Facial imaging method

Abstract

The present invention relates to a facial imaging method comprising the steps of: determining a reference image which serves as the reference of the distance and angle at which a face is imaged; detecting a feature point of the face from the reference image; generating a guide for the user's follow-up imaging by using the detected feature point; displaying the guide on a live view screen in the follow-up imaging process; and conducting imaging after adjusting the distance and angle of imaging by using the guide. Three or more feature points are detected from the left eye, the right eye, the nose, the mouth, the eyebrows, the periphery of the mouth, mouth wrinkles, the chin line, the ears, and the cheekbones located on the face. According to the present invention, the guide generated by applying feature points derived from the reference image is used such that, in the process of imaging the face of the user or another person, the face can be repeatedly imaged at the distance and angle of imaging substantially identical to those of the reference image. The present invention is advantageous in that, by conducting the follow-up imaging in such a method, the individual's facial change can be accurately recorded, and changes occurring on the facial skin can be analyzed and tracked consistently.

Description

How to take a picture of your face

[0001] The present invention relates to a method for photographing a face by inducing an angle and distance for photographing the face, and more particularly, to a method for photographing a face that includes a process of guiding so that the face can be repeatedly photographed under conditions almost identical to the angle and distance of a previously photographed image.

[0002] Since the face is generally a three-dimensional shape, the position of the camera lens used to capture the face can make a big difference in the resulting image.

[0003] Fig. 11 is a drawing showing the distance between the camera and the face, Fig. 12 is a drawing showing the angle between the camera and the face, and Fig. 13 is a drawing comparing the shooting results according to the difference in distance and angle between the camera and the face.

[0004] As shown, when the distance and angle between the camera and the face are adjusted differently from d1 to d4 and from θ1 to θ2, the shape of the captured face photo is completely different. Considering (a) as a reference, in the image (b), the face is positioned higher than the camera, so the lower part of the face is large. In the case of (c), the camera is positioned higher than the face, so the upper part of the head is captured large. In the case of (d), the camera and the face are at the same height, but the distance is farther, so the face appears small, and the resolution is reduced due to the long distance. In this way, problems arise in which the impression of the face, age estimation, information on the face surface, and user preference change depending on the shooting distance and angle.

[0005] Meanwhile, there's a growing demand for capturing faces from the same angle and location for various purposes. For example, when performing facial recognition for security and access control purposes, matching the angle and distance of the face can improve recognition efficiency. Similarly, when capturing faces for purposes like assessing the progress of skin treatments, matching the angle and distance facilitates comparison.

[0006] Recently, technologies using AI to compensate for differences in shooting angle and distance have been developed. However, there are limitations to increasing accuracy. Furthermore, increasing accuracy requires increasing AI model complexity, which not only increases capacity but also requires significant time. Therefore, when capturing a face, maintaining the same shooting angle and distance as possible reduces costs compared to using AI for compensation. Even when applying AI, lightweight algorithms can provide rapid compensation.

[0007] A device (Korean Utility Model Registration No. 20-0189932) was developed to photograph the face from the same distance and angle to accurately compare skin treatment processes, but it has the disadvantage of limited utility and requiring installation space.

[0008] The present invention is intended to solve the problems of the prior art described above, and its purpose is to provide a method for photographing a face under conditions that are almost identical to the angle and distance of a previously photographed image.

[0009] In order to achieve the above object, the present invention provides a method for photographing a face, comprising: a step of determining a reference image that serves as a reference for a distance and angle for photographing a face; a step of detecting facial feature points from the reference image; a step of generating a guide for a user's subsequent photographing using the detected feature points; a step of displaying the guide on a live view screen during the subsequent photographing process; and a step of adjusting the photographing distance and angle and photographing using the guide. The method is characterized in that the feature points are three or more detected from a left eye, a right eye, a nose, a mouth, an eyebrow, a corner of the mouth, nasolabial folds, a jawline, an ear, and a cheekbone located within the face.

[0010] At this time, three feature points are detected, and the feature points may form a triangle, and may be selected from different parts among the left eye, right eye, nose, mouth, eyebrow, corner of the mouth, nasolabial folds, jawline, ear, and cheekbone.

[0011] The guide displayed on the live view screen may be a triangle connecting three feature points, and the live view screen may also display guidance text about the location of the feature points together with the guide.

