JP6847354B1 - Three-dimensional data unevenness binarization display method and three-dimensional data unevenness binarization display program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To grasp the shape of an entire object to be measured three-dimensionally and to obtain binarized irregularities on the surface of the object. SOLUTION: Image data obtained by photographing a measurement object 20 from various angles, or position data acquired by scanning a measurement object 20 from various angles including a plurality of reference objects 22 by a laser scanner is obtained by a computer 30. The point group data of the measurement target 20 is acquired from a plurality of image data or a plurality of position data, and based on the point group data, polygon data including the surface of the measurement target is created and the created polygon data. The color of the copied polygon data is changed to a color different from that of the copy source polygon data, the surface of the copied polygon data is smoothed, and the copied polygon data after the smoothing process and the copy source Overlay with polygon data. [Selection diagram] Fig. 4

Description

The present invention is a method and a program capable of displaying the unevenness of an object in an easy-to-see and accurate manner according to a visual purpose after generating three-dimensional data from a plurality of photographs or position data obtained by laser scanning on the object to be measured. Regarding.

Traditionally, a technique called rubbing has been used to copy patterns and characters drawn on the surface of earthenware and stone monuments. Takumoto sticks the paper on the surface of earthenware and stone monuments while spraying water, and when the paper is half-dried, he puts ink on the tampo and injects the ink on the surface of the paper. This makes it possible to copy the patterns and characters on the surface of the object onto paper.

However, if ink is applied to historically valuable cultural properties or fragile objects such as earthenware, the objects may be soiled, and the rubbing could only be carried out in a limited number of cases. .. Furthermore, in the case of important cultural properties, there are some that require permission to touch.
In addition, it takes a lot of time and effort to put Japanese paper on a plurality of pieces of relics, a large stone monument, etc., and to copy the unevenness of the relics with tampo, ink, etc. Also, depending on the thing, the work requires skill, and the workmanship may differ.
Therefore, electronic rubbing books as shown in Patent Documents 1 and 2 have been proposed.

In the electronic rubbing method shown in Patent Document 1 (Japanese Unexamined Patent Publication No. 7-270142), unevenness is detected by irradiating the stamped characters with a laser beam, and this detection signal is calculated to calculate the stamped characters. It recognizes the shape.
Further, in the image pickup device for electronic takumi shown in Patent Document 2 (Japanese Unexamined Patent Publication No. 2007-104088), the device is arranged in close proximity to or in close contact with the subject, and a light emitting element that emits illumination light and the subject. It is provided with a light receiving element for receiving the reflected light from the light emitting element, an imaging sheet in which the light emitting element and the light receiving element are alternately arranged, and a control unit for signal processing the captured image data read from the imaging sheet. ing.

Japanese Unexamined Patent Publication No. 7-270142 JP-A-2007-104888

In the electronic rubbing method as in Patent Document 1, the engraved characters are read by irradiating them with a laser beam, and only flat subjects can be handled.
Further, since the device as in Patent Document 2 can be bent, it is possible to take a picture so as to cover the periphery of the subject. However, the apparatus of Patent Document 2 merely obtains patterns, characters, and the like on the surface of the subject as data, and cannot grasp the structure of the entire subject in three dimensions.

Therefore, the present invention has been made to solve the above problems, and the purpose of the present invention is to be able to grasp the shape of the entire object to be measured three-dimensionally and to obtain the unevenness of the surface of the object by binarizing it. To provide methods and programs.

According to the three-dimensional data unevenness binarization display method according to the present invention, the unevenness of the surface of the object to be measured in the three-dimensional data composed of polygon data is binarized and displayed, and the measurement is performed by a digital camera. Image data obtained by photographing the object from various angles or position data obtained by scanning the object to be measured from various angles with a laser scanner is input to the computer, and the computer receives the plurality of image data or the said. Point group data of the measurement object was acquired from a plurality of position data, polygon data including the surface of the measurement object was created based on the point group data, and the created polygon data was copied and copied. Change the color of the polygon data to a color different from that of the copy source polygon data, smooth the surface of the copied polygon data, and superimpose the copied polygon data after the smoothing process with the copy source polygon data. As a result, the data is processed so that the convex portion and the concave portion on the surface of the surface of the copy source polygon data are hidden and displayed in different colors.
By adopting this method, after the point cloud data is acquired, the characters and patterns on the surface of the measurement target can be displayed so that the concave portion and the convex portion have different colors based on the polygon data. This is a technique that is possible because the unevenness of the object surface can be grasped by using polygon data in which the object surface is formed as data, and it is not possible to observe only from the front of the unevenness as in the conventional case. According to the present invention, it is possible to display such a concave portion and a convex portion in different colors extremely easily, and it is also possible to display the entire structure of the object to be measured as three-dimensional data. Is.

