HK1190484A

HK1190484A - System and method for identifying human face

Info

Publication number: HK1190484A
Application number: HK14103450.1A
Authority: HK
Inventors: 林凡生
Original assignee: 盈泰安股份有限公司
Priority date: 2012-06-25
Filing date: 2014-04-10
Publication date: 2014-07-04

Abstract

The present invention discloses a system for identifying a human face, which includes a visible light camera, an infrared (IR) camera, a non-contact temperature sensing device and a processing unit. The visible light camera and the IR camera aim at a same photograph zone for respectively photographing at least one visible-light picture and at least one IR picture. The non-contact temperature sensing device senses a present target temperature in a temperature sensing zone, which is in the photograph zone. When the processing unit detects that a human face is existed in the corresponding zone of the visible-light picture and that of the IR picture, it determines if the present target temperature is in a body-temperature range. When the present target temperature is in the body-temperature range, the processing unit determines that the human face detected in the corresponding zone is an alive human face.

Description

Face judgment system and method

Technical Field

The invention relates to a face judgment system and a face judgment method.

Background

Since the face is an important biometric feature of humans, many face-related studies have been developed. One important application is face recognition, which performs identity authentication by comparing visual features of a human face through computer analysis. When the face recognition is used as the basis for the entrance guard control management, the management and construction cost of the induction card can be saved, and the trouble that people who enter and exit the entrance guard forget to bring the card can also be avoided. Compared with other biological feature identification methods, the human face identification method is performed in a non-invasive and non-contact manner and is easily accepted by most people. In particular, the benefits of face recognition techniques are particularly felt when both hands are free to swipe a card or press a password.

In addition, another important human face related study is human face detection. Face detection is often applied to detect and start face discrimination and tracking functions immediately when a suspicious moving object enters a set range of a monitoring camera, lock the moving object and judge whether the moving object is a suspicious intruder.

However, due to the explosion of the internet and social networks, photos and movies of the face of a person can be easily obtained by others. In addition, the technology of various output devices (such as printers, displays, etc.) is continuously advanced, and the output devices can output photos or films with high quality and high similarity. Therefore, the face recognition and detection system can be easily deceived or misled by using high-quality output photos or films.

Disclosure of Invention

Therefore, an aspect of the present invention is to provide a face judgment system for judging a living face by using a visible light photograph, an infrared light photograph and a sensed current target temperature. The human face judging system comprises a visible light camera, an infrared light camera, a non-contact temperature sensing device and a processing element. The processing element is connected with the visible light camera, the infrared light camera and the non-contact temperature sensing device. The visible light camera takes at least one visible light picture. The infrared camera takes at least one infrared photo. The visible light photo and the infrared light photo are obtained by respectively shooting the same shooting area by a visible light camera and an infrared light camera. The non-contact temperature sensing device senses a current target temperature for a temperature sensing area. Wherein, the temperature sensing area is located in the shooting area. The processing element comprises a face detection module and a temperature judging module. The face detection module detects whether a face exists in a corresponding block corresponding to the temperature sensing area in the visible light photo and the infrared photo respectively. When the human face exists in the corresponding block, the body temperature judging module judges whether the current target temperature is within a human body temperature range. When the current target temperature is within the human body temperature range, the processing element judges that the face detected in the corresponding block is a living face.

Therefore, another aspect of the present invention is to provide a face judgment method for judging a living human face by using a visible light photograph, an infrared light photograph and a sensed current target temperature. The face judgment method comprises the following steps:

(a) at least one visible light picture and at least one infrared light picture which are shot in the same shooting area are received.

(b) A current target temperature sensed for a temperature sensing region is received. Wherein, the temperature sensing area is located in the shooting area.

(c) Whether a human face exists in a corresponding block corresponding to the temperature sensing area in the visible light photo and the infrared photo is detected respectively.

(d) And when the face exists in the corresponding block, judging whether the current target temperature falls within a human body temperature range.

(e) And when the current target temperature is within the human body temperature range, judging the face detected in the corresponding block to be a living face.

The application of the invention has the following advantages. The false detection method can avoid the false guidance of various pictures with human faces, human faces displayed by a display element, human face masks or other human face forgery modes of non-living bodies, and the false judgment is that the living human faces are detected. In addition, only a single visible light photo and a single infrared photo are needed to recognize the living human face, so that the recognition result is provided quickly.

Drawings

In order to make the aforementioned and other objects, features, and advantages of the invention, as well as others which will become apparent, reference is made to the following description of the preferred embodiments of the invention in which:

fig. 1 is a functional block diagram of a face determination system according to an embodiment of the invention.

Fig. 2 is a schematic diagram of a photographing region and a temperature sensing region according to an embodiment of the invention.

