JP7333196B2 - 3D head model creation system and 3D head model creation method - Google Patents

Description

The present invention is a technique for creating a three-dimensional model of the head from a plurality of images. More specifically, the present invention creates a three-dimensional model of the head by using a print sheet on which a plurality of characters are displayed. The present invention relates to a three-dimensional head model creation system and a three-dimensional head model creation method using the system.

Custom-made wigs are generally manufactured through processes such as taking a mold, forming a wig base, and implanting artificial hair. Of these, the molding process is an extremely important process that determines the comfort of use of the wig, and it can be said that the accuracy of the head measurement carried out for molding determines the quality of the wig.

Head measurement for taking a mold is a measurement that is performed to reproduce the shape of the subject's (client's) head. The shape of the head was reproduced by obtaining a formwork that was hardened. Alternatively, some used a laser measuring device to measure the subject's head.

However, the method using a heated resin-like object puts a burden on the subject, and the accuracy of the form varies depending on the manufacturer. Therefore, there was a problem that introduction and replacement were difficult.

Therefore, realization of a measurement method that does not use a laser measurement device and that does not impose a burden on the subject has been eagerly desired. Therefore, Patent Literature 1 proposes a technique for reproducing the head shape of a subject using an image.

JP 2016-003427 A

The technology disclosed in Patent Document 1 acquires a plurality of images after pasting a large number of feature points on the subject's head, and creates a three-dimensional model of the head from these images. No expensive equipment such as a laser measuring device is required. However, it takes time and effort to attach many feature points to the head, and some subjects may refuse to attach the feature points.

An object of the present invention is to solve the conventional problems, namely, without using an expensive device, without imposing a burden on the subject, and more accurately and easily as compared with the prior art. To provide a three-dimensional head model creating system capable of creating a three-dimensional model of the head and a three-dimensional head model creating method using the system.

The present invention focuses on the fact that a subject's head is covered with a printed sheet on which a plurality of characters are displayed, and a three-dimensional model is created using an image of the subject's head photographed in that state. This is an invention based on an idea that has never existed before.

A three-dimensional head model creation system of the present invention is a system for creating a three-dimensional model of the head based on an image of the head covered with a print sheet on which a plurality of characters are displayed, the system comprising image acquisition means and model creation means. Among these, the image acquisition means is means for acquiring a head image (an image in which the printing sheet is in close contact with the head), and the model creation means is a means for capturing images from multiple directions so as to cover the entire circumference of the head. This is means for creating a three-dimensional model of the head by performing spatial arithmetic processing on the head image. Note that some of the head images used by the model generating means contain scales with existing dimensions.

The three-dimensional head model creation system of the present invention may further include posture measurement means and warning means. The orientation measurement means measures the orientation of the image acquisition means, and the warning means notifies a warning when the difference in the horizontal shooting direction between the current shooting and the previous shooting exceeds the angle threshold. Here, the horizontal photographing direction is a direction obtained by projecting the photographing direction of the image acquisition means onto a horizontal plane.

The three-dimensional head model creation system of the present invention may further include posture guide means. The posture guidance means guides the shooting posture of the image acquisition means by transparently displaying the stereoscopic face model on the display section of the image acquisition means. Further, when the head image is acquired by the image acquiring means, the posture guiding means rotates the stereoscopic face model by a predetermined angle around the vertical axis and displays it in a transparent manner. In this case, if the posture of the image acquiring means is determined so that the direction of the stereoscopic face model and the direction of the head are matched, then the whole circumference of the head can be covered with a plurality of head images.

A method of creating a three-dimensional head model according to the present invention is a method of creating a three-dimensional head model based on a plurality of images of a subject's head covered with a print sheet on which a plurality of characters are displayed. The method includes a preparation step, an image acquisition step, and a model creation step. In the preparation step, the subject wears the print sheet on the head so as to cover the entire head and to be in close contact with the head. In the image acquisition step, the head on which the print sheet is attached is photographed while moving around the subject to acquire a plurality of head images. A three-dimensional model of the subject's head is created by performing spatial arithmetic processing on the image. Note that in the image acquisition step, some of the head images to be acquired are photographed so that the scale having the existing dimensions is included.