Further, the color different from the polygon data of the copy source is the background color, and by superimposing the polygon data copied after the smoothing process and the polygon data of the copy source, the unevenness of the surface of the polygon data of the copy source is formed. It may be characterized in that data processing is performed so that only the convex portion of is displayed.
According to such a method, the concave portion in the unevenness of the object to be measured becomes the background color, and only the convex portion is colored, so that the display can be performed in the same manner as when the rubbing is taken.

Further, the computer may be characterized in that the smoothness of the smoothing process can be adjusted.
According to such a method, for example, even if the unevenness of the surface of the object to be measured is shallow and the unevenness cannot be recognized by the supplementary method or the device such as Patent Document 1 or Patent Document 2, the smoothness By adjusting so as to increase, it is possible to reliably recognize the unevenness and display the accurately binarized unevenness.

Further, the computer is provided so that the overlay position of the copied polygon data after the smoothing process can be partially or entirely moved in the height direction of the unevenness on the copy source polygon data by the operation of the operator. It may be characterized by being present.
According to such a method, for example, when the surface of the object to be measured has shallow irregularities, even if the copied polygon data and the copy source polygon data are superimposed, the convex portion of the copied polygon data and the copy source polygon data There is a possibility that the height of the polygon data will be very close to each other and the convex part of the polygon data of the copy source will not be clearly visible. Therefore, by setting the surface of the copied polygon data after the smoothing process to a position lower than the surface of the copy source polygon data, the area of the convex portion of the copy source polygon data is expanded and the convex portion is clearly displayed. Can be made to. Further, even when the unevenness of the surface of the measurement object is partially shallow, the surface of the copied polygon data after the smoothing process is set at a position lower than the surface of the copy source polygon data only in that portion. , The area of the convex portion of the polygon data of the copy source, which was partially shallow, can be expanded to clearly display the convex portion.
Further, for example, when a deep concave portion is present on the surface of the object to be measured and fine irregularities are also present on the surface of the deep concave portion, it may be considered unnecessary to display the convex portion in the deep concave portion. In such a case, the unevenness of the deep concave surface can be hidden by setting the surface of the copied polygon data after the smoothing process of the portion corresponding to the deep concave portion to a position higher than the surface of the copy source polygon data. It is possible to hide the convex part in the deep concave part.

Further, the computer generates a plurality of copied polygon data by further copying the copied polygon data or copying a plurality of polygon data from the original polygon data, and the plurality of generated copy polygon data. The smoothness of the smoothing process may be partially different, and a plurality of copied polygon data after the smoothing process may be overlaid with the copy source polygon data.
According to such a method, for example, when a deep concave portion exists on the surface of the object to be measured and fine unevenness also exists on the surface of the deep concave portion, it is considered unnecessary to display the convex portion in the deep concave portion. There is also a case. In such a case, the convex part of the copy source polygon data on the surface other than the deep hole is displayed by the copied polygon data after the first smoothing process, and the inside of the deep hole is displayed for the other copied polygon data. By performing a smoothing process that hides the unevenness of the polygon, it is possible to hide the convex portion in the deep concave portion.

According to the three-dimensional data unevenness binarization display method and program of the present invention, the unevenness can be binarized and displayed extremely easily using the point cloud data.

It is explanatory drawing at the time of photographing the measurement object. It is a block diagram which shows the structure of a computer. It is a flowchart of a point cloud data generation program. It is a flowchart of a three-dimensional data unevenness binarization program. It is explanatory drawing which shows the procedure 1 of the three-dimensional data unevenness binarization program. It is explanatory drawing which shows the procedure 2 of the three-dimensional data unevenness binarization program. It is explanatory drawing which shows the procedure 3 of the three-dimensional data unevenness binarization program. It is explanatory drawing which shows the procedure 4 of the three-dimensional data unevenness binarization program. This is an example of binarizing archaeological sites using a three-dimensional data unevenness binarization program. This is an example of binarizing earthenware using a three-dimensional data unevenness binarization program. This is an example of binarizing a fossil using a three-dimensional data unevenness binarization program. It is explanatory drawing which shows the state which the convex part in a deep concave part is also displayed. It is explanatory drawing which shows the place where a part of the model 2 is moved in the height direction. It is explanatory drawing which shows the place where a part of the model 2 was moved in the height direction and superposed on the model 1. It is explanatory drawing which shows the place where the model 3 was generated by performing the smoothing process on the polygon data which copied the model 2. It is explanatory drawing which shows the place where the model 2 and the model 3 are superposed on the model 1.

