KR100220700B1 - Apparatus for measuring a head shape in a 3 dimension model-based coding system - Google Patents

Abstract

The present invention relates to an apparatus for extracting a three-dimensional head shape of a sender in a three-dimensional model-based coding system, which is formed in a headphone type for measuring the length of the head of the sender by covering both ears about the head of the sender head. A first constituent member and a second constituent member in the form of a headband measuring the curvature of the circumference of the sender's head by being circumscribed around the sender's head, the first constituent member passing horizontally through the center of the two eyes of the sender's head. A band resistance sensor for measuring the distance to the point (P1) and the distance to the intersection point P2 of the ear and the head of the sender head, wherein the second component is the bending, the back of the forehead of the sender head By configuring as a band resistance sensor for measuring the curvature of the forehead and the forehead curvature, it is possible to extract the head shape of the transmitter.

Description

Head shape extraction device of 3D model-based coding system

The present invention relates to a facial expression change coding system using a three-dimensional model, in particular a human three-dimensional model, and more particularly to an apparatus for extracting the shape of the head in the three-dimensional model-based coding system.

Application techniques using three-dimensional object models, especially human shape models, have been applied in the field of video coding and computer graphics. In the field of video coding currently underway, research to transmit a satisfactory image quality with a smaller amount of data continues. Looking at the research projects according to the amount of data to be transmitted, there is MPEG4, which starts from HDTV and is currently being actively studied. In MPEG4, a video signal is transmitted using a very small amount of data. Therefore, not only a transformation using information theory, for example, a cosine transform coefficient method, but also other computer vision, The techniques used in computer graphics are also applied.

In general, the shape of a person seen in a videophone or video conference only shows the chest above the waist. In particular, the speaker's face takes up most of the video information transmission. If only non-human face information, ie background information, can be ignored and only regular information on the face shape can be sent, the transmission rate can be greatly reduced. In other words, it finds the rules of the general face, face, expression, and emotions of the face and mouth when speaking, and sends them to the other party through one code. By deforming the face shape according to the received code, the expression shape of the sender may be recognized with a small amount of data.

More specifically, the three-dimensional model-based coding system targets coding in which two people talk in real time, such as a video phone, and transmit not only sound but also a changing face or body in real time. However, unlike general video coding, the transmitted data does not handle an image composed of pixels that change every moment. Instead, it extracts and transmits a certain motion variable, and then has the data on the receiving side, that is, the face of the sender. It is combined with the dimensional head shape model, body shape model, etc. to form the face or body image of the final changer after reconstruction.

Of course, such a system configuration can be used when the amount of data to be transmitted is very limited by the data transmission bandwidth, but not a large amount, but requires sufficient image quality for accurate recognition between the two parties. If the bandwidth is large enough to send enough data, the advantage of this system will be that low. This is because regular code lacks a natural look.

In order to express the sender's face images mutually transmitted in the 3D model-based coding system, a three-dimensional model of a general human head and a sender's face image to be overlaid on the model are basically required. That is, because each person has a different shape of the head, the sender will need to send a picture of his face and data about his head in advance in order for the receiver to see the sender's face.

Therefore, an object of the present invention is to provide an apparatus for extracting data on the shape of a sender's head in a three-dimensional model-based facial expression coding system.

According to the present invention for achieving the above object, the apparatus for extracting the three-dimensional head shape of the sender in the three-dimensional model-based coding system is to measure the length of the sender head by covering both ears around the parietal head of the sender head And a second structural member which measures the curvature of the circumference of the transmitter head by being covered by the first structural member and the circumference of the transmitter head.

1A and 1B are diagrams illustrating a state of use of a head shape extracting apparatus of a 3D model based coding system constructed according to a preferred embodiment of the present invention.

2A and 2B show characteristic curves of the length sensor and the length sensor shown in FIG. 1, respectively.

3A to 3B show characteristic curves of the vance resistance sensor and the band resistance sensor shown in FIG. 1, respectively.

FIG. 4 is a diagram illustrating an apparatus for converting information about a hair shape measured by a hair shape extracting device of the present invention into a signal for transmission; FIG.

* Explanation of symbols for main parts of the drawings

12: length sensor 14,22,24: band sensor

26: fixed frame 25: parietal

60: A / D converter

The above and other objects and various advantages of the present invention will become more apparent from the preferred embodiments of the present invention described below with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1A and 1B, an apparatus for extracting a three-dimensional head shape of a sender for use in a three-dimensional model-based coding system according to the present invention is shown. The head shape extracting apparatus of the present invention has a head-shaped first component member 10 which covers the ears 35 and 54 around the crown 35 of the sender head 30 and the sender head 30. And a second constituent member 20 in the form of a braided headband.

