation screen displayed by the video recording device.

FIG. 4 is a conceptual diagram showing an example of the structure of a threshold condition file stored on a hard disk 105 of the video recording apparatus.

FIG. 5 is a conceptual diagram showing an example of reservation information used in the video recording device.

FIG. 6 shows MPEG used in the video recording apparatus.
FIG. 3 is a conceptual diagram showing a structure of two types of compressed data.

FIG. 7 is a conceptual diagram showing an example of the structure of a scene switching point list created by the video recording device.

FIG. 8 is a flowchart showing a flow of a scene switching point list creation process by the video recording device.

FIG. 9 is a diagram illustrating an example of a temporal change of a coefficient value (total value) for an I picture in an MPEG2 bit stream.

10 is a diagram showing an example of a temporal change in the absolute value of a difference between a coefficient value and an immediately preceding I picture in the bit stream shown in FIG. 9 and an example of detecting a scene switching point by the video recording apparatus according to the first embodiment; It is.

FIG. 11 is a diagram showing an example of a scene selection menu screen displayed by the video recording device.

FIG. 12 is a diagram showing an example of a recorded program selection menu screen displayed by the video recording device.

FIG. 13 is a flowchart showing a flow of a recording reservation operation by the video recording device.

FIG. 14 is a flowchart showing the flow of a scheduled recording operation by the video recording device.

FIG. 15 is a flowchart showing a flow of a reproducing operation by the video recording device.

FIG. 16 is a flowchart illustrating a flow of a former stage of a scene switching point list creation process by the video recording device according to the second embodiment of the present invention.

FIG. 17 is a diagram showing an example of a temporal change in the absolute value of a difference between a coefficient value and an immediately preceding I picture in the bit stream shown in FIG. 9 and an example of detecting a scene switching point by the video recording apparatus according to the second embodiment. It is.

[Explanation of symbols]

101: bus, 102: CPU, 103: RO
M, 104: RAM, 105: Hard disk, 1
06 Operation unit 107 Timer 108 Image input unit 109 111 Frame memory 110
Analog output unit, 112 ... Display control unit, 11
3. Internal display.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H04N 5/765 H04N 5/781 510L 5/781 5/92 H 5/92 7/08 A 7/025 7/03 7 / 035 F term (reference) 5C025 AA28 BA25 BA27 BA28 BA30 CA09 CB08 CB09 DA01 DA04 DA05 DA10 5C052 AA01 AA17 AB03 AB04 AC08 CC11 DD04 DD10 EE02 EE03 5C053 FA23 FA27 GB09 GB38 HA30 JA21 KA04 KA24 LA07 5AC03 AB EB32 EB33 5D077 AA22 AA30 BA11 CB01 DC22 DF05 HC27

Claims (16)

