JPH06350984A - Moving picture compression/expansion system - Google Patents

Abstract

PURPOSE:To expand transmitted compressed moving pictures, to overlap them with the other pictures and to display them. CONSTITUTION:A header adding means 17 adds a header including the color code of a background to compressed moving picture data outputted by a moving picture compression means 16 and outputs them, a header separation means 45 separates the header from the compressed moving picture data to which the header is added and takes out the color code of the background and a moving picture expansion means 46 expands the compressed moving picture data and obtains the picture data of the moving pictures. A priority generation means 47 compares the picture data of the moving pictures outputted from the moving picture expansion means with the color code of the background from the header separation means and generates priority data for instructing a foreground part or a background part by a picture element unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving picture compression / expansion system, and more particularly to a moving picture compression / expansion system for compressing and transmitting or recording a moving picture and expanding the moving picture to obtain a moving picture.

[0002]

2. Description of the Related Art Conventionally, there are high-efficiency moving image compression techniques such as MPEG (Moving Picture Experts Group), FST (Four Square Transfer), and DVI (Digital Video Interactive). If such a moving picture compression technique is used, a moving picture is recorded on a recording medium such as a CD-ROM (compact disc read-only memory) with a limited storage capacity and a relatively low data transfer rate, and this is recorded in real time. It is possible to play.

[0003]

In a game machine or the like, a foreground image of a character or the like appearing in the game is superimposed on a background image to display the game.

In this case, the foreground image has, for each pixel, priority data indicating the foreground portion or the background portion together with the RGB color data, and at the time of synthesis, the foreground image data corresponding to the priority data. Alternatively, the background image data is selected and the images are displayed in an overlapping manner.

Even if the above foreground image is used as a moving image and the moving image is to be compressed, conventional moving image compression techniques such as MPEG can only compress moving image data composed only of color data and include priority data. There is a problem in that the moving image data cannot be compressed, and the images cannot be superimposed and displayed using the moving image compression technique.

The present invention has been made in view of the above points,
An object of the present invention is to provide a moving picture compression / expansion system capable of expanding a compressed moving picture and displaying it by superimposing it on another image.

[0007]

A moving picture compression / expansion system of the present invention comprises a moving picture compression means for compressing image data of a moving picture whose foreground is moving on the background, and a compressed moving picture data outputted by the moving picture compression means for converting the background Header adding means for adding and outputting a header containing a color code, header separating means for separating the header from the compressed moving image data to extract the background color code, and compression output by the header separating means A moving picture decompressing unit for decompressing the moving picture data to obtain moving picture image data, and comparing the moving picture image data output from the moving picture decompression means with the background color code from the header separating means to determine whether the foreground part is the background part And a priority generation unit that generates priority data instructed in pixel units.

[0008]

In the present invention, the header including the background color code is added to the compressed moving image data, and the background color code is taken out from the header added to the compressed moving image data to generate the priority data. Therefore, this priority data is used. The decompressed moving image can be displayed by being superimposed on another image such as a background image.

[0009]

1 and 2 are block diagrams of a compression system and a decompression system of an embodiment of the system of the present invention.

In the compression system of FIG. 1, the video camera 12
The moving image picked up in step 1 or the moving image reproduced by the video tape recorder 13 is selected by the switch 14 and supplied to the D / A converter 15. Here, as shown in FIG. 3A, the moving image has a foreground 31 with a blue screen as the background 30, for example.
Is a moving image.

The D / A converter 15 separates the RGB components of the video signal of the moving image, quantizes each color with, for example, 5 bits, and outputs it as image data of 15 bits per pixel. This image data is supplied to the moving picture compressor 16. The moving picture compressor 16 is, for example, an MPEG encoder, performs high-efficiency moving picture compression in units of 15 frames, and supplies it to the header addition circuit 17.

The header addition circuit 17 is supplied with a 15-bit color code for specifying the color of the background 30 from the terminal 18. The header adding circuit 17 adds a header including a background color code for designating the background color to the compressed moving image data for a display time of 0.5 seconds, that is, for 15 frames, to form a transmission signal of the format shown in FIG. , A CD-ROM, a hard disk, etc. to record on a recording medium, and also to a transmitter 21 to send out to a communication line 22.

