JP2733953B2 - Coding and decoding of video signals - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal encoding / decoding system for transmitting a video signal input from a television camera or the like.

(Prior Art) In an encoding / decoding method of a moving image signal used in a video conference or the like, a moving image signal input from a television camera or the like is encoded and transmitted via an analog or digital communication path. , Are decoded and displayed on the receiving side. At this time, in order to use a narrow band communication path, the moving image signal is encoded by a highly efficient encoding method.

For example, when a normal NTSC signal is represented by digital data, the information amount is 60 M to 100 M bits per second. In actual video conferencing, this video signal is encoded and converted to 64
Transmission is performed with a code amount of about 1.5 Mbit / sec from k. Therefore, the compression ratio of the encoding ranges from 1/40 to 1/1000.

(Problems to be Solved by the Invention) In the conventional encoding / decoding method of a moving image signal, a moving image signal input from a television camera or the like is directly encoded and transmitted. Therefore, the receiving side only displays the decoded moving image. However, for example, when a moving image with a large number of subjects is transmitted in a video conference or the like and the observer on the receiving side is paying attention to the speaker, the only information truly needed on the receiving side is the speaker's part. It is desirable that the up of the speaker can be displayed on the receiving side.

In particular, an image decoded when a narrow-band communication path is used has a lot of deterioration. Therefore, it is possible to display the portion of interest more finely by transmitting the image by zooming only the portion that the observer on the receiving side pays attention to.

In the case where such a method is realized by a conventional method, a television camera is operated on the transmission side, or moving image signals output from a plurality of television cameras are switched and transmitted.
However, these are processes on the transmitting side, and do not always match the intentions of the observer on the receiving side.

Also, in order to reflect the intention of the observer on the receiving side, the observer is required to input some information, transmit control information from the receiving side to the transmitting side, and perform the operation and switching of the TV camera on the transmitting side on the receiving side. A method is also conceivable. However, there is a problem that such an operation is complicated and places a large burden on an observer.

The present invention recognizes the position of the line of sight of the observer on the receiving side and transmits it to the transmitting side, and the transmitting side encodes and transmits only the portion of interest of the observer on the receiving side, thereby transmitting the image on the receiving side. It is an object of the present invention to provide a moving picture signal encoding / decoding system capable of displaying only a portion of interest to a viewer with high precision.

(Means for Solving the Problems) The encoding / decoding method for a moving image signal according to the present invention includes: decoding means for decoding a code transmitted from a transmitting side on a receiving side; and displaying the decoded moving image. Screen, recognition means for recognizing the position of the line of sight of the observer on the screen, transmission means for transmitting the position of the line of sight to the transmitting side, and position of the line of sight receiving the position of the line of sight from the receiving side on the transmitting side Determining means for determining a position and a range of a moving image to be transmitted based on a temporal variation of the input image; input means for inputting the moving image according to the position and the range; and encoding the moving image and receiving a code And encoding means for transmitting the data to the transmission side.

(Operation) An encoding / decoding method for a moving image signal according to the present invention will be described.

The receiving side decodes the code transmitted from the transmitting side and displays the moving image on the screen. Then, the position of the line of sight of the observer on the decoded display screen on the screen is recognized, and this is transmitted to the transmission side.

The transmitting side receives the position of the line of sight transmitted from the receiving side, and determines the position and range of the moving image to be transmitted based on this position. The position and range of the moving image indicate where in the subject to transmit, and correspond to, for example, the camera angle and zoom of a television camera.

A moving image is input based on the position and range determined in this way. As for this input method, in addition to the method of actually controlling the camera and switching its angle and zoom, it is also necessary to switch and use moving images input by multiple cameras or to select from moving images captured in a wide range There are various methods, such as cutting out and inputting only the necessary part.

Then, the input moving image is encoded and the code is transmitted to the receiving side. As this encoding method, various encoding methods for moving image signals, such as predictive encoding and transform encoding, can be used.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First
FIG. 1 is a block diagram showing an embodiment of a video signal encoding / decoding system according to the present invention. As shown in FIG. 1, the decoding means 1 on the receiving side decodes the code 100 transmitted from the transmitting side and displays the moving image 101 on the screen 2.