Fig. 3 is a comparison diagram of the face recognition results of the face determination system 100 of the present invention in various application scenarios.

Fig. 4 is a flowchart of a face determination method according to an embodiment of the invention.

Wherein, the reference numbers:

100: the face determination system 110: visible light camera

120: infrared light camera 130: non-contact temperature sensing device

140: the processing element 141: face detection module

142: body temperature judging module 143: face recognition module

144: the prompt module 145: instruction execution module

201: shooting area 202: temperature sensing area

300: face judgment method

310-360: step (ii) of

Detailed Description

In the following description, reference is made to the accompanying drawings and detailed description, wherein changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention, as the description proceeds, and in part, while indicating preferred embodiments of the invention, is shown by the appended claims.

Referring to fig. 1, a functional block diagram of a face judgment system according to an embodiment of the invention is shown. The human face judgment system identifies the living human face by utilizing the visible light photo, the infrared light photo and the sensed current target temperature.

The face determination system 100 includes a visible light camera 110, an infrared light camera 120, a non-contact temperature sensing device 130, and a processing element 140. The non-contact temperature sensing device 130 may be an infrared thermometer (IR thermometer) or other type of non-contact temperature sensing device. The processing element 140 may be provided by a computer, server, or other type of electronic device. The processing element 140 can establish a connection with the visible light camera 110, the infrared light camera 120, and the non-contact temperature sensing device 130 by using a wired or wireless data transmission interface.

The visible light camera 110 takes at least one visible light picture. The infrared camera 120 takes at least one infrared photo. The visible light photo and the infrared light photo are obtained by the visible light camera 110 and the infrared light camera 120 respectively shooting the same shooting area at the same or similar time. In addition, in some embodiments of the present invention, the visible light and the infrared light may be irradiated to the shooting area, so that the visible light camera 110 and the infrared light camera 120 can take clearer pictures.

The non-contact temperature sensing device 130 senses a current target temperature for a temperature sensing area. Wherein the temperature sensing area (e.g., area 202 of fig. 2) falls within the photographing area (e.g., area 201 of fig. 2). In addition, the time sensed by the current target temperature is the same as or similar to the shooting time of the visible light picture and the infrared light picture. In some embodiments of the present invention, the visible light camera 110, the infrared light camera 120, and the non-contact temperature sensing device 130 can be further synchronized such that the capturing and sensing time is the same.

The processing unit 140 includes a face detection module 141 and a body temperature determination module 142. The face detection module 141 detects whether a face exists in a corresponding block corresponding to the temperature sensing area in the visible light photo and the infrared photo respectively. In some embodiments of the invention, the face detection module 141 may perform a face detection algorithm or a face recognition algorithm on the visible light photo and the infrared light photo to detect whether a face exists in a corresponding block of the corresponding temperature sensing area. In other embodiments of the present invention, the face detection module 141 may perform skin color detection on the visible light photo to detect whether there is a skin color block that may be regarded as a face in the corresponding block of the corresponding temperature sensing area. When the face detection module 141 determines that a face exists in the corresponding block, the body temperature determination module 142 determines whether the current target temperature falls within a human body temperature range.

Then, when the body temperature determination module 142 determines that the current target temperature falls within the human body temperature range, the processing element 140 determines that the face detected in the corresponding block is a live face. Therefore, the false detection of the living human face can be avoided by being misled by various pictures with the human face, the human face displayed by the display element, the human face mask or other human face forgery modes of non-living bodies. In addition, only a single visible light photo and a single infrared photo are needed to recognize the living human face, so that the recognition result is provided quickly. In addition, referring to fig. 3, it is a comparison diagram of the face recognition result when the face determination system 100 performs face recognition in various application scenarios. Wherein, o represents that the face of the corresponding input source is detected, and X represents that the face of the corresponding input source is not detected. When a color photograph or a screen of a smart phone/computer is used to display a human face, the infrared camera 120 and the non-contact temperature sensor 130 of the human face determination system 100 do not detect the displayed human face, and therefore are not misled by the human face displayed in the above manner. In addition, when the infrared photo is used to display a human face, the visible light camera 110 of the human face determination system 100 will not detect the displayed human face after being matched with the skin color detection function, and the non-contact temperature sensing device 130 will not detect a block that can be regarded as a living human face, so that the block will not be misled by the human face displayed by the infrared photo. In addition, when the face of a person is counterfeited by a mask or a dummy, the face determination system 100 can still use the non-contact temperature sensing device 130, and the counterfeited face is not detected, so that the person can be correctly determined as a non-living face. In other words, the face determination system 100 of the present invention is not easily misled by a common face forgery manner, and thus has a high correct recognition rate.

