JPH0965275A - Image editing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce data to be stored by providing each of means for generating array, data reception, array content reference and compression in addition to the number of frames between pictures and information so as to edit image data efficiently. SOLUTION: A computer 7 and an external device 15 are connected via a transmission line 14 and a box 13. A CPU 8 executes a basic program stored in a ROM 9 and a program 1 expanded in a memory 10. Data fed from the device 15 are transferred to a memory in a board 12, compressed and stored in a medium 11. The operator uses a device 17 to enter an instruction. The program 1 initializes the board 12 and the memory 10 is provided with an initial setting section 3, a table generating section 4, a data reception section 5 and an image compression section 6. A control section 2 controls all the modules.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image editing system, and more particularly, to a method for controlling an external device from a personal computer (PC) or the like to select an image material of a required scene and store it as data for a multimedia application. Related to the editing system.

[0002]

2. Description of the Related Art When an image is digitized and recorded on a storage medium such as a disk, the amount of data is enormous, so that the data is usually compressed and stored.

[0003] Among various types of compression coding, a coding method (frame coding) for performing discrete cosine transform (DCT) of an image and performing variable length coding of a conversion result by utilizing the property that the spatial frequency of the image is concentrated at a low frequency. There is a coding method (inter-frame coding) in which compression is performed using the correlation between images in the time direction of the image. JPEG (Joint Photographic E) which is an international standard for still image coding
xpert Group) uses the former method and uses MPEG (Moving) which is an international standard for video coding.
Picture Expert Group) uses a method that combines the former and the latter.

In MPEG, as shown in FIG. 3, intra-frame coding is performed for an I-picture, a difference from a temporally forward image for a P-picture, and temporally forward, backward or forward and backward for a B-picture. Take the difference with the interpolated image,
By encoding the difference value, encoding can be performed with higher efficiency than JPEG. The upper numbers in the figure indicate the order of the frames recorded on the medium, and the lower numbers indicate the processing order of the frames during encoding.

Using the former compression coding technique, P
Japanese Patent Application Laid-Open No. 5-260436 discloses an editing system which can control an external device from C to select an image material of a necessary scene and input, compress, and accumulate it in a PC. In addition, Vidcap., Which is an application operating on Windows 3.1. exe also performs the same processing.

FIG. 8 is a block diagram showing the configuration of the above system.

In FIG. 8, a PC and an external device are connected by a transmission line,
It is connected via an RS232C interface and an image board, and operates under the control of a program developed in a memory. In this system, the start / end time of an image material to be captured is set by an operator, and when an execution instruction is issued, an external device is controlled to transfer still image data to a PC.
The data is stored in the above memory, compressed using the intra-frame compression coding method, and then stored in a storage medium such as a disk. Thereafter, by repeatedly compressing and accumulating the image data while taking in the image data while advancing the frame until the end time, an image material of a necessary scene is selected and accumulated as data for a multimedia application.

[0008]

A problem with the conventional image editing system described above is that the external device is played back frame by frame in the time direction of reproduction while the PC
It is to take the image into the memory above and compress it.

Using this series of capturing means, JPE
An intra-frame encoding method such as G or a method of taking a difference (P picture) from an image temporally ahead of MPEG and encoding the difference value is possible, but temporally forward and backward MPEG temporally. Alternatively, since a difference (B picture) between an interpolated image formed from the front and the rear is obtained and a method of encoding the difference value cannot be used, image data cannot be efficiently stored.

[0010]

In order to achieve the above object, the present invention has the following means. (1) An II coefficient indicating the number of frames between the I picture and the next I picture input by the operator, and the number of B pictures between the I picture and the next P picture or the next I picture. Means for creating a GOP array from the B coefficients shown; (2) means for taking in image data for the number of frames for which an image can be predicted from the preceding and succeeding frames; and (3) means for creating an encoded array. The image data of the number of frames for which an image can be predicted from the frame is taken in from an external device, and the difference (B picture) between the temporally forward frame, the backward or the interpolated image created from the forward and backward frames is calculated. Since the difference value can be encoded, the amount of accumulated data can be reduced.

[0011]

Next, the present invention will be described with reference to the drawings. Hereinafter, mainly controlling an external device from a PC to select an image material of a necessary scene, fetching image data for the number of frames that can predict an image from the preceding and succeeding frames from the external device, and performing inter-frame compression. An embodiment of an editing system capable of reducing the amount of data to be stored will be described with reference to the configuration diagram of FIG.

In this embodiment, the PC 7 and the external device 15 exchange commands via the interface box 13 and all functions prepared by the external device 15, such as reproduction, stop, and pause, can be used from the PC 7. . The interface box 13 is provided with an interface such as RS232C that can perform bidirectional communication.