[0012] The above features may include at least features for the position of the eyes, features for the position of the nose, and features for the position of the mouth.

[0013] The above feature points may include at least two feature points for the left end of the left eye and the right end of the right eye, two feature points for the horizontal ends of the nose, and two feature points for the horizontal ends of the mouth.

[0014] The above feature points may include at least four feature points for each horizontal end of each eye, two feature points for each horizontal end of the nose, and two feature points for each horizontal end of the mouth.

[0015] The above guide may be in the form of indicating the areas of the eyes, nose and mouth.

[0016] The above guide may be in the form of dividing the screen into a predetermined number of grids and displaying the grids that include feature points.

[0017] The grid can be divided into six grids of a size and number sufficient to be displayed separately, each grid including two feature points for the left end of the left eye and the right end of the right eye, two feature points for the horizontal ends of the nose, and two feature points for the horizontal ends of the mouth.

[0018] The grid can be divided into eight grids of a size and number sufficient to be displayed separately, each grid including four feature points for each horizontal end of each eye, two feature points for each horizontal end of the nose, and two feature points for each horizontal end of the mouth.

[0019] In order to compare the similarity between the reference image and the subsequent captured images, the following similarity index D is calculated for each image,

[0020]

[0021] (Here, p is the number of feature points, (x p , y p ) are the coordinates of the feature points, (g n,x , g n,y ) is the coordinate of the grid intersection closest to the feature point)

[0022] Similarity can also be measured by comparing the values ​​of D produced from each image.

[0023] At this time, if the difference in D calculated from each image is less than a predetermined value, it can be configured to guide re-shooting.

[0024] The present invention, configured as described above, uses a guide generated by applying feature points derived from a reference image, so that the face can be repeatedly photographed at a shooting distance and angle almost identical to that of the reference image during the process of photographing the face of oneself or another person.

[0025] By conducting follow-up photography in this way, it is possible to accurately record changes in an individual's face and enable consistent analysis and tracking of changes occurring in the facial skin.

[0026] Figure 1 is a flowchart for explaining a face photographing method according to the present invention.

[0027] FIG. 2 is a drawing for explaining feature point detection applied in a face photographing method according to an embodiment of the present invention.

[0028] Figure 3 is a first example of detecting three feature points applied in a face photographing method according to one embodiment of the present invention.

[0029] FIG. 4 is a second example of detecting three feature points applied in a face photographing method according to one embodiment of the present invention.

[0030] FIG. 5 is a third example of detecting three feature points applied to a side face photograph in a face photographing method according to one embodiment of the present invention.

[0031] FIG. 6 is a drawing illustrating a case in which a guide for the positions of eyes, nose, and mouth is generated in a face photographing method according to another embodiment of the present invention.

[0032] FIG. 7 is a drawing for explaining a method for photographing a face according to another embodiment of the present invention, in which a guide is provided as a guide for photographing.

[0033] FIG. 8 is a drawing for explaining another form of providing a guide for shooting in a face shooting method according to another embodiment of the present invention.

[0034] FIG. 9 illustrates a process of generating a guide in a face photographing method according to another embodiment of the present invention.

[0035] FIG. 10 is a drawing for explaining a process of quantifying the similarity between images in a face photographing method according to the present invention.

[0036] Figure 11 is a drawing showing the distance between the camera and the face.

[0037] Figure 12 is a drawing showing the angle between the camera and the face.

[0038] Figure 13 is a drawing comparing the shooting results according to the difference in distance and angle between the camera and the face.

[0039] An embodiment of the present invention is described in detail with reference to the attached drawings.

[0040] However, the embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. The shapes and sizes of elements in the drawings may be exaggerated for clearer explanation, and elements indicated by the same symbols in the drawings are the same elements.

[0041] Throughout the specification, when a part is said to be "connected" to another part, this includes not only the cases where it is "directly connected" but also the cases where it is "electrically connected" with another element in between. Furthermore, when a part is said to "include" or "comprise" a component, this does not mean that it excludes other components, but rather that it can include or comprise other components, unless otherwise specifically stated.

[0042] Additionally, terms such as "first," "second," etc. are intended to distinguish one component from another and should not be construed as limiting the scope of the rights. For example, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

[0043] Figure 1 is a flowchart for explaining a face photographing method according to the present invention.