[Claims] 1. A scene switching point detecting method for detecting a scene switching point from a video composed of a plurality of images continuous on a time axis, wherein a time interval between the switching point candidates is an appropriate interval. Extracting the switching point as described above. 2. A scene switching point detection method for detecting a scene switching point from a video composed of a plurality of images continuous on a time axis, wherein: a content obtaining step of obtaining information indicating the content of the video; A specifying step of specifying a target image whose difference from the immediately preceding target image is out of a range based on the information obtained in the content obtaining step, among the target images that can be the switching point in the video; and Detecting a time point according to the target image selected as the switching point as the switching point. 3. A scene switching point detection method for detecting a scene switching point from a video composed of a plurality of images continuous on a time axis, wherein a target image that can be the switching point in the video is a target image immediately before the target image. A difference specifying step of obtaining a difference between the target image, a batch specifying step of specifying a preset number of target images in descending order of the difference obtained in the difference specifying step, and a target image specified in the specifying step. A batch detection step of detecting a corresponding time point as the switching point. 4. A scene switching point detection method for sequentially detecting a scene switching point along a time axis from a video composed of a plurality of images continuous on a time axis, wherein the switching point in the video can be the switching point. When the difference between the image and the immediately preceding target image is within the range, the range is narrowed, and when the difference is outside the range, a time point according to the target image is detected as the switching point and the range is expanded. Scene switching point detection method. 5. A scene switching point presentation device for detecting and presenting a scene switching point from a video composed of a plurality of images continuous on a time axis, wherein a range setting unit for setting information representing a range, An input unit that inputs a video, a difference calculation unit that obtains a difference between a target image that can be the switching point in the video input by the input unit and a previous target image, and the difference calculation unit that obtains the difference. A specifying unit that specifies a target image outside the range according to the information set by the range setting unit, and a detecting unit that detects a time point according to the target image specified by the specifying unit as the switching point, A presentation unit that presents the switching point detected by the detection unit. 6. A scene change point presentation device for detecting and presenting scene change points from a video composed of a plurality of images continuous on a time axis, wherein information indicating the number of the change points to be detected is provided. A number setting unit to be set; an input unit to input the video; a difference calculation unit to calculate a difference between a target image that can be the switching point in the video input by the input unit and a previous target image; A collective specifying unit that specifies the number of target images according to the information set by the number setting unit in the descending order of the difference obtained by the difference calculating unit, and a time corresponding to the target image specified by the collective specifying unit. A scene switching point presentation device, comprising: a batch detection unit that detects the switching point; and a presentation unit that presents the switching point detected by the batch detection unit. 7. A scene switching point presentation device for detecting and presenting a scene switching point from a video composed of a plurality of images continuous on a time axis, wherein: an input unit for inputting the video; A difference calculation unit that obtains a difference between the target image that can be the switching point and the immediately preceding target image; and a specifying unit that specifies a target image in which the difference obtained by the difference calculation unit is out of a preset range. A detecting unit that detects a point in time according to the target image specified by the specifying unit as the switching point; a presenting unit that presents the switching point detected by the detecting unit; and the difference obtained by the difference calculating unit. A range changing unit that narrows the range when the value is within the range, and expands the range when the value is outside the range. 8. A scene switching point detecting device for detecting a scene switching point from a video composed of a plurality of images continuous on a time axis, a range setting unit for setting information representing a range, and inputting the video. An input unit, a difference calculation unit that obtains a difference between a target image that can be the switching point in the video input by the input unit and an immediately previous target image, and the difference obtained by the difference calculation unit is A specifying unit that specifies a target image outside the range according to the information set by the range setting unit; a detecting unit that detects a point in time according to the target image specified by the specifying unit as the switching point; An output unit for outputting information indicating the switching point detected by the above-described method. 9. A scene change point detecting device for detecting a scene change point from a video composed of a plurality of images continuous on a time axis, wherein a number indicating information indicating the number of the change points to be detected is set. A setting unit, an input unit that inputs the video, a difference calculation unit that calculates a difference between a target image that can be the switching point in the video input by the input unit and a previous target image, and the difference calculation unit. A batch specifying unit that specifies the number of target images according to the information set by the number setting unit in the descending order of the difference obtained by: A scene switching point detection device, comprising: a batch detection unit that detects the change in the scene; and an output unit that outputs information indicating the switching point detected by the batch detection unit. 10. A scene switching point detection device for detecting a scene switching point from a video composed of a plurality of images continuous on a time axis, an input unit for inputting the video, and the switching point in the video. A difference calculation unit that obtains a difference from the immediately preceding target image with respect to a target image that can be: a specifying unit that specifies a target image in which the difference obtained by the difference calculation unit is outside a preset range; A detecting unit that detects a point in time according to the specified target image as the switching point; an output unit that outputs information indicating the switching point detected by the detecting unit; and the difference calculated by the difference calculating unit. A range changing unit that narrows the range when the value is within the range, and expands the range when the value is outside the range. 