In some embodiments of the present invention, the processing element 140 further comprises a face recognition module 143 and a prompt module 144. When the processing element 140 determines that the face detected in the corresponding block is a live face, the face recognition module 143 may perform face recognition on the face detected in the corresponding block. The face recognition module 143 can perform face recognition by using at least one of a visible light photo and an infrared photo. Therefore, the face identification method can avoid the face identification reliability by adopting various pictures with faces, faces displayed by the display element, face masks or other non-living face counterfeiting modes through a face identification mechanism.

In addition, when it is determined that the face detected in the corresponding block is not a live face, the prompt module 144 may generate a prompt signal to prompt the position of the temperature sensing area sensed by the non-contact temperature sensing device 130. Wherein, the prompting can be carried out by voice signals, light signals, text messages or other types of prompting signals. Therefore, the misjudgment caused by the fact that the user does not place the face in the correct temperature sensing area during identification can be avoided.

In other embodiments of the present invention, the processing element 140 may further comprise an instruction execution module 145. Thus, when the face detected in the corresponding block is determined to be a live face, the instruction execution module 145 may start executing a predetermined instruction. For example, when the face determination system 100 is applied to an advertisement displaying machine, the instruction execution module 145 may start to execute a preset instruction for displaying an advertisement when the face detected in the corresponding block is determined to be a live face. However, in other embodiments, the instruction execution module 145 may execute other preset instructions when determining that the living human face is detected, and is not limited to the scheme disclosed in the present invention. Therefore, the number of times of executing instructions unnecessarily due to the detection of the non-living human face can be reduced.

In some embodiments of the present invention, the face determination system further comprises a beam splitter. Thus, the beam splitter can split the light from the same shooting area to the visible camera 110 and the infrared camera 120. In this way, the visible light camera 110 and the infrared light camera 120 can shoot from the same shooting area through the light splitting function of the beam splitter.

In other embodiments of the present invention, the visible light camera 110 and the infrared light camera 120 can be implemented using the same photosensitive element. The visible light camera 110 and the infrared light camera 120 may respectively include a visible light filter and an infrared light filter. Therefore, the same photosensitive element can be used to take a visible light picture and an infrared light picture through the visible light filter and the infrared light filter, respectively. Therefore, the required number of photosensitive elements can be further reduced, and the cost is reduced.

Fig. 4 is a flowchart of a face determination method according to an embodiment of the invention. In the face judgment method, the living body face is judged by utilizing a visible light photo, an infrared light photo and the sensed current target temperature. The face determination method can be implemented by a computer program. The computer program can be stored in a computer readable recording medium, so that the computer can read the recording medium and execute the face judgment method. The computer readable recording medium can be a readable memory, a flash memory, a floppy disk, a hard disk, an optical disk, a portable disk, a magnetic tape, a database accessible by a network, or a computer readable recording medium with the same functions as those of the computer readable recording medium easily understood by those skilled in the art.

The face determination method 300 comprises the following steps:

in step 310, at least one visible light photo and at least one infrared photo of the same shooting area are received.

In step 320, a current target temperature sensed for a temperature sensing area is received. Wherein, the temperature sensing area is located in the shooting area. In addition, the visible light photograph, the infrared light photograph and the current target temperature are taken or sensed at the same or similar time.

In step 330, whether a human face exists in a corresponding block corresponding to the temperature sensing area in the visible light photo and the infrared light photo is detected respectively. When a human face does not exist in at least one of the visible light photo and the infrared light photo corresponding to the block, the next set of visible light photo and infrared light photo can be received again (step 310). In some embodiments of the present invention, the detection in step 330 may be performed by performing a face detection algorithm or a face recognition algorithm on the visible light photograph and the infrared light photograph. In other embodiments of the present invention, the detection in step 330 can be achieved by performing skin color detection on the visible light photo to detect whether there is a skin color block that may be regarded as a human face in the corresponding block of the corresponding temperature sensing area.

In step 340, when it is determined that the face exists in the corresponding block, it is determined whether the current target temperature falls within a human body temperature range.

In step 350, when the current target temperature falls within the human body temperature range, the face detected in the corresponding block of the corresponding temperature sensing area is determined to be a live face. Therefore, the false detection of the living human face can be avoided by being misled by various pictures with the human face, the human face displayed by the display element, the human face mask or other human face forgery modes of non-living bodies. In addition, only a single visible light photo and a single infrared photo are needed to recognize the living human face, so that the recognition result is provided quickly.

In step 360, when the current target temperature is outside the human body temperature range, the human face detected in the corresponding block of the corresponding temperature sensing area is determined to be a non-living human face.

In some embodiments of the present invention, when the face detected in the corresponding block of the corresponding temperature sensing region is determined to be a living face (step 350), face recognition may be further performed on the face detected in the corresponding block. Therefore, the face identification method can avoid the face identification reliability by adopting various pictures with faces, faces displayed by the display element, face masks or other non-living face counterfeiting modes through a face identification mechanism.