[0044] First, the face photographing method of this embodiment determines a reference image.

[0045] The reference image is an image that serves as a reference for the distance and angle from the camera presented in the face photographing method of this embodiment, and the purpose of the present invention is to perform new photographing under conditions as close as possible to the photographing distance and angle of the reference image.

[0046] At this time, the reference image may be an image captured immediately or previously by the photographing device performing the facial photographing method of the present embodiment, or an image captured previously by another photographing device. To this end, it is preferable that the photographing device performing the facial photographing method of the present embodiment be configured to receive and store images captured by another photographing device, either wired or wirelessly.

[0047] Next, feature points are detected from the reference image to derive the same shooting distance and angle as the reference image.

[0048] FIG. 2 is a drawing for explaining feature point detection applied in a face photographing method according to an embodiment of the present invention.

[0049] Feature point detection is a method of marking feature points (landmarks) at the same location on the face as a predetermined number of points, and as shown in the figure, a large number of feature points can be detected from the outline of the face and the eyes, nose, mouth, and lips.

[0050] The present invention detects feature points to derive the same shooting distance and angle, and specifically, since the minimum number of feature points for determining whether the distance between the camera and the face and the angles in the up, down, left, and right directions are the same is three, in this embodiment, three or more feature points are detected.

[0051] FIG. 3 is a first example of detecting three feature points applied in a face photographing method according to one embodiment of the present invention, and FIG. 4 is a second example of detecting three feature points applied in a face photographing method according to one embodiment of the present invention.

[0052] Since the same shooting distance and angle can be derived by extracting and comparing three feature points, the specific method of detecting three feature points can be applied in various ways. When detecting three feature points as in Fig. 3, it is easy to derive the same shooting distance and angle for a photo taken of the front of the face, and when detecting three feature points as in Fig. 4, it is easy to derive the same shooting distance and angle for a photo taken of the side of the face. A photo taken of the side of the face as in Fig. 4 is more advantageous for checking pores, etc.

[0053] FIG. 5 is a third example of detecting three feature points applied to a side face photograph in a face photographing method according to one embodiment of the present invention.

[0054] Meanwhile, the present invention is characterized in that it uses the detected feature points as a guide to induce the same shooting distance and angle, and for this purpose, it is preferable to detect and use feature points located on the face, and in particular, feature points detected from areas where the position of the face can be confirmed, such as both eyes, nose, and mouth, can be used, and specifically, it is preferable to use feature points detected from the left eye, right eye, nose, mouth, eyebrows, corners of the mouth, nasolabial folds, jawline, ears, cheekbones, etc. In the case of deriving feature points from the jawline and ears, it can be usefully applied in the process of shooting the side of the face, as shown in FIG. 4, and at this time, it may be necessary to consider the three-dimensional arrangement of the feature points rather than the two-dimensional arrangement depending on the arrangement and morphological features of the jawline and ears.

[0055] Furthermore, when detecting three feature points, it is preferable to detect three feature points forming a triangle so that they can be easily applied as a guide. In particular, it is preferable to detect three feature points selected one each from the left eye, right eye, nose, mouth, eyebrows, corners of the mouth, nasolabial folds, jawline, ears, and cheekbones. Such feature point detection can be performed using an artificial intelligence-based learning method.

[0056] And, using the feature points detected from the reference image, a guide for the user's follow-up shooting is generated, and the generated guide is displayed on the live view screen during the follow-up shooting process, and the user performs follow-up shooting similar to the shooting distance and angle of the reference image by adjusting the shooting distance and angle using the provided guide.

[0057] The Live View screen displays the current recording status during the facial image capture process. When the camera and display are integrated into a single device, such as a mobile phone or kiosk, the Live View screen typically appears on the device's display. When the camera and display are separate, the camera's Live View screen can be transmitted to the display via wired or wireless transmission.

[0058] The guide is intended to suggest conditions that are as close as possible to the shooting distance and angle of the reference image, and is generated using previously detected feature points. As previously discussed, since the feature points extracted during the feature point detection process correspond to one or very small pixels, it is preferable to generate and display guides in various ways so that the user can easily match the feature points, rather than displaying the feature points as they are in the live view. In this embodiment, the guide is provided by displaying a triangle connecting the feature points in the live view, as shown in the third of FIGS. 3 to 5. The form of the guide can be applied in various ways, and specifically, the feature points themselves can be applied, or the guide can be provided in the form of a line or polygonal surface connecting the feature points, or it can be in the form of a grid.