In the expansion system of FIG. 2, the reproducing device 42 reproduces the transmission signal from the recording medium recorded by the recording device 20 and supplies it to the switch 43, and the receiver 44 uses the communication line 22.
Is received and supplied to the switch 43. The combined data selected by the switch 43 is supplied to the header separator 45, where the header of the transmission signal shown in FIG. 4 and the compressed moving image data are separated. The separated compressed moving picture data is supplied to the moving picture decompressor 46, and the header separator 45 extracts the background color code from the separated header and supplies it to the chroma key detector 47. Video expander 4
An MPEG decoder 6 decompresses the compressed moving picture data to restore the moving picture image data and supplies it to the chroma key detector 47.

The chroma key detector 47, which is a priority generating means, compares the moving image data with the background color code pixel by pixel, and if the values match, the value is 0, and if the values do not match, the value is 1. Generate a bit. For example, when the background color code is blue in the image composed of the blue background 30 and the foreground 31 shown in FIG.
As shown in (B), the background value is 0 (shown in black),
A priority bit having a value of 1 (shown in white) in the foreground portion is generated.

The above-mentioned image data and priority bits are supplied to the input / output circuit (I / O) 61 in the image processing device 60, and written in the address designated by the CPU 62 of the character memory 63 on a pixel-by-pixel basis. On the character memory 63, the image data for one pixel is 16 as shown in FIG.
The lower 5 bits D0 to D4 represent a red level, the next 5 bits D5 to D9 represent a green level, the next 5 bits D10 to D14 represent a blue level, and the most significant bit D15. Is a priority bit.

The graphic processor 64 reads the image data of the foreground moving image stored in the character memory 63, performs processing such as enlargement, reduction, rotation, color calculation, etc., and writes it in the frame buffer 65. Further, the graphic processor 64 reads out the image data of the foreground moving image in the frame buffer 65, and at the same time, synchronizes the vertical and horizontal pixels with the image data of the background image stored in the frame buffer 66. (Not included) is read out, RGB data of the foreground moving image is selected when the priority bit added to the foreground moving image is 1, and image data of the background image is selected and supplied to the video encoder 70 when the priority bit is 0. . As a result, the video encoder 70 generates a video signal of an image in which the foreground moving image and the background image are combined and displays it on the monitor 72.

As described above, since the header including the background color code is added to the compressed moving image data and transmitted, and the background color code of the header is extracted from the transmission signal to generate the priority data, the priority data is decompressed. A moving image can be displayed by being superimposed on another image such as a background image.

It is also possible to display a plurality of moving images by superimposing one moving image on the frame buffer 65 and then further expanding another moving image.

[0019]

As described above, according to the moving picture compression / expansion system of the present invention, a compressed moving picture can be expanded and displayed by superimposing it on another image, which is extremely useful in practice.

[Brief description of drawings]

FIG. 1 is a block diagram of a compression system of the system of the present invention.

FIG. 2 is a block diagram of a decompression system of the system of the present invention.

FIG. 3 is a diagram for explaining the present invention.

FIG. 4 is a diagram showing a transmission data format.

FIG. 5 is a diagram showing an image data format of a moving image.

[Explanation of symbols]

 16 Video Compressor 17 Header Addition Circuit 21 Recording Device 22 Transmitter 42 Playback Device 44 Receiver 45 Header Separator 46 Video Decompressor 47 Chroma Key Detector

Claims (1)

[Claims] 1. A moving picture compression unit for compressing image data of a moving picture in which a foreground moves on a background, and a header addition for outputting a compressed moving picture data output from the moving picture compression unit by adding a header including a color code of the background. Means, a header separating means for separating the header from the compressed moving picture data to which the header is added and extracting the background color code, and a moving picture for decompressing the compressed moving picture data output from the header separating means to obtain moving picture image data A decompression means and a priority generation means for comparing the image data of the moving picture output from the moving picture decompression means with the color code of the background from the header separation means to generate priority data indicating the foreground part or the background part in pixel units. A moving picture compression / decompression system comprising: