JPH077745A - Special mobile body picture extract device - Google Patents

Abstract

PURPOSE:To transmit the smooth operation of a mobile body picture and to make a special mobile body remarkable by a colored picture of the body. CONSTITUTION:The device is provided with a picture signal separation part 11 separating a given picture signal into a luminance signal (Y) component and color signal (Cr, Cb) components, a motion compensation inter-frame prediction part 19 detecting a motion, and a color signal control part 16 controlling transmission of color information of a relevant picture from a motion vector obtained through motion compensation inter-frame prediction. Thus, only a picture of a part from which a motion is detected is formed to be a color picture and the information quantity is reduced more than the case of transmission of the entire picture as the color picture and the information quantity of a motion of a mobile object is increased and a picture with smooth motion is obtained. Furthermore, a picture of a special mobile body is extracted by setting a color to a mobile object desired to be notified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a special moving object image extraction for extracting a person or the like reflected in a security camera or a special moving object image for monitoring a vehicle or the like reflected in a traffic monitoring camera. More specifically, the apparatus uses motion-compensated inter-frame prediction to transmit a luminance signal component to a non-moving portion and a luminance signal component and a chrominance signal component to a moving portion, and The present invention relates to a special moving object image extraction device capable of reducing the amount of information and extracting a moving image by color.

[0002]

2. Description of the Related Art In recent years, with the development and popularization of digital transmission lines and the advancement of image processing technology, effective utilization of image information services is expected due to the development of high-speed digital signal processing and LSI technology therefor. In particular, in the division of communication, research on high-performance networks that can efficiently transmit image information is actively underway.
It is expected that a very high quality image transmission service represented by N (Integrated Services Digital Network) will be provided.
Further, it is expected that the image information will be used efficiently in fields other than communication.

In general, the amount of information contained in image information is very large, and if the image signal is handled as it is, the transmission rate becomes considerably high, which is not realistic. However, the information amount of the image signal includes a lot of redundancy, and the information amount can be reduced by removing this redundancy.
Therefore, an image coding method for that purpose has been actively studied. The image signal includes temporal information such as movement and change, and spatial information regarding the content of one image frame, and each has redundancy. In particular, in an image (moving image) signal, the correlation between consecutive frames is strong, and the amount of information can be significantly reduced by reducing the temporal redundancy. A motion-compensated interframe (field) predictive coding system is widely used as a coding system using such temporal correlation.

FIGS. 3A and 3B are diagrams for explaining the principle of a motion compensation predictive coding system which is one of the conventional image coding systems. In the motion compensation predictive coding method,
The image frame to be encoded and the previously encoded image frame are each divided into appropriate rectangular block areas, and comparison is performed for each block area. In an image frame in which a block that matches a target block to be coded is previously coded, a motion vector that indicates in which direction the matching block is located with respect to the block at the same position as the target block is detected. Then, the motion vector is used to represent the motion information included in the image signal, and the matching block in the video frame is set as the prediction value for the target block region.

FIG. 4 is a block diagram of a conventional image coding apparatus. In the figure, 31 is a motion compensation inter-frame prediction unit, 32 is a frame memory unit, 33 is a difference calculation unit, 34 is an error coding unit, and 35 is a frame calculation unit. Is an error decoding unit, and 36 is an addition unit. The input image signal is sent to the motion compensation prediction unit 31 in units of rectangular areas that do not overlap for each image frame. The motion compensation prediction unit 31 performs motion compensation prediction between the input image signal and an image signal input before the input image signal stored in the frame memory unit 32, and a motion vector is detected and output. It According to the result of the motion compensation prediction process,
The area determined to be the most appropriate is read from the frame memory unit 32 as a predicted value. The difference between the predicted value and the input image signal is obtained by the difference calculation unit 33,
The prediction signal is output. The predictive encoded signal is sent to the error encoding unit 34. The error encoding unit 34 uses the correlation of the prediction error signal in the image frame to generate a DCT (Disc
Rete Cosine Transform: Discrete cosine transform) Appropriate encoding such as encoding is performed. The result is output as an encoded signal to the outside of the device together with the motion vector from the motion compensation prediction unit 31.