The three-dimensional head model creation method of the present invention can also be a method of attaching a printed sheet on which a newspaper surface is printed to the head in the preparation process.

The three-dimensional head model creation method of the present invention can also be a method of wearing a hat formed of a printed sheet in the preparation process.

The three-dimensional head model creation method of the present invention can also be a method of wearing an apron (or cape) formed of a printed sheet in addition to wearing the printed sheet on the head in the preparation process.

The three-dimensional head model creation system and the three-dimensional head model creation method of the present invention have the following effects.
(1) A three-dimensional model can be created easily and inexpensively by simply using a camera or the like (image acquisition means) without requiring an expensive device such as a laser measuring device.
(2) The burden on the subject can be significantly reduced as compared with the conventional method, since the print sheet is simply worn on the head.
(3) Since characters and the like displayed on the print sheet can be used as feature points, it is possible to create a three-dimensional model with higher accuracy than in the past.

(a) is a model diagram showing a situation in which images are taken from multiple directions so as to cover the entire circumference of the head using the image acquisition means, and (b) is a cap (hat) formed of a printed sheet in close contact with the head. Photographic diagram showing the situation. 1 is a block diagram showing the main configuration of a three-dimensional head model creation system of the present invention; FIG. FIG. 4 is a flowchart showing the main processing flow of the 3D head model creation system of the present invention; The photograph figure which shows a hat type printing sheet. (a) is a photographic view of the subject wearing the hat-shaped printing sheet taken from behind, and (b) is a photographic view of the subject wearing the hat-shaped printing sheet taken obliquely from the front. The model figure which shows an example of a scale. (a) is a photograph showing an apron-type printed sheet on which an English newspaper is printed, and (b) is a photograph of a subject wearing the apron-type printed sheet taken from the front. 4A and 4B are model diagrams for explaining a directional difference obtained by a horizontal shooting direction for two consecutive shots; FIG. A photographic view showing a three-dimensional face model transparently displayed on the liquid crystal display of a smartphone. FIG. 2 is a flowchart showing main steps of the method for creating a three-dimensional head model according to the present invention;

An example of the three-dimensional head model creation system and the three-dimensional head model creation method of the present invention will be described with reference to the drawings.

1. Overall Overview The present invention provides a three-dimensional model of the head (hereinafter referred to as " One of its features is to create a head 3D model. In order to create a 3D model of the head, as shown in FIG. 1(a), head images captured from multiple directions so as to cover the entire periphery of the head are used.

When acquiring the head image, as shown in FIG. 1B, the "printing sheet 200" is photographed in a state in which it is in close contact with the head. The printed sheet is a sheet-shaped sheet such as a newspaper sheet on which a large number of characters are printed. For example, a cap (hat) on which characters are printed as shown in FIG.

2. 3D Head Model Creation System The 3D head model creation system of the present invention will be described in detail with reference to the drawings. The method of creating a 3D head model of the present invention is a method of creating a 3D head model using the 3D head model creating system of the present invention. will be described, and then the three-dimensional head model creation method of the present invention will be described.

FIG. 2 is a block diagram showing the main configuration of the 3D head model creation system 100 of the present invention. As shown in this figure, the three-dimensional head model creation system 100 includes image acquisition means 101, model creation means 102, posture measurement means 103, warning means 104, posture guidance means 105, and head image storage. Means 106, output means 107 such as a display and a printer, etc. can also be included.

The image acquisition means 101 that constitutes the 3D head model creation system 100 can use a digital camera, a digital video camera, or the like, and it is particularly preferable to use a mobile terminal such as a smart phone or a tablet computer. Moreover, the model creating means 102, the warning means 104, and the attitude guiding means 105 can be manufactured as dedicated ones, or can be used as a general-purpose computer device. This computer device can be configured by a personal computer (PC), a tablet PC such as an iPad (registered trademark), a mobile terminal including a smart phone, or the like. A computer device includes a processor such as a CPU, memory such as a ROM and a RAM, and may further include input means such as a mouse and a keyboard, and a display. The orientation measurement unit 103 is a sensor that measures the photographing orientation of the image acquisition unit 101, and can use an angular velocity sensor, a geomagnetic sensor, or the like. If a portable terminal such as a smartphone or a tablet computer is used, the image acquisition means 101, the model creation means 102, the posture measurement means 103, the warning means 104, and the posture guidance means 105, which constitute the three-dimensional head model creation system 100, can be used. It is preferable that one mobile terminal can be provided with the above.