[0059] Guides generated in this way can be stored separately from the reference image, and user identification information, such as a user ID, can be assigned to store the reference image and guide for each user. In this case, during subsequent shooting, the saved guide can be retrieved and used by entering the user identification information, thereby eliminating the process of extracting guides by detecting feature points from the reference image.

[0060] Users can adjust the shooting distance and angle by aligning the guide displayed on the screen with the face position on the live view screen.

[0061] Along with displaying these triangles in the live view, text may also be displayed to guide the user to the body parts from which feature points were extracted. In Fig. 3, the user may be guided to align the ends of both eyes and the nose with the indicated triangles, while in Figs. 4 and 5, the user may be guided to align the ends of the left eye and the left end of the nose and mouth with the indicated triangles.

[0062] When taking a picture while aligning the user's eyes, nose, or mouth on the live view screen with the triangle indicated as a guide, an image taken at almost the same shooting distance and angle as the reference image can be obtained.

[0063] FIG. 6 is a drawing illustrating a case in which a guide for the positions of eyes, nose, and mouth is generated in a face photographing method according to another embodiment of the present invention.

[0064] In order to match the shooting distance and angle of the reference image, when detecting three or more feature points, feature points for the left and right eyes, nose, and mouth are detected as a method to provide the user with the positions of the eyes, nose, and mouth as a guide. Since the positions of these feature points are located horizontally in the upper, middle, and lower positions of the face, they can reflect the shooting distance and the shooting angles in the upper, lower, left, and right directions, and can display the positions of the eyes, nose, and mouth as a guide to the user. The minimum number of feature points to detect in order to display the positions of the eyes, nose, and mouth is six, and specifically, the left end of the left eye, the right end of the right eye, both ends of the nostrils, and both ends of the mouth can be detected as feature points.

[0065] In this embodiment, eight feature points are detected, one at each of the horizontal ends of the left eye, one at each of the horizontal ends of the right eye, one at each of the horizontal ends of the nostrils, and one at each of the horizontal ends of the mouth. This feature point detection can be performed using an artificial intelligence-based learning method.

[0066] And, using the feature points detected from the reference image, a guide for the user's follow-up shooting is generated, and the generated guide is displayed on the live view screen during the follow-up shooting process, and the user performs follow-up shooting similar to the shooting distance and angle of the reference image by adjusting the shooting distance and angle using the provided guide.

[0067] As previously explained, in this embodiment, a guide that localizes the positions of the eyes, nose, and mouth can be generated.

[0068] The guide is intended to present conditions that are as close as possible to the shooting distance and angle of the reference image, and as in this embodiment, the process of extracting a guide that zones the positions of the eyes, nose, and mouth can create an eye zone, a nose zone, and a mouth zone as guides based on feature points for the eyes, nose, and mouth, and can be confirmed in Fig. 3.

[0069] Therefore, in this embodiment, as shown, eight feature points are detected for both ends of the eyes, both ends of the nostrils, and both ends of the mouth, and the areas of both eyes, the area of ​​the nose, and the area of ​​the mouth are generated as guides.

[0070] In this embodiment, the guide can be provided to the user by overlaying it on the reference image before performing subsequent shooting according to the guide.

[0071] Users can review a reference image with a guide overlayed on it, select it, and save it, or create a new reference image by re-capturing the face. Furthermore, a process for modifying the guide overlayed on the reference image can be provided.

[0072] And during the user's subsequent shooting process, a guide is displayed on the live view screen for shooting, and the user adjusts the shooting distance and angle to align his or her eyes, nose, and mouth displayed in the live view with the guides indicating the eye, nose, and mouth areas to perform shooting.

[0073] FIG. 7 is a drawing for explaining a method for photographing a face according to another embodiment of the present invention, in which a guide is provided as a guide for photographing.

[0074] As explained above, when storing reference images and guides for each user by assigning user identification information, guides that zone the locations of the eyes, nose, and mouth can be displayed in the live view simply by entering user information.

[0075] At this time, the shooting distance and angle can be adjusted by aligning the guide displayed on the screen with the face position on the live view screen. As previously discussed, in this embodiment, the eye, nose, and mouth areas are extracted and presented as guides, and the user can adjust the shooting distance and angle by moving the face or camera position so that the guided eye, nose, and mouth areas on the live view screen are aligned.