On the other hand, the coded signal is locally decoded by the error decoding unit 35 and a prediction error decoded signal is output.
The prediction error decoded signal is added again with the prediction value read from the frame memory unit 32 in the adding unit 36, and a reproduced image signal after encoding is obtained. The reproduced image signal is sent to and stored in the frame memory unit 32. When the coding of one image frame is completed,
The frame memory unit 32 stores a locally decoded image signal of the image frame and is used as a prediction value of motion compensation prediction of the next image frame to be encoded. In addition, as the handling of color signals, separation encoding is used in which a decoded signal is separated into a luminance signal and a color signal and encoded separately. This separation coding is also called component coding, and is adopted because it is easy to compress information in low transmission rate coding. FIG. 5 shows the mechanism of separation encoding. That is, the input image signal has a luminance signal (Y) component, a color signal (r) component, and a color signal (C
b) component is separated.

[0007]

As described above, when the image information is transmitted at a low transmission rate, the luminance signal (Y) and the chrominance signal (Cr.C
Since the signal of b) is transmitted, the basic amount of information is large.
Therefore, when the motion is large, a phenomenon called overflow, which exceeds the limit of error coding in motion-compensated interframe prediction, occurs. Therefore, the motion of an object having a violent motion is not transmitted as a smooth motion. Further, in a simple color image, there is a problem that it is not clear to distinguish a moving object or the like from a stationary background or the like.

The present invention has been made in view of the above circumstances, and reduces the amount of information to be transmitted to make the movement of a moving body image smoother and to make the moving body image noticeable. The purpose is to provide an extraction device.

[0009]

In order to achieve the above object, the present invention provides an image signal separation unit for separating an input image into a luminance signal (Y) and a color signal (Cr / Cb), and a motion A color signal control unit that controls transmission of a color signal according to information, an encoding unit that encodes each of the luminance signal and the color signal, a decoding unit that decodes the encoded signal, and detects a motion,
A motion-compensated inter-frame prediction unit that transmits a motion vector,
It is characterized by including a frame memory unit for accumulating a previous frame, an error encoding unit for encoding the difference between the previous frame image and the current frame image, and an error decoding unit for decoding the difference. .

[0010]

In the moving object image extracting apparatus of the present invention, when an image signal is input, the image signal separating unit separates the luminance signal (Y) and the color signal (Cr.Cb). In the chrominance signal control unit, when motion is not detected in the motion compensation inter-frame prediction unit, only the encoded luminance signal information is output without outputting the separated and encoded chrominance signal information. . In the case of a moving image in which motion has been detected by the motion compensation interframe prediction unit, the color signal control unit outputs color signal information. That is, when transmitting an image, only a luminance signal component is transmitted to a non-moving portion, a luminance signal component and a color signal component are transmitted to a portion where motion is detected, and only a moving portion is colored. A moving object is extracted by focusing on a moving object. Further, since the amount of information as a whole is reduced, smoother tracking image information of the moving body is transmitted even at transmission at a low transmission rate.

[0011]

Embodiments will be described below with reference to the drawings. FIG. 1 is a configuration diagram for explaining an embodiment of a special moving object image extraction device according to the present invention. In the figure, 11 is an image signal separation unit, 12 is a luminance signal error encoding unit, and 13 is a color signal error. Encoding unit, 14 is a luminance signal error decoding unit, 15 is a color signal error decoding unit, 16 is a color signal control unit, 17 is a color signal frame memory unit, 18 is a luminance signal frame memory unit, and 19 is a motion compensation frame. An inter-prediction unit, 20 and 21 are difference calculation units, 22 and 23 are addition units, and 24 is a switch.

The input image signal is input to the image signal separating section 1
1 separates the luminance signal (Y) and the color signal (Cr, Cb). Separated luminance signal (Y) and color signal (Cr,
In Cb), the difference from the previous frame image is calculated by the difference calculation units 20 and 21, respectively, and the prediction error signal is obtained. Each of the prediction error signals is input to the luminance signal error encoding unit 12 and the color signal error encoding unit 13 to obtain an encoded signal. The respective encoded signals are input to the luminance signal error decoding unit 14 and the chrominance signal error decoding unit 15, respectively, and the decoded signals for obtaining the decoded signals are added with prediction values by the addition units 22 and 23, respectively. Are stored in the color signal frame memory unit 17 and the luminance signal frame memory unit 18, respectively.