In the image editing system shown in FIG.
An external device 15 is connected via a transmission line 14 and an interface box 13, and a CPU 8 executes a basic input / output program (BIOS) stored in a ROM 9 and a program 1 expanded in a memory 10. External device 1
5 is input to the memory in the image board 12 and displayed on the display device 16 as it is. At the same time, the image data is transferred to the memory in the PC 7 according to the instruction of the program 1 and then compressed, and the It is recorded on the storage medium 11.

An operator inputs a command from a command input device 17 such as a keyboard or a pointing device.
The program 1 initializes the image board 12 and the memory 1
An initial setting unit 3 for securing a work area within 0, a table creation unit 4 including a unit for creating a start / end time table and a group of pictures (GOP) array of material taken from an operator's instruction, and a start / end Time table and GOP
The external device 15 and the image board 12 are controlled based on the arrangement,
Means for capturing image data for the number of frames for which an image can be predicted from the preceding and succeeding frames;
A data capturing unit 5 including means for transferring the data to the memory area 10 of C7 and creating an encoded array; and an image compressing unit 6 for compressing the captured data.
Control all modules.

Here, the image compression unit uses information indicating which picture in the GOP array the captured frame described in the coding array is to be used as, and the location of the memory to which the captured frame was transferred, and The sign I
A means comprising three types of compression means: a means for compressing a picture, a means for compressing a P picture which is an inter-frame code only in the forward direction, and a means for compressing a B picture which is a bi-directional inter-frame code before and after. I do.

With the above configuration, the PC 7 controls the external device 15 to select an image material of a necessary scene, and fetches from the external device 15 image data for the number of frames that can predict an image from the previous and subsequent frames. A process for performing inter-frame compression will be described.

FIG. 2 is a flowchart of the above process.
Program 1 was started according to the operator's instruction (S1)
Thereafter, the image board 12 is initialized (S2), and the connected external device 15 is started (S3).

The operator inputs a command from the instruction input device 17 to the external device 1.
5 and inputs the start / end time of capturing a required scene, an II coefficient indicating the number of frames between the I picture and the next I picture, and the I picture and the next P picture or the next I picture. And the B coefficient indicating the number of frames of the B picture between
An area for storing image data for the number of frames for which an image can be predicted from previous and subsequent frames as shown in FIG. 4 is secured in the memory 10 in C7 (S4).

Next, in the table creating section 4, the start / end time of the scene input by the operator is converted into frame units (S5) to create a start / end time table as shown in FIG. 5 (a). Yes (S6). The start / end time s1 in the figure indicates the start / end time of scene 1. Also, FIG.
(A) illustrates the table up to 20 scenes, but the table is not particularly limited to 20 scenes. After creation,
A GOP array as shown in FIG. 5B is created (S
7).

When a compression execution command is given by the operator, the data fetch unit 5 sets the start time s1 of the first scene.
(S8), pause (S9), fetch image data into the image board 12 (S10), transfer it to the memory 10 area (S11), and create an encoded array (S1).
2). It is confirmed whether or not the frame corresponding to the next I or P picture has been captured while referring to the GOP array (S1).
3) If the frame has not been captured, the processes of S9 to S13 are repeated while frame-by-frame advance is performed until the frame corresponding to the next I or P picture is captured (S14). When the image data is captured, the image compression unit 6 performs inter-frame compression processing (S15), and stores the processed data in the storage medium 11 (S16).

Subsequently, it is confirmed whether it is the end time (S1).
7) When the end time is not ss1, frame advance is performed frame by frame until the end time ss1 (S18), and S9 to
Step 17 is repeated. At the end time ss1, it is confirmed whether there is any other table set (S19),
If there is, seek until the start time s2 of the next scene (S
20), and the processing of S9 to 19 is repeated until the end time s2. If not, the used memory area is released (S2
1), end the process.

FIG. 6 is a flowchart of the means for creating a GOP array.

The table creator 4 clears the counter variable for determination (S22), and stores a value defining the I picture (hereinafter referred to as I value) at the head of the GOP array (S2).
3). In the present invention, I, P, and B are explicitly used, but are not particularly limited. The counter variable is GOP
Each time a value is stored in the array, 1 is added.

Then, it is determined whether the counter variable is equal to the I-I coefficient (S24).
The B value is stored in the OP array (S25), and the P value is stored (S25).
26), S until the counter variable equals the II coefficient
The processing of 25 to 26 is repeated. If they are equal, the process ends.