(First Embodiment)
Hereinafter, an embodiment in which a measurement object is photographed by a digital camera and point cloud data is acquired based on the image data will be described.
First, a method of photographing an object to be measured will be described. FIG. 1 shows a state in which a plurality of images of a measurement object are photographed around the object by a digital camera.
The object to be measured 20 may be any object, but FIG. 1 shows a simple columnar object as an example. In reality, the objects to be measured include objects such as archaeological sites, earthenware, fossils, and stone monuments for which surface irregularities are to be measured in detail.

The operator takes a plurality of pictures of the object 20 to be measured with a digital camera so as to cover the entire circumference from various angles. In addition, it is necessary to perform shooting by overlapping the shooting ranges. Data matching processing is performed on the overlapped portion as described later.
Further, the number of shots is better as the number of shots is larger in order to acquire accurate point cloud data, but the operator appropriately determines the number of shots in consideration of the processing time in the computer.
After the shooting is completed, the operator causes the computer to capture the shot image data.

Next, the operation in the computer will be described with reference to FIG. FIG. 2 is a block diagram showing an outline of the internal configuration of the computer.
As the computer, a general personal computer can be adopted. The computer 30 has a control unit 32 and a storage device 34 inside. The control unit 32 includes a central processing unit (CPU, etc.), a memory (ROM, RAM), etc., controls the overall operation of the computer 30, and executes and controls functions based on each program stored in the storage device 34. To do.
Further, the computer 30 may be equipped with a graphic board including a GPU.

The storage device 34 is composed of a hard disk drive, an SSD, or the like. In addition to storing captured image data, the storage device 34 stores in advance a point cloud data generation program P1 and a three-dimensional data unevenness binarization program P2.
As the point cloud data generation program P1, a known program can be used. The point cloud data generation program P1 executes the operation as shown in FIG. However, the point cloud data generation program P1 shown here may be one program integrated with the three-dimensional data unevenness binarization program described later.

The computer 30 further includes an input device 36 composed of a mouse, a keyboard, and the like, point cloud data generated by the point cloud data generation program P1, polygon data generated by the three-dimensional data unevenness binarization program P2, and polygons. A monitor 38 is provided which displays data obtained by copying data, changing the color, performing smoothing processing, superimposing the copy source polygon data, and binarizing the surface irregularities of the original polygon data.

Next, the outline of the operation of the point cloud data generation program will be described with reference to FIG.
When the point cloud data generation program is started to be executed, it extracts a plurality of feature points from the plurality of captured image data (S101). As feature points, many parts that are different in color and shape from other parts are extracted.

Next, the point cloud data generation program executes a matching process for matching the features of a plurality of image data (S102). A plurality of image data are generated as point cloud data by the matching process.
The point cloud data generation program may generate point cloud data so that the point cloud data is at a relatively correct position by matrix calculation by inputting camera parameters and the like until the matching process.
Incidentally, as an existing point cloud data generation program, software called Structure from Motion (SfM) or Multi-View Stereo (MVS) that generates point cloud data from image data is known.

After the point cloud data is generated, when the operator creates the unevenness binarization data of the surface of the measurement object 20, the input device 36 is operated to execute the three-dimensional data unevenness binarization program P2.
The operation of the three-dimensional data unevenness binarization program P2 will be described with reference to FIGS. 4 and 5 to 8. FIG. 4 shows an operation flowchart of the three-dimensional data unevenness binarization program P2, and FIGS. 5 to 8 show an example of polygon data when the unevenness binarization program is executed.