[0076] When shooting with the eye, nose, and mouth areas marked as guides aligned on the live view screen, an image captured at almost the same shooting distance and angle as the reference image can be obtained.

[0077] FIG. 8 is a drawing for explaining another form of providing a guide for shooting in a face shooting method according to another embodiment of the present invention.

[0078] As shown, the cropped images of the eyes, nose, and mouth from the reference image, rather than the eye, nose, and mouth areas, can be displayed as overlays on the live view in an opaque or semi-transparent state.

[0079] Because people can express a wide range of facial expressions, differences in facial expressions can occur during the shooting process. Even if feature points are aligned, different expressions may be captured, leading to differences in shooting angles and other factors. However, overlaying a cropped image can prevent errors caused by facial expression differences by reflecting the facial expressions from the reference image.

[0080] As another embodiment of detecting feature points in a reference image to generate a guide for subsequent shooting for the user, a grid reflecting the feature points of the reference image can be generated as a guide.

[0081] The guide is intended to present conditions that are as close as possible to the shooting distance and angle of the reference image, and as in this embodiment, the process of extracting the guide using a grid can divide the screen into multiple grids and create a grid in which feature points for the eyes, nose, and mouth are located as a guide.

[0082] FIG. 9 illustrates a process of generating a guide in a face photographing method according to another embodiment of the present invention.

[0083] Since the feature points extracted during the feature point detection process correspond to single or very small pixels, providing the feature points themselves as guides makes them difficult for users to utilize. Therefore, in this embodiment, as shown, the screen is divided into grids of a predetermined size and number, and the grid containing the feature points is created as a guide. Specifically, a grid containing eight feature points can be displayed in red.

[0084] As the number of grids increases and their size decreases, the accuracy between the feature points and the guide grids increases, but it becomes difficult for the user to align the eyes, nose, and mouth of the guide with the live view. Therefore, the size and number of grids to be divided can be set differently depending on the required precision, and in this embodiment, it is preferable to divide them into a size that can display eight grids containing eight feature points. To this end, if the number of grids displayed as guides is smaller than the number of feature points detected in the feature point detection step, the number of grid divisions can be increased to generate the guide again.

[0085] In this embodiment, the guide can be provided to the user by overlaying it on the reference image before performing subsequent shooting according to the guide.

[0086] Users can review a reference image with a guide overlayed on it, select it, and save it, or create a new reference image by re-capturing the face. Furthermore, a process for modifying the guide overlayed on the reference image can be provided.

[0087] During the saving process, the reference image and guide can be saved separately, or the reference image and guide can be saved for each user by assigning user identification information, such as a user ID. In this case, during subsequent shooting, the saved guide can be retrieved and used by entering the user identification information, thereby eliminating the process of extracting guides by detecting feature points from the reference image.

[0088] And during the user's subsequent shooting process, a guide is displayed on the live view screen for shooting, and the user adjusts the shooting distance and angle so that the ends of his or her eyes, nose, and mouth shown in the live view are included in the guide with a grid including the ends of the eyes, nose, and mouth.

[0089] As explained above, if you store reference images and guides for each user by assigning user identification information, you can display a guide with a grid that includes the ends of the eyes, nose, and mouth in Live View simply by entering user information.

[0090] As described above, according to the face photographing method of the present invention using a guide generated by applying feature points derived from a reference image, the face can be repeatedly photographed at a shooting distance and angle almost identical to that of the reference image during the process of photographing the face of oneself or another person.

[0091] By conducting follow-up photography in this way, it is possible to accurately record changes in an individual's face and enable consistent analysis and tracking of changes occurring in the facial skin.

[0092] Furthermore, you can select a photo you like from among the photos of your face as a reference image and take a selfie at the same distance and angle.

[0093] Furthermore, the similarity between facial images in terms of shooting distance and angle can be evaluated numerically using a grid that reflects feature points.

[0094]

[0095] *Figure 10 is a drawing for explaining a process of quantifying the similarity between images in a face photographing method according to the present invention.