11. A video reproducing apparatus which detects and presents a scene switching point from a video composed of a plurality of images continuous on a time axis and starts reproduction of a video from a switching point designated by a user. An instruction input unit for inputting a user instruction; a video storage unit storing the video; a range setting unit for setting information representing a range; A difference calculation unit that obtains a difference from an image, a specifying unit that specifies a target image outside the range according to the information set by the range setting unit, wherein the difference obtained by the difference calculation unit; A detection unit that detects a time point according to the specified target image as the switching point; a presentation unit that presents the switching point detected by the detection unit; and a presentation content of the presentation unit and the input unit. Video reproducing apparatus according to claim from switching point in response to the force has been instructed and that it comprises a reproduction unit for reproducing the video. 12. A video reproducing apparatus which detects and presents a scene switching point from a video composed of a plurality of images continuous on a time axis and starts reproduction of the video from a switching point designated by a user. An instruction input unit for inputting a user instruction; an image storage unit storing the image; a number setting unit for setting information indicating the number of the switching points to be detected; and the switching point in the image A difference calculation unit for calculating a difference between the target image that can be the target image and the immediately preceding target image; and specifying a number of target images according to the information set by the number setting unit in descending order of the difference obtained by the difference calculation unit. A collective specifying unit; a collective detecting unit that detects a point in time according to the target image specified by the collective specifying unit as the switching point; and a presentation that presents the switching point detected by the collective detecting unit. When the video reproducing apparatus characterized by comprising a reproducing unit for reproducing the video from the switching point in response to an instruction and input by the input unit and presenting the contents of the presentation unit. 13. A video reproducing apparatus which detects and presents a scene switching point from a video composed of a plurality of images continuous on a time axis and starts reproduction of the video from a switching point designated by a user. An instruction input unit for inputting a user's instruction, a video storage unit storing the video, a difference calculation unit that calculates a difference between a target image that can be the switching point in the video and a previous target image, A specifying unit that specifies a target image outside the range in which the difference obtained by the difference calculation unit is set in advance, and a detection unit that detects a time point according to the target image specified by the specifying unit as the switching point, When the difference calculated by the difference calculation unit is within the range, the range is narrowed, and when the difference is outside the range, a range change unit that expands the range, and a switching point detected by the detection unit is Image reproducing apparatus for a Shimesuru presentation unit, characterized by comprising a reproducing unit for reproducing the video from the switching point in response to an instruction and input by the input unit and presenting the contents of the presentation unit. 14. A video recording apparatus for detecting a scene switching point from a video composed of a plurality of images continuous on a time axis and recording information indicating the switching point in association with the video. An input unit, a video storage unit that stores a video input from the input unit, a range setting unit that sets information indicating a range, and a target image immediately before the target image that can be the switching point in the video. A difference calculation unit that obtains a difference between: a difference unit that is determined by the difference calculation unit; a specifying unit that specifies a target image outside a range corresponding to information set by the range setting unit; And a switching point storage unit that stores information representing the switching point detected by the detection unit in association with the video data. Video recording apparatus according to claim Rukoto. 15. A video recording apparatus for detecting a scene switching point from a video composed of a plurality of images continuous on a time axis and recording information indicating the switching point in association with the video. An input unit, an image storage unit that stores an image input from the input unit, a number setting unit that sets information indicating the number of the switching points to be detected, and a switching point in the image. A difference calculation unit that calculates a difference between the target image and the immediately preceding target image; and a collective specification that specifies a number of target images according to the information set by the number setting unit in descending order of the difference calculated by the difference calculation unit. A batch detection unit that detects a point in time according to the target image specified by the batch identification unit as the switching point; and information indicating the switching point detected by the batch detection unit to the video data. Image recording apparatus characterized by comprising a switching point storage unit which stores in association with the data. 16. A video recording apparatus for detecting a scene switching point from a video composed of a plurality of images continuous on a time axis and recording information indicating the switching point in association with the video, An input unit, a video storage unit that stores a video input from the input unit, a difference calculation unit that obtains a difference between a target image that can be the switching point in the video and a previous target image, and the difference calculation. A specifying unit that specifies a target image in which the difference obtained by the unit is out of a preset range; a detecting unit that detects a time point according to the target image specified by the specifying unit as the switching point; A switching point storage unit for storing information representing the switching point detected by the unit in association with the video data; and narrowing the range when the difference obtained by the difference calculation unit is within the range. The video recording apparatus characterized by comprising a range change unit to expand the range in the case of out of the range.