JP2001061131A - Image recorder, method and computer-readable storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a scene from not being reproduced through the use of a TOC at reproduction on the occurrence of an abnormal recording end, such as power failure half-way through the scene. SOLUTION: A buffer 115 stores image data that are variable-length-coded. A rate control circuit 116 reads buffer at a rate higher than an input rate and a recording medium 118 records the read image data via a recording processing circuit 117. Since the recording rate is higher than the input rate, an unrecorded period of image data is generated. When a change in an image pattern is detected, a TOC control circuit 122 records TOC for the unrecorded period. Thus, even if there is abnormal end of recording, reproduction is attained on the basis of the TOC until the time of the final image pattern change of the scene at reproduction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image recording apparatus and method suitable for use in performing digital moving image recording on a recording medium such as a disk medium, and a computer-readable storage medium used therein. .

[0002]

2. Description of the Related Art In a conventional moving picture recording apparatus of this type, TOC (Tab) is used as index information indicating the position of a scene from the start of recording to the stop of recording on a disk.
Information called 1eOf Contents) is recorded in a predetermined TOC recording area of the disc.
At the time of reproduction, a desired scene is reproduced based on the TOC, so the TOC is very important information.

[0003] Recording of such a TOC on a disk is as follows.
Conventionally, the recording is performed under the control of the user after the recording of the scene is completed.

[0004]

Conventionally, the recording of the TOC is performed under the control of the user, and in some cases, the TOC is not recorded for a long time. Therefore, if the recording of the scene is not completed normally for some reason, for example, when the power is turned off during the recording of the scene, there is a problem that the reproduction cannot be performed because there is no TOC of the scene at the time of reproduction.

[0005] The present invention has been made to solve the above-mentioned problem, and even if the recording is not completed normally,
The purpose is to record the data so that it can be played back normally halfway.

[0006]

In order to achieve the above object, in an image recording apparatus according to the present invention, a detecting means for detecting a change in screen of input image data, and recording the image data on a recording medium. Recording processing control means for recording index information on the image data on the recording medium in response to detection of a screen change by the detection means.

Further, in the image recording method according to the present invention, a procedure for detecting a screen change of the input image data, a procedure for temporarily storing the image data, and a procedure for storing the stored image data in the input Reading the image data at a higher rate than the rate of the image data to be read, recording the read image data on a recording medium, and index information relating to the image data in response to the detection of the screen change. Recording the data on the recording medium during the non-recording period of the data.

[0008] In the storage medium according to the present invention,
A process of detecting a screen change of input image data, a process of temporarily storing the image data, and a process of reading the stored image data at a rate higher than the rate of the input image data, A process of recording the read image data on a recording medium, and a process of recording index information on the image data on the recording medium in a non-recording period of the image data in response to the detection of the screen change; Is stored.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an image recording apparatus according to an embodiment of the present invention. Reference numeral 104 denotes an image memory for storing an image signal input from a camera or the like, 105 denotes a switch, 106 denotes an adder, 107 denotes a DCT (orthogonal transform) circuit, 108 denotes a quantization circuit, 109 denotes a variable-length coding circuit, and 110 denotes a variable-length coding circuit. Inverse quantization circuit, 111: IDCT (inverse orthogonal transform) circuit, 112: adder, 113: motion compensation circuit, 114: switch, 115: buffer, 116: rate control circuit, 117: recording processing circuit, 118: disk, etc. Reference numeral 120 denotes a screen change detection circuit, 121 denotes a TOC memory for storing TOC information, and 122 denotes a TOC control circuit.

Next, the operation will be described. The image signal is input to the image memory 104 in frame units. The image memory 104 has a capacity capable of storing a plurality of frames, and outputs the input image signal by changing the order of the frames.

Next, the screen rearrangement will be described with reference to FIG. In FIG. 2, the image signals input in units of one frame such as a first frame, a second frame, a third frame,... Are rearranged in a frame order, and are arranged in a third frame, a first frame, a second frame,. Is output.

The screen rearrangement is necessary when an image signal is intra-coded and inter-coded as shown in FIG. Intra coding is coding using only data in a frame, and is coding for generating the I picture in FIG. Also, the inter coding is
The encoding is performed including the inter-frame prediction, and is the encoding for generating the P picture and the B picture in FIG.

Next, the intra coding and the inter coding will be described separately. When performing intra coding, the switch 105 is connected to the A side. The image data output from the image memory 104 is input to the DCT circuit 107 via the switch 105 and is orthogonally transformed. The orthogonally transformed image data is quantized by the quantization circuit 108 according to the quantization coefficient determined by the rate control circuit 116. The quantized image data is input to the inverse quantization circuit 110 and the variable length coding circuit 109. The image memory 10
4 is output to the motion compensation prediction circuit 113.
And to the screen change detection circuit 120.