[0096] As shown, information about the location of a feature point can be quantified through the relationship between the feature point detected in the face image and the intersection of the grid closest to the feature point. (x p , y p ) are the coordinates of the feature points, and in this example, since 8 feature points were detected, p = 1~8. (g n,x , g n,y ) is the coordinate of the grid intersection closest to the feature point.

[0097] The similarity index D for judging similarity is calculated using the following formula, which reflects the sum of the distances between the eight feature points and the nearest grid intersection from each feature point.

[0098]

[0099] For each of the two images (reference image, follow-up image) for similarity comparison, a D value is calculated, and the closer the two D values ​​are, the more similar the shooting distance and angle of the facial images can be evaluated.

[0100] After the follow-up shooting is completed, the feature points are detected for the follow-up facial image, the D value is calculated for the grid, and compared with the D value for the reference image, if it deviates from a predetermined value, a re-shooting can be requested.

[0101] The present invention has been described above through preferred embodiments. However, the above-described embodiments are merely illustrative of the technical idea of ​​the present invention. Those skilled in the art will understand that various changes can be made without departing from the technical idea of ​​the present invention. Therefore, the scope of protection of the present invention should be interpreted not by specific embodiments, but by the matters described in the claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included within the scope of the rights of the present invention.

Claims

1. A step of determining a reference image that serves as a reference for the distance and angle at which the face is photographed; A step of detecting facial feature points from a reference image; A step of generating a guide for the user's follow-up shooting using the detected feature points; A step of displaying a guide on the live view screen during the subsequent shooting process; and It includes steps for adjusting the shooting distance and angle using a guide and shooting. A method for photographing a face, characterized in that the above-mentioned characteristic points are three or more detected from the left eye, right eye, nose, mouth, eyebrows, corners of the mouth, nasolabial folds, jawline, ears, and cheekbones located on the face.

2. In claim 1, A face photographing method characterized in that three feature points are detected and the feature points form a triangle.

3. In claim 2, A method for photographing a face, characterized in that the above-mentioned characteristic points are each selected from different parts among the left eye, right eye, nose, mouth, eyebrow, corner of the mouth, nasolabial folds, jawline, ear, and cheekbone.

4. In claim 2, A method for photographing a face, characterized in that the guide displayed on the live view screen is a triangle connecting three feature points.

5. In claim 4, A method for photographing a face, characterized in that a guide text is displayed on the live view screen along with the location of the feature point.

6. In claim 1, A method for photographing a face, characterized in that the above-mentioned feature points include at least feature points for the position of the eyes, feature points for the position of the nose, and feature points for the position of the mouth.

7. In claim 6, A facial photographing method characterized by including two feature points for the left end of the left eye and the right end of the right eye, two feature points for the horizontal ends of the nostrils, and two feature points for the horizontal ends of the mouth.

8. In claim 6, A method for photographing a face, characterized in that the above-mentioned feature points include at least four feature points for each of the horizontal ends of each eye, two feature points for each of the horizontal ends of the bridge of the nose, and two feature points for each of the horizontal ends of the mouth.

9. In claim 6, A method for photographing a face, characterized in that the above guide is in a form that indicates the areas of the eyes, nose, and mouth.

10. In claim 6, A method for photographing a face, characterized in that the above guide is in the form of dividing the screen into a predetermined number of grids and displaying the grids containing feature points.

11. In claim 10, A method for photographing a face, characterized in that the grid is divided into six grids of a size and number sufficient to be displayed separately, each grid including two feature points for the left end of the left eye and the right end of the right eye, two feature points for the horizontal ends of the nose, and two feature points for the horizontal ends of the mouth.

12. In claim 10, A method for photographing a face, characterized in that the grid is divided into eight grids, each of which includes four feature points for each horizontal end of each eye, two feature points for each horizontal end of the nose, and two feature points for each horizontal end of the mouth, and the grid is divided into eight grids of such a size and number that they can be displayed separately from each other.

13. In claim 10, In order to compare the similarity between the reference image and the subsequent captured images, the following similarity index D is calculated for each image, (Here, p is the number of feature points, (x p , y p ) are the coordinates of the feature points, (g n,x , g n,y ) is the coordinate of the grid intersection closest to the feature point) A facial photographing method characterized in that the similarity can be measured by comparing the values ​​of D produced from each image.

14. In claim 13, A facial photographing method characterized in that it guides re-photographing when the difference in D produced from each image is less than a predetermined value.

Images