FIG. 2 is an explanatory diagram showing a screen to be displayed. Second
As shown in the figure, the position of the line of sight of the observer on the screen 2
102 is recognized by the recognition means 3. This recognition means 3 can be easily realized by using an apparatus called an eye mark recorder. Further, by inputting and processing an image in which the observer is a subject, and detecting the movement of the observer, the position of the observer's line of sight on the screen 2 can be recognized. The position 102 of the line of sight thus recognized is transmitted to the transmitting side via the transmission means 4. Since the information of the line-of-sight position 102 is very small, it can be transmitted over a narrow band (for example, a 300-baud serial line).

Upon receiving the line-of-sight position 102, the transmitting-side determination means 5
A center position 103 and a range 104 of a moving image to be transmitted are determined based on the line-of-sight position 102. FIG. 3 is an explanatory diagram showing a method for determining the position and range of a moving image to be transmitted. As shown in FIG. 3, the position of the line of sight 102 on the screen 2 fluctuates with time. Therefore, for example, the center 103 of the moving image to be transmitted at the center of the line-of-sight position 102 within a certain time
And

Then, according to the range of the temporal variation, if the variation is large, the range 104 of the moving image to be transmitted is increased so that the entirety can be transmitted, and if the variation is small, the range 104 is reduced. The part indicated by the position 103 is transmitted up.

Next, based on the position 103 and the range 104 of the moving image determined by the determining unit 5, the input unit 6 inputs the moving image 105. In actuality, the input means 6 automatically controls the television camera to photograph the position indicated by the position 103,
Zoom is performed using the value indicated by 04, and a moving image 105 is input. In addition to such a method, there are various methods such as switching and using moving images input by a plurality of cameras, and cutting out and inputting only a necessary part from a moving image captured in a wide range. .

Then, the encoding means 7 encodes the input moving image 105 and transmits the code 100 to the receiving side. As this encoding method, various encoding methods for moving image signals, such as predictive encoding and transform encoding, can be used.

However, at the time when encoding is started in such processing on the transmitting side, the line-of-sight position 102 has not yet been transmitted from the receiving side. Therefore, only at the time of starting the encoding, the range 104 is determined as large as possible without using the line-of-sight position 102. As a result, a moving image captured in a wide range can be transmitted, so that a necessary portion can be gradually narrowed down using the line of sight 102.

Also, since only the moving image 105 indicated by the position 103 and the range 104 is encoded and transmitted in this way, it is necessary for the receiving side observer with a smaller amount of information compared to a case where the entire image is constantly encoded and transmitted. Images can be displayed. In addition, when the amount of information that can be transmitted is limited, only the part that the observer is watching can be transmitted more precisely.

Further, there is no need for the receiving observer to perform any complicated operation.

(Effect of the Invention) The position of the line of sight of the observer on the receiving side is recognized and transmitted to the transmitting side, and the transmitting side encodes and transmits only the part of the observer's attention, thereby transmitting the observer on the receiving side. Only the part of interest can be transmitted and displayed precisely.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a moving picture signal encoding / decoding system according to the present invention, FIG. 2 is an explanatory view showing a screen to be displayed, and FIG. It is explanatory drawing which shows the determination method with a range. In the figure, 1 ... decoding means, 2 ... screen, 3 ... recognition means, 4 ...
... Transmission means, 5 ... Determining means, 6 ... Input means, 7 ...
Encoding means.

Claims (1)

(57) [Claims] 1. A decoding means for decoding a code transmitted from a transmission side on a reception side, a screen for displaying a decoded moving image, and a recognition means for recognizing a position of a line of sight of an observer on the screen. Transmitting means for transmitting the position of the line of sight to the transmitting side, and determining the position and range of the moving image to be transmitted based on the temporal variation of the position of the line of sight received at the transmitting side from the receiving side. Determining means, input means for inputting the moving image in accordance with the position and range, and encoding means for encoding the moving image and transmitting a code to a receiving side. Encoding / decoding method.