The three-dimensional data unevenness binarization program P2 creates polygon data including the surface of the measurement object 20 based on the created point cloud data (step S201). The polygon data is obtained by connecting points at the same height position from the point cloud data and filling the surface thereof to generate a three-dimensional surface.
In addition, in FIGS. 5 to 8, the polygon data is viewed from the cross-sectional direction in order to grasp the present invention, but in reality, the operator can see the binarized uneven surface on the monitor 38. Configured to do the work.

In FIG. 5, the polygon data of the target for detecting the unevenness of the surface is referred to as model 1.
Next, the three-dimensional data unevenness binarization program P2 copies the polygon data of the created model 1 and changes the color of the copied polygon data to a color different from that of the copy source polygon data (step S202). The copied polygon data is referred to as model 2.
The color of the model 2 may be different from that of the model 1, but it is preferably a background color. In the example of FIG. 5, the color of the model 2 is white, which is the background color (in FIG. 5, if it is white, it cannot be seen as a drawing, so it is gray).

Next, the three-dimensional data unevenness binarization program P2 smoothes the surface of the copied polygon data (step S203). The smoothing process may also be referred to as a smoothing filter process, and is executed as a filter process for smoothing the surface irregularities of the model 2. Specifically, a moving average filter and the like are known.
Next, the three-dimensional data unevenness binarization program P2 superimposes the copied polygon data (model 2) after the smoothing process and the copy source polygon data (model 1) (step S204). By doing so, the convex portion of the surface unevenness in the model 1 remains the color of the model 1, and the concave portion of the model 1 appears as the smoothed concave portion of the model 2 and the concave portion of the model 1 is hidden. Therefore, the unevenness can be displayed on the monitor 38 as binarized data of the color of the model 1 and the color of the model 2.
Further, as described above, the binarized surface irregularities of the polygon data were turned from the front instead of from the cross-sectional direction as shown in FIGS. 5 to 8 when displayed on the monitor 38. Display the data.

By using the color of the model 2 as the background color, when the model 2 and the model 1 are overlapped with each other, only the convex portion of the model 1 is located in the concave portion of the model 1 because the model 2 of the background color is located. Is displayed. In particular, by changing the color of the model 1 to black, it becomes easier to clarify the unevenness of the measurement object 20.
This state is the same as when the rubbing is taken (the surface is blackened by black ink, and the recesses are white without black ink). Therefore, when it is difficult to rub a high-value item or a fragile item, it can be rubbed reliably and easily.

In addition, when the surface unevenness of the model 1 is shallow, if the smoothness of the smoothing process of the model 2 is low, the difference between the model 1 and the model 2 may be small and it may not be possible to clearly binarize.
Therefore, the smoothness of the smoothing process in the three-dimensional data unevenness binarization program P2 may be changed by the setting of the operator. The smoothness can be changed, for example, by changing the multiplication value of the moving average filter.
Further, the three-dimensional data unevenness binarization program P2 displays the binarized convex portion and the concave portion of the polygon data on the monitor 38 so that the binarized convex portion and the concave portion of the polygon data can be seen from the front while the smoothing process is being executed, and the operator can see the convex portion. It is preferable to be able to adjust the smoothness of the smoothing process while considering the size of the area or the visibility.

9 to 11 show a specific example when the three-dimensional data unevenness binarization program of the present embodiment is executed.
In FIG. 9, the left side is a normal image of the ruins taken from a plane, and the right side is a display of the data obtained by binarizing the unevenness. In this way, according to the data obtained by binarizing the unevenness, the pattern of the earthenware, which is difficult to see in a normal image, can be clearly confirmed.

FIG. 10 shows a normal image of the pottery taken from the side on the left side, and displays the data obtained by binarizing the unevenness on the right side. In this way, according to the data obtained by binarizing the unevenness, the pattern of the earthenware, which is difficult to see in a normal image, can be clearly confirmed.

FIG. 11 shows animal fossils, the top image is a normal image of the fossil taken from the side, and the second from the top is the uneven binarized data. The second image from the bottom is a normal image of a fossil taken from a flat surface, and the bottom image is a display of data obtained by binarizing unevenness.
As described above, the object to be measured is not limited to artificial objects such as archaeological sites, earthenware, and stone monuments, and even fossils and the like can be clearly confirmed as cracks that are difficult to see in a normal image.