In addition, when the human face detected in the corresponding block corresponding to the temperature sensing region is determined to be a non-living human face (step 360), a prompt signal can be generated to prompt the position of the temperature sensing region. Wherein, the prompting can be carried out by voice signals, light signals, text messages or other types of prompting signals. Therefore, the misjudgment caused by the fact that the user does not place the face in the correct temperature sensing area during identification can be avoided.

In other embodiments of the present invention, when the face detected in the corresponding block corresponding to the temperature sensing region is determined to be a live face (step 350), a predetermined command may be executed. For example, when the present invention is applied to an advertisement displaying machine, the advertisement displaying machine may start to execute a preset instruction for displaying an advertisement when it is determined that a face detected in a corresponding block is a live face. However, in other embodiments, other preset instructions may be executed when it is determined that the living human face is detected, and the present invention is not limited to the technical solution of the present invention. Therefore, the number of times of executing instructions unnecessarily due to the detection of the non-living human face can be reduced.

In addition, in some embodiments of the present invention, the light from the photographing region can be split into a visible light camera and an infrared light camera through a splitting mirror, and a visible light photo and an infrared light photo are captured for receiving in step 310. Therefore, the visible light camera and the infrared light camera can easily take the visible light picture and the infrared light picture from the same shooting area.

In other embodiments of the present invention, the same photosensitive element may be used to take a visible light picture and an infrared light picture through a visible light filter and an infrared light filter, respectively. Therefore, the number of photosensitive elements required by the application of the invention can be further reduced, and the cost is reduced.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. A face determination system, comprising:

a visible light camera for shooting at least one visible light picture;

the infrared camera shoots at least one infrared photo, wherein the visible photo and the infrared photo are respectively shot in the same shooting area by the visible camera and the infrared camera;

a non-contact temperature sensing device for sensing a current target temperature for a temperature sensing area, wherein the temperature sensing area is located in the shooting area; and

a processing element connected to the visible light camera, the infrared light camera and the non-contact temperature sensing device, wherein the processing element comprises:

a face detection module, which detects whether a face exists in a corresponding block corresponding to the temperature sensing area in the visible light photo and the infrared photo respectively; and

a body temperature judging module, for judging whether the current target temperature is within a human body temperature range when the corresponding block has a human face, wherein the processing element judges that the human face detected in the corresponding block is a living human face when the current target temperature is within the human body temperature range.

2. The face determination system of claim 1, further comprising:

and the visible light camera and the infrared light camera shoot from the same shooting area through the light splitting function of the spectroscope.

3. The face judgment system according to claim 1, wherein:

the visible light camera comprises a visible light filter;

the infrared camera comprises an infrared filter; and

the visible light camera and the infrared light camera use the same photosensitive element, respectively shoot the visible light picture and the infrared light picture through the visible light filter and the infrared light filter thereof.

4. The face determination system of claim 1, wherein the processing element further comprises:

a face recognition module for performing face recognition on the face detected in the corresponding block when the face detected in the corresponding block is determined to be a living face; and

and the prompting module generates a prompting signal to prompt the position of the temperature sensing area when the face detected in the corresponding block is judged not to be a living body face.

5. The face determination system of claim 1, wherein the processing element further comprises:

and the instruction execution module starts to execute a preset instruction when the face detected in the corresponding block is judged to be the living face.

6. A face judgment method is characterized by comprising the following steps:

(a) receiving at least one visible light picture and at least one infrared light picture which are shot in the same shooting area;

(b) receiving a current target temperature sensed by a temperature sensing area, wherein the temperature sensing area is located in the shooting area;

(c) respectively detecting whether a human face exists in a corresponding block corresponding to the temperature sensing area in the visible light photo and the infrared photo;

(d) when the corresponding block is judged to have the face, judging whether the current target temperature is within a human body temperature range; and

(e) when the current target temperature is within the human body temperature range, the face detected in the corresponding block is determined to be a live face.

7. The method as claimed in claim 6, wherein the visible light photo and the infrared photo are transmitted through a beam splitter to split the light from the photographing area into a visible light camera and an infrared camera for photographing respectively.

8. The method as claimed in claim 6, wherein the visible light photograph and the infrared light photograph are taken by a same photo-sensor through a visible light filter and an infrared light filter, respectively.

9. The face judgment method of claim 6, further comprising:

when the face detected in the corresponding block is judged to be a living face, carrying out face identification on the face detected in the corresponding block; and

when the face detected in the corresponding block is judged not to be a living body face, a prompt signal is generated to prompt the position of the temperature sensing area.

10. The face judgment method of claim 6, further comprising:

and when the face detected in the corresponding block is determined to be a living face, starting to execute a preset instruction.