The quantized data is supplied to an inverse quantization circuit 1
The data is inversely quantized at 10 and subjected to IDCT at the IDCT circuit 111. The IDCT-processed image data is input to the motion compensation circuit 113 with the switch 114 turned off. The motion compensation prediction circuit 113 generates and outputs a predicted image for the next inter encoding.

The quantized data is input to a variable-length encoding circuit 109, is subjected to variable-length encoding, and is input to a buffer 115. When the image data in the buffer 115 reaches a certain data amount, it is recorded on the recording medium 118 via the recording processing circuit 117 at a rate higher than the input data rate.

In the case of inter coding, the switch 10
5 is connected to the B side. The image data output from the image memory 104 is subtracted by the subtractor 106 from the predicted image from the motion compensation prediction circuit 113 via the switch 105. The subtractor 106 is provided to reduce the redundancy in the time axis direction.

The image data with the reduced redundancy in the time axis direction is input to the DCT circuit 107 and subjected to orthogonal transformation. The orthogonally transformed image data is supplied to a rate control circuit 11.
6 according to the quantization coefficient determined by
Is quantized by The quantized image data is input to the inverse quantization circuit 110 and the variable length coding circuit 109. The image data output from the image memory 104 is also input to the motion compensation prediction circuit 113 and the screen change detection circuit 120.

The quantized data is supplied to an inverse quantization circuit 1
The data is inversely quantized at 10 and subjected to IDCT at the IDCT circuit 111. The IDCT-processed image data is input to the motion compensation circuit 113 with the switch 114 turned off. Also,
The switch 114 is turned on, and the adder 112 adds the predicted image from the motion compensation prediction circuit 113 to the decoded image. This decoded image is input to the motion compensation prediction circuit 113 for the next image encoding. Motion compensation prediction circuit 113
Outputs a predicted image and a motion vector. The motion vector is input to the variable length coding circuit 109. Further, a predicted image is output for the next inter-coding.

The quantized data is input to a variable-length coding circuit 109, is subjected to variable-length coding, and is input to a buffer 115. When the image data in the buffer 115 reaches a certain data amount, it is recorded on the recording medium 118 via the recording processing circuit 117 at a rate higher than the input data rate.

Next, recording of TOC as index information in the present embodiment will be described. The screen change detection circuit 120 reads out image data of a plurality of frames stored in the image memory 104, and calculates a difference value A A of the luminance information between frames A = {| Frame1 (Y)-(Frame2 (Y) |}. (1) is calculated, and when the difference value A is larger than a certain threshold value TH, that is, when A> TH, a screen change is detected.

Based on this detection, the screen change circuit 120
Outputs a control signal to the TOC control circuit 122,
When the control circuit 122 detects this control signal, the control circuit 122 controls the TOC memory 121 to record the TOC in the TOC recording area of the recording medium 118 via the recording processing circuit 117 using the period when the image data is not recorded. I do.

The TOC control circuit 122 controls the TOC memory 121 even when recording is stopped or when recording is temporarily stopped, and records the TOC on the recording medium 118 using a period in which no image data is recorded.

FIG. 4 is a diagram for explaining the TOC recording timing. The symbol “★” in the figure indicates the screen change detection circuit 12.
0 indicates a point in time when a large screen change is detected. FIG.
In the scene 1, TOC is set to TO at the timing of the screen change detection (a), the pause (b), and the recording stop (c).
Record in the C recording area.

As described above, the image data is stored in the buffer 1
15 and is recorded on the recording medium 118, and can be recorded at a higher rate than the data rate of the input image data. Therefore, a non-recording period occurs during the recording of image data (the hatched portion in FIG. 4B). Therefore, even during image data recording, the head can be sought to the TOC recording area during the non-recording period to record the TOC.

In the scene 1, since the recording is stopped normally, all the recorded data can be normally reproduced.

Next, in scene 2, screen change detection (d,
The TOC is recorded in the TOC recording area at the timing of e). In this example, the power is shut off before the recording stop operation, and the normal recording stop is not performed. However, since the TOC is recorded at the timing of the screen change detection, the recording of the scene 2 is started at the time of reproduction. From the time point (e) to the time point (e) when the screen change is finally detected, normal reproduction can be performed.

In the present embodiment, the screen change is detected by the difference between the frames. However, the screen change may be detected by another method. For example, as shown in FIG. 5, a histogram in one frame is obtained for the direction of the motion vector calculated by the motion compensation prediction circuit 113, and the correlation between the motion vectors in one frame is low (see FIG.
(B)) A screen change may be detected.