The first component member 10 is formed of the length sensor 12 and the sender head 30 that measure the length from the crown 35 of the sender head 30 to any position P1 or P2 of the sender head. The crown band sensor 14 which measures the curvature of the crown 35 part is provided.

The second constituent member 20 is a forehead band sensor 22 for measuring the curvature of the forehead of the sender head 30, a forehead band sensor 24 for measuring the curvature of the back of the head and the forehead band sensor 22 and the forehead. And a fixing frame 26 which connects the band sensor 24 and fixes the second component member 20 to the sender head.

2A shows a detailed configuration of the length sensor. The length sensor 12 may be implemented using a general band resistance, and is composed of a band resistance member 16 and a slider 18 slidable with respect to the length direction of the band resistance member 16. As can be seen from FIG. 2B, the length sensor 12 has a characteristic that the output voltage is directly proportional to the change in the resistance value generated by the band resistance member 16. Accordingly, the distance L1 from the crown 35 to the position P1 of the transmitter head 30 by detecting the change in the output voltage output by moving the band resistance member 16 from the point A of the original position to the desired position point B. ) And the distance L2 from the position P1 to the position P2 can be measured.

3 shows a detailed configuration of the band sensor. The band sensor 20 may be implemented using a general band resistance sensor. As can be seen from FIG. 2B, the band resistance sensor 20 has a characteristic that the output voltage changes linearly with the angle of refraction. Therefore, by detecting the fluctuation of the output voltage corresponding to the deflection state in which the band sensor 20 is bent, the degree of curvature S1 of the parietal portion of the transmitter head 30, the degree of curvature S2 of the front forehead and the degree of curvature of the rear head are detected. The degree S3 can be measured.

In order for the data value measured from each sensor described above to be effectively used for the three-dimensional model, the measurement position information for calculating each data is also important. Therefore, if the relative position information between each sensor is given, and if a reference position corresponds to any part of the 3D model, it is not necessary to measure the position of each sensor every time the transmitter changes. . Therefore, in the present invention, the reference point is defined as the point P1 passing horizontally through the center of the eyes of the sender and the intersection point P2 between the ear and the crown 35.

The distance L1 from the crown 35 to the point P1 measured in this way, the distance L2 from the point P1 to the point P2, the bending degree S1 of the crown 35, the bending of the forehead The degree S2 and the degree of bending S3 of the rear head are provided to the data conversion apparatus shown in FIG. 3, respectively.

The data conversion device composed of the analog-to-digital (A / D) converter 60 converts the voltage value output from each sensor into a digital signal, and converts the distance L1, the distance L2, and the bending degree S1. Digital information about (S2), (S3) is transmitted to the receiver.

As described above, in the three-dimensional object model-based coding system, the sender's head shape provided to the receiver can be easily extracted by using a band sensor and a bending sensor. Reconstructed in conjunction with a three-dimensional head shape model, it can be used as an important component of the final changing face or body shape of the sender.

Claims (8)

An apparatus for extracting a 3D head shape of a sender in a 3D model based coding system, A first constituent member for measuring the length of the sender's head by covering both ears about the crown of the sender's head; And a second constituent member for measuring the curvature of the circumference of the sender's head by being circumscribed around the sender's head. 2. The crossing point P2 of claim 1, wherein the first component member measures a distance to a point P1 horizontally passing through a center of two eyes of the sender's head, and the ear and the crown of the sender's head. 3D head shape extraction apparatus of the transmitter, characterized in that it comprises a second sensor for measuring the distance to. 3. The transmitter according to claim 2, wherein the first and second sensors of the first component are band resistance sensors having characteristics in which the output voltage is directly proportional to the change in the resistance value generated by the variation in the longitudinal direction. 3D head form extraction device. 4. The apparatus of claim 3, wherein the first component member has a headphone shape. The method of claim 1, wherein the second member is a forehead bend measuring sensor for measuring the bending of the forehead portion of the transmitter head, a back head bend measuring sensor for measuring the bending of the back head and the forehead bend measuring sensor and the back head bending measurement And a fixing frame for connecting a sensor and fixing the second component to the sender head. 6. The transmitter of claim 5, wherein the forehead flexure measurement sensor and the forehead flexure measurement sensor of the second constituent member include a band resistance sensor having a characteristic that the output voltage changes linearly according to the angle of refraction. Dimensional hair form extraction device. 7. The apparatus of claim 6, wherein the second component member has a headband shape. 3. The transmitter of claim 2, wherein the first component further comprises a band resistance sensor having a characteristic in which the output voltage changes linearly with the angle of refraction to measure the curvature of the parietal of the transmitter head. 3D head form extraction device.