The head image storage means 106 can use a storage device of a general-purpose computer (for example, a smart phone, a tablet computer, etc.), or can be constructed in a database server. When building a database server, it can be placed on a local network (LAN: Local Area Network), or it can be a cloud server that stores via the Internet (that is, wireless communication).

Main processing of the three-dimensional head model creation system 100 will be described in detail below with reference to FIG. FIG. 3 is a flowchart showing the main processing flow of the 3D head model creation system 100 of the present invention. Note that in these flow diagrams, the middle column shows the action taken, the left column shows what the action requires, and the right column shows what results from the action.

As described above, the 3D head model creation system 100 creates a 3D head model based on a plurality of head images of the subject's head. This head image is taken with the print sheet 200 covering the subject's head and in a state in which the print sheet 200 is in close contact with the subject's head. The printing sheet 200 is a sheet on which a large number of characters (e.g., newspaper pages, magazine articles, etc.) are printed. The printed sheet can be used as the printing sheet 200. FIG.

In particular, considering the adhesion to the head, it is preferable to use a printing sheet 200 having characters printed on the surface of a hat (hereinafter referred to as "cap-type printing sheet 200C") as shown in FIG. This hat-shaped printed sheet 200C can be put on by a person, and has elasticity and stretchability like a so-called knit cap or mesh cap. Therefore, as shown in FIGS. 5(a) and 5(b), when the subject wears the hat-shaped print sheet 200C, it flexibly fits (fits) the shape of the head, that is, it adheres appropriately. .

Among the multiple head images used to create the 3D model of the head, it is necessary to include a (photographed) head image containing the scale 300 as shown in FIG. 5(b). This scale 300 has its main dimensions already set in advance, and can be used in the form of a card with different marks arranged at the four corners, for example, as shown in FIG. In the case of the scale 300 shown in this figure, the length of the long side and the length of the short side (or one of them), the length of the diagonal line, etc. may be set as the existing values.

The head image has been described as being captured with the printing sheet 200 attached to the subject's head (for example, wearing the hat-shaped printing sheet 200C). In addition to the above, it is also possible to photograph with a print sheet 200 (hereinafter referred to as "apron-type print sheet 200A") having characters printed on its surface such as an apron, cape, or apron attached. FIG. 7(a) shows an apron-type printing sheet 200A on which an English newspaper is printed, and FIG. 7(b) shows a subject wearing this apron-type printing sheet 200A. As will be described later, when the model creating means 102 creates a 3D model of the head, a plurality of head images are connected by using characters (or a group of characters) displayed on the print sheet 200 as feature points. Therefore, when the apron-type printing sheet 200A is included in the image in addition to the hat-type printing sheet 200C, it becomes easier to extract more appropriate feature points.

A print sheet 200 (for example, a hat-type print sheet 200C) is attached to the subject's head (or an apron-type print sheet 200A is additionally attached), and when the scale 300 is placed at an appropriate position, the photographer can Acquire head images. Specifically, the image acquisition means 101 is prepared, that is, the photographer arranges the image acquisition means 101 at a predetermined position and posture (Step 10 in FIG. 3), and acquires a head image (Step 40 in FIG. 3). Note that when the photographer places the image acquisition unit 101 in a predetermined posture, the horizontal shooting direction of the image acquisition unit 101 is measured by the posture measurement unit 103 (Step 20 in FIG. 3). Here, the horizontal imaging direction is a direction obtained by projecting the imaging direction of the image acquisition means 101 onto a horizontal plane.

When the first (first) head image is acquired, the photographer arranges the image acquisition means 101 at a predetermined position and posture so that the posture is different from the previous (first) head image. Then, the orientation measurement means 103 measures the horizontal shooting direction of the image acquisition means 101, and the included angle (hereinafter, as shown in FIG. 8) formed by the current (second) horizontal shooting direction and the previous (first) horizontal shooting direction. ) is evaluated (Step 30 in FIG. 3). That is, when the directional difference is less than the predetermined "angle threshold" (Yes in Step 30 of FIG. 3), the process proceeds to the next process, and when the directional difference exceeds the angle threshold (No in Step 30 of FIG. 3), the warning means 104 will alert you to a warning.

In order for the model creating means 102 to connect a plurality of head images to create a 3D model of the head, the head images need to overlap (wrap) to some extent. That is, if the directional difference due to two consecutive shots becomes excessively large, the head images do not overlap appropriately, and as a result, an appropriate 3D model of the head cannot be created. Therefore, an angle threshold value is set in advance, and when the horizontal shooting direction for subsequent shooting is inappropriate (that is, the direction difference exceeds the angle threshold value), the warning means 104 notifies a warning, so that appropriate horizontal shooting is performed. It urges you to correct the direction. Note that the magnitude of the angle threshold can be appropriately set according to the situation. For example, in FIG. 8, the angle threshold is set to 15°, and the directional difference is also maintained at the angle threshold (that is, 15°), and the images are captured from 24 directions. Of course, it is not limited to this, and it is possible to shoot with various angle thresholds and directional differences depending on the situation, such as shooting from 16 directions with an angle threshold of 22.5°.

In order to photograph with an appropriate directional difference, posture guide means shown in FIG. 9 can be used. As shown in this figure, the posture guidance means is a means for transmissively displaying the stereoscopic face model FM on the display section (such as a liquid crystal display) of the image acquisition means 101 such as a smartphone. Further, the posture guide means rotates the stereoscopic face model FM about the vertical axis by a predetermined angle (hereinafter referred to as "unit rotation angle") each time the image acquisition means 101 takes an image, and causes the stereoscopic face model FM to be transparently displayed.

In this case, the photographer should match the orientation of the subject's head (particularly the face) with the orientation of the stereoscopic face model FM before photographing. If the unit rotation angle is set to be equal to or less than the angle threshold, it is possible to photograph with an appropriate directional difference. Furthermore, the posture guidance means has a function of notifying that effect (completion of all-around imaging) when imaging from a plurality of directions covering the entire circumference of the head (that is, from 360° directions as shown in FIG. 8) has been completed. You can prepare. For example, when a predetermined number of times of photographing (for example, a value obtained by dividing 360° by a unit rotation angle) is counted, or based on the result measured by the attitude measurement means 103, "perimeter photographing completion" is notified. can be done.

Head images are sequentially acquired so as to cover the entire circumference of the head while moving around the subject, that is, while changing the horizontal imaging direction while maintaining an appropriate directional difference. Acquisition of the head image ends when the entire circumference of the head has been covered by the photographer's own judgment or by the notification of "completion of imaging of the entire circumference" by the posture guidance means (Yes in Step 50 of FIG. 3). The acquired head image is stored in the head image storage means 106 .

When a head image that covers the entire circumference of the subject's head can be obtained, a 3D model of the subject's head is created by the model creating means 102 (Step 60 in FIG. 3). Specifically, the model creation means 102 reads out a plurality of head images from the head image storage means 106, bundle adjustment using stereo pair images, and a head 3D model using a photogrammetry technique such as SfM (Structure from Motion). Create a model. At this time, since the images were taken while maintaining an appropriate directional difference, the adjacent head images partially overlapped (wrapped) appropriately, and the "character (or group of characters)" displayed in the overlapped part is a feature. It is suitably used as a point. Of course, the "character (or character group)" used as the feature point is displayed on the printing sheet 200 such as the hat type printing sheet 200C and the apron type printing sheet 200A.

When the 3D model of the subject's head is created, the 3D model of the head is output by an output means 107 such as a display or a printer. In particular, if a 3D model of the head is output by a 3D printer, it can be effectively used when creating a wig base.

3. 3D Head Model Creation Method Next, the 3D head model creation method of the present invention will be described with reference to the drawings. The 3D head model creation method of the present invention is a method of creating a 3D head model using the 3D head model creation system 100 described above. 2. Only the contents specific to the three-dimensional head model creation method of the present invention will be described, avoiding descriptions that overlap with the contents described in . That is, the contents not described here are the same as those described in "2. Three-dimensional head model creation system".

