JP4840978B2 - IMAGING DEVICE, ITS CONTROL METHOD, PROGRAM, AND STORAGE MEDIUM - Google Patents

Description

  The present invention relates to a method for displaying a face detection frame at the time of personal authentication in an imaging apparatus with a personal authentication function.

  In an imaging apparatus with a personal authentication function, a subject is photographed by a camera, a human face is detected from the photographed image, and feature information for identifying the person to be authenticated is extracted from the face image. Then, the extracted feature information is compared with the registrant's feature information registered in the database in advance, the degree of similarity is judged, and whether or not the person to be authenticated is a registrant is authenticated based on the judgment result. ing.

  Here, the feature data obtained from the image includes the shooting conditions (background, lighting conditions, distance, angle, etc.), changes in posture, changes in facial expression, etc. at the time of shooting. Affected by differences in conditions. For this reason, even feature information obtained from the same person does not always match, and the similarity between the feature information at the time of registration and the feature information at the time of authentication is determined as a threshold. For this reason, there is an authentication error that determines that an unauthenticated person to be registered is a registrant due to a difference in conditions at the time of imaging, or determines that the person to be authenticated is not a registrant even though the person to be authenticated is a registrant. May occur.

As described above, when extracting facial feature data peculiar to the person, various parameters such as presence / absence of glasses, change in facial expression, posture, lighting environment, and the like are important collation factors. Therefore, in order to identify the person, the reliability at the time of personal authentication is higher when the feature data including as many parameters as possible is registered.
JP 2005-071125 A

  As described above, in an imaging apparatus with a personal authentication function, a person who is easy to be personally authenticated and a person who is difficult to be personally authenticated are generated due to the difference in the amount of data stored in the database. A person who is difficult to be personally authenticated often fails in personal authentication when shooting, and often misses the opportunity of shooting.

  If a person with low reliability is detected, it is possible that the amount of data stored in the database is not sufficient. If the user notices this and increases the amount of the person's data, the user's authentication failure and missed shooting opportunities can be reduced.

  However, it is impossible for the user to know all of how much data is stored, and if the user checks each time, it will be time-consuming and very inconvenient. .

  Accordingly, the present invention has been made in view of the above-described problems, and the object of the present invention is whether the amount of data stored in the database is sufficient for each user in an imaging apparatus with a personal authentication function. It is to be able to easily determine whether or not.

  In order to solve the above-described problems and achieve the object, an imaging apparatus according to the present invention includes a display unit that displays a captured image, a face detection unit that detects a human face from the captured image, Based on the database storing the feature information of the face of a specific person, the image of the face of the person detected by the face detection means, and the feature information of the face of the specific person stored in the database, Based on the reliability calculated by determining whether or not the person detected by the face detection means is a specific person and calculating the reliability thereof, the reliability calculated by the reliability calculation means, Control means for changing a display method of a frame to be displayed on the face of the person displayed on the display means.

  An image pickup apparatus control method according to the present invention is a method for controlling an image pickup apparatus comprising: display means for displaying a photographed image; and a database storing feature information of a face of a specific person. Based on a face detection step of detecting a person's face from the photographed image, a person's face image detected in the face detection step, and feature information of a specific person's face stored in the database Determining whether or not the person detected in the face detection step is a specific person and calculating the reliability thereof, and based on the reliability calculated in the reliability calculation step And a control step of changing a display method of a frame displayed on the face of the person displayed on the display means.

  A program according to the present invention causes a computer to execute the above control method.

  A storage medium according to the present invention stores the above program.

  According to the present invention, in an imaging apparatus with a personal authentication function, it is possible to easily determine for each user whether or not the amount of data stored in the database is sufficient.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing a schematic configuration of an imaging apparatus according to an embodiment of the present invention.

  In FIG. 1, a light beam representing a subject image is collected by a lens system 1 and is incident on an image sensor 2 such as a CCD. The video signal output from the image sensor 2 is subjected to analog signal processing such as correlated double sampling in the analog signal processing circuit 3. The video signal output from the analog signal processing circuit 3 is converted into digital data by the A / D conversion circuit 4 and input to the control circuit 12 and the digital signal processing circuit 5. The digital signal processing circuit 5 performs digital signal processing such as gamma correction and white balance processing. The video signal output from the digital signal processing circuit 5 is sent to the display device 9 via the memory 6. Then, a subject image is displayed on the display screen of the display device 9.

  The video signal output from the digital signal processing circuit 5 is also input to the face detection processing circuit 10. In the face detection processing circuit 10, a face image area is detected from the input image signal. Further, the detected face image is sent to the personal authentication processing circuit 11, and personal authentication is performed using the database 13 in which personal face feature data is registered. The personal authentication processing circuit 11 also has a function of evaluating the reliability of the result of personal authentication. The reliability referred to here is a value indicating the accuracy of authentication, and is calculated by comparing the input signal with the feature data in the database. For example, the greater the number of matching samples, the higher the reliability. That is, even if the degree of coincidence is high, if the number of samples is small, the reliability is not high. As used herein, the term “match” includes not only a perfect match as a result of comparison but also a value whose error is within a predetermined range.

  In a normal shooting operation without personal authentication, when the shutter button is pressed, the subject is imaged in the same manner as described above, and image data representing the subject image is obtained. The image data is given from the digital signal processing circuit 5 to the memory 6 and temporarily stored. The image data is read from the memory 6 and recorded on the memory card 8 by the recording control circuit 7.

  Various techniques are known as techniques for detecting a face performed by the face detection processing circuit 10. For example, there is a method using learning represented by a neural network. In addition, there is a technique for identifying parts having physical shape features such as eyes, nose, mouth, and facial contour from image data using template matching. In addition, there is a technique that detects a feature amount of image data such as skin color or eye shape and uses statistical analysis (for example, Japanese Patent Laid-Open Nos. 10-232934 and 2000-48184). reference). In the present embodiment, face identification processing is performed by detecting a pair of eyes (both eyes), nose, mouth, and face outline, and determining a person's face from their relative positions.

  Further, the personal authentication processing circuit 11 performs personal authentication by pattern matching or the like based on personal face feature information registered in the database 13.

  Next, the operation of personal authentication in the imaging apparatus of the present embodiment will be described with reference to the flowchart shown in FIG.

  Before performing the operation shown in FIG. 2, a person to be registered is photographed in advance with this imaging apparatus, and the facial feature data of the person is registered in the database 13. Registration in the database 13 may be performed by connecting a personal computer or the like to the imaging apparatus and inputting registration information from the outside to the imaging apparatus.

  Further, before starting the flow of FIG. 2, the person to be authenticated is photographed by this imaging apparatus and a face image is captured.

  First, in step S11, face detection processing is performed from image data obtained by photographing the person to be authenticated. If a face is detected, the process proceeds to step S12 to perform personal authentication processing. If no face is detected, the personal authentication process is terminated and the normal shooting mode is restored. In step S12, personal authentication is performed based on the face information detected in step S11. Next, proceeding to step S13, the reliability when personal authentication is performed is calculated. Then, based on the reliability data calculated in step S13, in step S14, the display of the face detection frame is changed according to the reliability. At this time, the image of the person to be authenticated and the face detection frame are displayed on the display device 9.

  FIG. 3 is a diagram illustrating an example of a face detection frame display method according to the reliability.

  Here, depending on the reliability at the time of personal authentication, for example, the display shape of the face detection frame is □ when the reliability is 80 to 100%, ◯ when it is 50 to 80%, and △ when it is 20 to 50%. When 0 to 20%, the example of changing the display of the face detection frame is shown as x.

  In addition, it is conceivable to change the color of the face detection frame to green, blue, yellow, red, or to increase the size as the reliability increases.

  Moreover, it is also conceivable to display by changing the thickness of the frame, the display of lines, and the like as in pattern 1 and pattern 2.

  FIG. 3 shown here only shows an example of the concept of changing the display of the face detection frame according to the reliability, and the color and design of the face detection frame can be considered other than this. A plurality of these patterns such as design and color may be combined.

  Furthermore, when the reliability at the time of personal authentication calculated in step S13 is low, a warning is given to the user to supplement the data stored in the database in step S15.

  FIG. 4 is a diagram illustrating a display example of a face detection frame when the reliability at the time of personal authentication is low.

  FIG. 4A shows the display state when the reliability is high to some extent, and only the face detection frame is displayed. FIG. 4B shows a display state when the reliability is low. In addition to the display of the face detection frame, a warning display such as “Please add information to the database” is also performed. Here, this warning display method is an example for prompting the user to add information to the database. In addition to such a display, for example, a warning sound or a detection frame blinks. Conceivable.

  By providing the above functions, the user can easily check how much data is stored in the database, and the personal authentication has failed, giving him the opportunity to shoot. Missing can be reduced.

  Furthermore, the effect of this function can be reflected in the composition at the time of shooting. Since the accuracy of personal authentication changes depending on the size of the face, by changing the display of the face detection frame according to the reliability, how big the face can be photographed can be used for accurate personal authentication. The user can grasp at a glance. Thereby, it can be easily understood to what extent the face in the shooting screen is enlarged to facilitate personal authentication. For example, if you know in advance how big your child's face in the shooting screen should be to ensure that personal authentication will not fail, you will have a chance to shoot because personal authentication failed at the athletic meet goal scene, etc. The situation of missing can also be prevented.

(Other embodiments)
The object of each embodiment is also achieved by the following method. That is, a storage medium (or recording medium) in which a program code of software that realizes the functions of the above-described embodiments is recorded is supplied to the system or apparatus. Then, the computer (or CPU or MPU) of the system or apparatus reads and executes the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but the present invention includes the following cases. That is, based on the instruction of the program code, an operating system (OS) running on the computer performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

  Furthermore, the following cases are also included in the present invention. That is, the program code read from the storage medium is written in a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer. Thereafter, based on the instruction of the program code, the CPU or the like provided in the function expansion card or function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

  When the present invention is applied to the above storage medium, the storage medium stores program codes corresponding to the procedure described above.

1 is a block diagram illustrating a schematic configuration of an imaging apparatus according to an embodiment of the present invention. It is a flowchart which shows the personal authentication process of the imaging device of one Embodiment. It is the figure which showed the example of the face detection frame display method according to reliability. It is a figure which shows an example of the face detection frame display at the time of personal authentication.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens system 2 Image pick-up element 3 Analog signal processing circuit 4 A / D converter 5 Digital signal processing circuit 6 Memory 7 Recording control circuit 8 Memory card 9 Display apparatus 10 Face detection processing circuit 11 Personal authentication processing circuit 12 Control circuit

Claims (8)

Display means for displaying the captured image;
Face detection means for detecting a human face from the captured image;
A database storing facial information of a specific person,
The person detected by the face detection means is a specific person based on the face image of the person detected by the face detection means and the facial feature information of the specific person stored in the database. Reliability calculation means for determining whether or not and calculating the reliability,
Control means for changing a display method of a frame to be displayed on the face of the person displayed on the display means based on the reliability calculated by the reliability calculation means;
An imaging apparatus comprising:   The imaging apparatus according to claim 1, wherein the control unit changes at least one of a shape, a color, a pattern, a size, and a thickness of a frame line based on the reliability.   The imaging apparatus according to claim 1, wherein when the reliability is low, a warning is given to supplement the information in the database. A method for controlling an imaging apparatus comprising display means for displaying a captured image and a database storing facial feature information of a specific person,
A face detection step of detecting a person's face from the captured image;
The person detected in the face detection step based on the face image of the person detected in the face detection step and the feature information of the face of the specific person stored in the database is a specific person. A reliability calculation step for determining whether or not and calculating the reliability,
A control step of changing a display method of a frame to be displayed on the face of the person displayed on the display unit based on the reliability calculated in the reliability calculation step;
An image pickup apparatus control method comprising:   5. The control of the imaging apparatus according to claim 4, wherein in the control step, at least one of a shape, a color, a pattern, a size, and a thickness of the frame line is changed based on the reliability. Method.   5. The method of controlling an imaging apparatus according to claim 4, further comprising a warning step of warning the information in the database to be supplemented when the reliability is low.   A program for causing a computer to execute the control method according to any one of claims 4 to 6.   A computer-readable storage medium storing the program according to claim 7.

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