FIG. 5 (c) shows the structure of the coding array, and FIG. 7 (a) is a flowchart of the means for creating the coding array at the first compression. When the program 1 stores, in the initial setting unit 3, image data for the number of frames that can predict an image from the preceding and succeeding frames, it obtains a head position of a memory for storing each frame. (0 × 1000 to 0 × 40 in FIG. 4)
00).

As shown in FIG. 7A, the coding sequence is
Information describing which picture of I, B, or P is to be processed and the start position of the memory area to which the data has been transferred are described. The image compression unit performs compression based on this arrangement.

The image data is taken into the image board 12,
When the data is transferred to the memory 10 area, the data capturing unit 5 copies the value (I) corresponding to the frame captured from the GOP array to the picture constituting member of the encoding array (S27), 0 × 1000) is copied to the buffer configuration member (S28) and the variable A (S29). Continue to image board 1
2 (S30), transfers the image data to the memory 10 area (S31), copies the next value of the GOP array to the picture member (S32), and sets the head position of the memory area to which the data was transferred to the buffer configuration. Copy to the member (S33). Check the value of the GOP array (S34),
In the case of I or P, the next value of the GOP array is copied to a variable B (S35), the head position of the memory area to which the data is transferred is copied to a variable C (S36), and the encoded array is stored in a compression unit. Send (S37). In the case of B, the processing of S30 to S34 is repeated.

FIG. 7B is a flowchart of a means for creating an encoded array at the time of the second or subsequent compression. The last frame (P) captured last time needs to be used as a reference frame at the time of inter-frame compression. The present invention solves the problem by rearranging the top position of the memory area to which the data has been transferred without controlling the external device and taking in the image data.

The image data is taken into the image board 12,
When the data is transferred to the memory 10 area at the position indicated by the previously stored variable A, the value of the previously stored variable B is copied to the picture constituent member of the encoding array in the data capturing unit 5 (S38), and the variable C is buffered. Member (S3
9) and copied to the variable A (S40), the value (B) corresponding to the frame fetched from the GOP array is copied to the picture member of the coded array (S41), and the top position (0 .Times.1000) is copied to the buffer member (S42). Subsequently, the image data is fetched into the image board 12 (S43), transferred to the memory 10 area (S44), the next value of the GOP array is copied to the picture member (S45), and the top of the memory area to which the data was transferred is copied. Is copied to the buffer member (S46). Check the value of the GOP array (S
47) In the case of I or P, the next value of the GOP array is copied to a variable B (S48), the top position of the memory area to which the data is transferred is copied to a variable C (S49), and the encoded array is copied. The data is sent to the compression unit (S50). In the case of B, S43
To 47 are repeated.

[0030]

As described above, according to the present invention,
Using the means for loading images into the memory on the PC frame by frame while moving / stopping frames in the time direction of playback of the external device, and made from the front, back or front and back in time such as MPEG Since a method of obtaining a difference (B picture) from the interpolated image and encoding the difference value is used, it is possible to efficiently edit image data and reduce the amount of data to be stored.

[Brief description of drawings]

FIG. 1 is a configuration diagram of the present invention.

FIG. 2 is a flowchart of the entire process of the present invention.

FIG. 3 is an example of an MPEG picture configuration.

FIG. 4 is a diagram showing a memory area for storing image data.

FIG. 5 is a diagram showing tables and arrays according to the present invention.

FIG. 6 is a flowchart of a means for creating a GOP array.

FIG. 7 is a flowchart of a means for creating a coded array.

FIG. 8 is a configuration diagram of a conventional system.

[Explanation of symbols]

 1 Program 2 Main control unit 3 Initial setting unit 4 Table creation unit 5 Data acquisition unit 6 Image compression unit 7 PC 8 CPU 9 ROM 10 Memory 11 Storage medium 12 Image board 13 Interface box 14 Transmission path 15 External device 16 Display device 17 Instruction Input device

Claims (1)

[Claims] 1. An external device for reproducing image data from a recording medium, and a device including a CPU and capable of high-speed operation,
It is connected via a transmission path, interface box, and image board, and performs real-time compression encoding between frames between image data fetched from an external device on a frame-by-frame basis and image data before and after the frame and storing the data in a storage medium in real time. In the image editing system that cannot be processed by the I picture, the I-I coefficient which is the number of frames between the I picture inputted by the operator and the next I picture, and the I picture and the next P picture
Means for creating a GOP array which is an array indicating the configuration of a GOP from B coefficients which are the number of B pictures between a picture and an I picture; Means for capturing image data, information indicating which picture in the GOP array the captured frame is to be used as, and means for creating a coded array which is an array describing the location of the memory to which the captured frame has been transferred; Means for compressing I, P, and B pictures by referring to the contents of the coding array.