FIG. 10 is a flowchart showing main steps of the three-dimensional head model creation method of the present invention. As shown in this figure, first, the subject wears the print sheet 200 and performs a "preparation step" in which the scale 300 is arranged at an appropriate position (Step 201). As described above, the subject can wear the printing sheet 200 by wearing the hat-type printing sheet 200C, and may additionally wear the apron-type printing sheet 200A.

When the preparation is complete, the photographer acquires head images (Step 202). More specifically, while moving around the subject (while changing the horizontal imaging direction while maintaining an appropriate directional difference), head images are sequentially acquired until the entire circumference of the head is covered. Then, the model creation means 102 reads a plurality of head images from the head image storage means 106 and creates a 3D model of the subject's head using these head images (Step 203).

The three-dimensional head model creation system and three-dimensional head model creation method of the present invention can be used for wigs that cover the entire head, partial wigs that partially cover the head, wigs, etc., and also for grasping the size of hats and helmets. It can also be used in other cases.

100 3D head model creation system 101 Image acquisition means (of 3D head model creation system) 102 Model creation means (3D head model creation system) 103 Posture measurement means (3D head model creation system) 104 Warning means (of the 3D head model creation system) 105 Posture guide means (of the 3D head model creation system) 106 Head image storage means (of the 3D head model creation system) 107 (3D head model Output means of production system 200 print sheet 200A apron type print sheet 200C hat type print sheet 300 scale FM stereoscopic face model

Claims (7)

A system for creating a three-dimensional model of a head based on images of the head, comprising:
an image acquiring means for acquiring a head image, which is an image of a state in which the print sheet is in close contact with the head;
a model creation means for creating the three -dimensional model of the head by performing spatial arithmetic processing on the head image captured from a plurality of directions so as to cover the entire circumference of the head;
The printed sheet is displayed so that a plurality of characters are spread like newspapers and magazines,
Some of the plurality of head images used by the model creating means contain a scale with existing dimensions,
The model creation means connects the adjacent head images using a "character group" consisting of two or more characters displayed in the overlapped portion of the head images as a feature point, thereby forming the three-dimensional model. to create
A three-dimensional head model creation system characterized by: attitude measurement means for measuring the attitude of the image acquisition means;
further comprising warning means for notifying a warning when a difference between the horizontal shooting direction of the image acquisition means and the horizontal shooting direction at the time of previous shooting exceeds an angle threshold,
The horizontal shooting direction is a direction obtained by projecting the shooting direction of the image acquisition means onto a horizontal plane.
3. The three-dimensional head model creation system according to claim 1, characterized by: further comprising posture guidance means for guiding the photographing posture of the image acquisition means by transparently displaying the stereoscopic face model on the display section of the image acquisition means;
When the head image is acquired by the image acquiring means, the posture guiding means rotates the stereoscopic face model about a vertical axis by a predetermined angle and causes the stereoscopic face model to be transparently displayed.
3. The three-dimensional head model creation system according to claim 1 or 2, characterized in that: A method for creating a three-dimensional model of a subject's head based on a plurality of images of the subject's head, comprising:
a preparation step in which the subject attaches the print sheet to the head so as to cover the entire head and to be in close contact with the head;
an image acquisition step of acquiring a plurality of head images by photographing the head on which the print sheet is attached while moving around the subject;
a model creation step of creating the three -dimensional model of the subject's head by performing spatial arithmetic processing on the plurality of head images acquired in the image acquisition step;
The printed sheet is displayed so that a plurality of characters are spread like newspapers and magazines,
In the model creation step, the adjacent head images are connected using a "character group" consisting of two or more characters displayed in the overlapped portion of the head images as a feature point, thereby forming the three-dimensional model. to create
A three-dimensional head model creation method characterized by: In the preparation step, the subject wears the printed sheet on which the newspaper surface is printed on the head.
5. The three-dimensional head model creation method according to claim 4, wherein: In the preparation step, the subject wears a cap formed of the printed sheet.
6. The method of creating a three-dimensional head model according to claim 4 or 5, characterized in that: In the preparation step, the subject wears an apron or a cape formed of the printed sheet in addition to wearing the printed sheet on the head,
In the image acquisition step, an image of the head is acquired while wearing the apron or the cape.
The three-dimensional head model creation method according to any one of claims 4 to 6, characterized in that:

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