Next, a storage medium according to another embodiment of the present invention will be described. The above-described system of FIG. 1 can be configured by hardware, but can also be configured by a computer system having a CPU and a memory. When constituted by a computer system, the memory constitutes a storage medium according to the present invention. The storage medium stores a program for executing the processing described in the above embodiment.

As the storage medium, ROM, R
Semiconductor memory such as AM, optical disk, magneto-optical disk,
A magnetic storage medium or the like may be used, and these may be a CD-ROM,
The present invention may be applied to an FD, a magnetic card, a magnetic tape, a nonvolatile memory card, or the like.

Therefore, by using this storage medium in a system or apparatus other than the system shown in FIG. 1, the system or the computer reads out and executes the program code stored in the storage medium.
The same functions as those of the above embodiment can be realized, the same effects can be obtained, and the object of the present invention can be achieved.

An OS running on a computer
When performing part or all of the processing, or after the program code read from the storage medium is written to a memory provided in an extended function board or an extended function unit connected to the computer, Even when the CPU or the like provided in the extended function board or the extended function unit performs a part or all of the processing based on the instruction of the program code, the same functions as those of the above embodiment can be realized and the same effects can be obtained. Can be obtained, and the object of the present invention can be achieved.

[0032]

As described above, according to the present invention,
Since the index information such as TOC is recorded based on the screen change, even if the normal recording is not performed due to the power being turned off during the recording or the like, the reproduction is performed up to the middle of the scene, that is, the scene is reproduced. Can be recorded so that normal reproduction can be performed up to the last screen change point.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an image recording apparatus according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing screen rearrangement.

FIG. 3 is a configuration diagram showing an encoding order.

FIG. 4 is a timing chart showing recording timing of TOC.

FIG. 5 is a configuration diagram illustrating screen change detection.

[Explanation of symbols]

 104 Image Memory 105 Switch 106 Adder 107 DCT (Orthogonal Transform) Circuit 108 Quantization Circuit 109 Variable Length Encoding Circuit 110 Inverse Quantization Circuit 111 IDCT (Inverse Orthogonal Transform) Circuit 112 Adder 113 Motion Compensation Circuit 114 Switch 115 Buffer 116 Rate control circuit 117 Recording processing circuit 118 Recording medium 120 Screen change detection circuit 121 TOC memory 122 TOC control circuit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/85 H04N 5/85 Z F-term (Reference) 5C052 AA03 AB03 CC01 DD04 DD09 5C053 FA23 GB22 GB26 GB29 GB40 JA21 LA11 5D044 AB07 CC04 DE22 DE54 GK12 GL28 HL14 5D077 AA01 AA21 CA02 DC08 DC16 DC39 DF07 EA33 EA34 5D110 AA02 AA12 AA29 DA01 DA11 DC16 DC22 DE02 DE04 DE06 DF05

Claims (9)

[Claims] 1. A detecting means for detecting a screen change of input image data, and said image data being recorded on a recording medium, and index information relating to said image data in response to said detecting means detecting a screen change. An image recording apparatus, comprising: a recording processing control unit for recording the image on the recording medium. 2. A storage means for temporarily storing the image data, and the image data stored in the storage means is read out at a rate higher than the rate of the input image data and supplied to the recording processing control means. And rate control means for
2. The image recording apparatus according to claim 1, wherein the recording processing control unit records the index information during a non-recording period when the image data is recorded on the recording medium. 3. The image recording apparatus according to claim 1, wherein said detecting means detects a screen change according to a comparison result between a difference value between frames of said image data and a predetermined value. 4. The image recording apparatus according to claim 1, wherein said detecting means detects a screen change in accordance with a dispersion state of a direction of a motion vector in one frame of said image data. 5. The image processing apparatus according to claim 1, wherein the detecting unit detects a screen change according to a comparison result between a difference value between frames of the image data and a predetermined value, and a dispersion state of a direction of a motion vector in one frame of the image data. The image recording apparatus according to claim 1, wherein the detection is performed. 6. The image recording apparatus according to claim 1, wherein the recorded image data is data that has been subjected to variable length coding. 7. The image recording apparatus according to claim 1, wherein said index information is recorded in a predetermined dedicated area of said recording medium. 8. A procedure for detecting a screen change of input image data, a procedure for temporarily storing the image data, and a rate for storing the stored image data higher than a rate of the input image data. Reading the image data on a recording medium; and storing the index information on the image data in a non-recording period of the image data in response to the detection of the screen change. And an image recording method. 9. A process for detecting a change in screen of input image data, a process for temporarily storing the image data, and a process for storing the stored image data at a rate higher than the rate of the input image data. A process of reading the read image data on a recording medium; and a process of recording index information on the image data in a non-recording period of the image data in response to detection of the screen change. A computer-readable storage medium storing a program for executing a process of recording on a computer.