On the other hand, the input image signal is input to the motion-compensated inter-frame prediction section 19 to detect the motion and transmit the motion vector. The motion compensation inter-frame prediction unit 19
The motion information from the color signal control unit 16 is input to the color signal control unit 16, and the color transmission control signal from the color signal control unit 16 turns on / off the switch 24 connected to the color signal error encoding unit 13 to output the color signal. Output information.

That is, assuming that an image signal is input, the image signal separating unit 11 separates the luminance signal (Y) component and the chrominance signal (Cr.Cb) component, and then the separated signal component. Each is DCT-transformed (discrete cosine transform), quantized, coded, and transmitted. A part of the data is stored in the frame memory units 17 and 18. Since the previous image frame is not stored in the frame memory units 17 and 18, no motion is detected by the motion compensation inter-frame prediction unit 19 in the first image, and thus the switch 24 is turned off by the color signal control unit 16. Therefore, only the encoded luminance signal (Y) component is output. Therefore, a monochrome image based on only the luminance signal component is output, and the amount of information transmitted is small.

Subsequently, when an image signal including a moving body image is input, the motion compensation inter-frame prediction unit 19 detects the motion and the motion vector is transmitted. At this time, since the motion information is transmitted, the color signal control unit 16 turns on the switch 24 of the image portion corresponding to the motion information, and the error of the encoded color signal is transmitted. For this reason, only the moving body image is colored, and like the conventional function of the motion-compensated inter-frame prediction unit 19, the information of the portion in which the motion is detected is transmitted, and the information of the moving body color image is transmitted. to continue.

FIG. 2 is a flow chart for explaining the operation of the special moving object image extracting apparatus according to the present invention. Hereinafter, each step will be described in order. First, an image signal is input (step 1), and the image signal is separated into a luminance signal and a color signal (step 2). Next, the motion-compensated inter-frame prediction unit performs motion compensation processing (step 3) and detects a motion vector (step 4). Next, a difference operation is performed on the separated luminance signal and chrominance signal to obtain a prediction error signal (step 5), and each encoding process is performed to obtain an encoded signal (step 6). In step 4, color signal transmission control is performed based on the detected motion information (step 7). The st
After the processing of ep6 and step 7, the coding result is output (step 8) and the procedure returns to step 1. The luminance signal and the chrominance signal encoded in step 6 are decoded (step
9) Then, the predicted value is added (step 10), the result is stored in the frame memory unit (step 11), and the process returns to step 3.
In this way, the amount of information as a whole is further reduced and only the moving body image is colored, so that the moving body image can be focused and the moving image can be extracted by color.

[0017]

As is apparent from the above description, according to the present invention, an image without motion transmits only a luminance signal and an image with motion transmits a luminance signal and a color signal. The amount can be reduced, and thus image communication can be performed in a communication network with a low transmission rate. Further, by using the moving object image extracting device of the present invention, it is possible to extract a moving object even at a long distance using a network having a low transmission rate.

[Brief description of drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of a special moving object image extraction device according to the present invention.

FIG. 2 is a flowchart for explaining the operation of the special moving object image extraction device according to the present invention.

FIG. 3 is an explanatory diagram for explaining the principle of conventional motion compensation predictive coding.

FIG. 4 is a configuration diagram of a conventional image encoding device.

FIG. 5 is a configuration diagram of an image signal separation device in conventional separation encoding.

[Explanation of symbols]

11 ... Image signal separation unit, 12 ... Luminance signal error coding unit,
13 ... Color signal error encoding unit, 14 ... Luminance signal error decoding unit, 15 ... Color signal error decoding unit, 16 ... Color signal control unit,
17 ... Color signal frame memory unit, 18 ... Luminance signal frame memory unit, 19 ... Motion compensation inter-frame prediction unit, 20,
21 ... Difference calculator, 22, 23 ... Adder, 24 ... Switch.

Claims (1)

[Claims] 1. An image signal separation unit that separates an input image into a luminance signal and a color signal, a color signal control unit that controls transmission of the color signal based on motion information, and the luminance signal and the color signal are coded respectively. An encoding unit for encoding, a decoding unit for decoding the encoded signal, a motion compensation inter-frame prediction unit for detecting motion and transmitting a motion vector, a frame memory unit for accumulating the previous frame, and A special moving object image extraction device comprising: an error coding unit that codes a difference between a frame image and a current frame image; and an error decoding unit that decodes the difference.