(Second embodiment)
Next, an embodiment in which the overlay position of the copied polygon data after the smoothing process can be partially or entirely moved in the height direction of the unevenness on the copy source polygon data by an operator's operation. Will be described.
The three-dimensional data unevenness binarization program P2 moves the superimposition position of the copied polygon data after the smoothing process on the copy source polygon data in the height direction of the unevenness partially or entirely by the operation of the operator. It has a function to make it.

Specific examples of this embodiment are shown in FIGS. 12 to 14. Although FIGS. 12 to 14 show polygon data viewed from the cross-sectional direction, the operator is configured to actually perform the work while observing the binarized uneven surface on the monitor 38.
In FIG. 12, the polygon data to be detected for surface irregularities is set as model 1 (black), the polygon data of model 1 is copied by the three-dimensional data unevenness binarization program P2, and the color of the copied polygon data is copied. The polygon data changed to a color different from the original polygon data is set as model 2 (white), and the model 1 and the model 2 are superimposed.

In the state of FIG. 12, even the unevenness of the surface in the deep recess is displayed, but when the operator thinks that the unevenness of the surface in the deep recess does not need to be displayed, the operator is an input device 36 such as a mouse. Use to select the location in model 2 that you want to move in the height direction.
FIG. 13 shows that the operator selects a portion corresponding to the deep concave portion of the model 2 and pulls up the portion corresponding to the deep concave portion of the model 2 in order to erase the convex portion in the deep concave portion.

FIG. 14 shows that the convex portion in the deep concave portion is hidden by the model 2 and the convex portion in the deep concave portion is not displayed by pulling up the portion corresponding to the deep concave portion in the model 2.

In the examples of FIGS. 12 to 14, the case where the model 2 is moved upward has been described, but the model 2 can also be moved downward.
For example, when the unevenness of the object to be measured is shallow, the area of the convex portion may become very small as a result of superimposing the model 1 and the model 2. In such a case, the operator can move the model 2 downward as a whole or partially to expand the area of the convex portion and display the state of the convex portion in an easy-to-understand manner.

(Third Embodiment)
Next, an embodiment in which the three models can be superposed by the operation of the operator will be described.
The three-dimensional data unevenness binarization program P2 in this embodiment further copies the copied polygon data after the smoothing process by the operation of the operator, and changes the smoothness of the smoothing process of the recopied polygon data. The copied polygon data, the recopied polygon data, and the original polygon data are superimposed.

Specific examples of this embodiment are shown in FIGS. 15 to 16. Although FIGS. 15 to 16 show the polygon data viewed from the cross-sectional direction, the operator is configured to actually perform the work while observing the binarized uneven surface on the monitor 38.
The example shown here is the same as the state shown in FIG. 12, and shows a place where the original polygon data and the polygon data that has been copied and smoothed are superimposed, and even the unevenness of the surface in the deep recess is reached. It is displayed.

When the operator thinks that the unevenness of the surface in the deep recess does not need to be displayed, as shown in FIG. 15, the operator uses an input device 36 such as a mouse to execute the three-dimensional data unevenness binarization program P2. The model 2 is further copied by the operation, and the copied polygon data is subjected to a smoothing process having a smoothness higher than that of the model 2 to create the model 3. The color of the model 3 is the same as the color of the model 2.
The model 3 has polygon data having a higher smoothness than the model 2. In particular, the depth of the portion corresponding to the deep recess is considerably shallow.

Next, as shown in FIG. 16, the three-dimensional data unevenness binarization program P2 superimposes the model 1, the model 2, and the model 3.
Then, since the concave portion of the model 1 is hidden by the model 2 and the model 3, and the convex portion in the deep concave portion of the model 1 is also hidden by the model 3, the convex portion in the deep concave portion can be hidden.

In the above-described embodiment, an example in which point cloud data is generated based on a plurality of image data taken by a digital camera has been described.
However, the generation of the point cloud data in the present invention may be based on the position data obtained by the laser scanner.

20 Object to be measured 30 Computer 32 Control unit 34 Storage device 36 Input device 38 Monitor P1 Point cloud data generation program P2 Three-dimensional data unevenness binarization program

Claims (10)

It is a method of binarizing and displaying the unevenness of the surface of the object to be measured in the three-dimensional data composed of polygon data.
Image data obtained by photographing the measurement object from various angles with a digital camera or position data obtained by scanning the measurement object from various angles with a laser scanner is input to a computer.
The computer
The point cloud data of the measurement object is acquired from the plurality of image data or the plurality of position data, and the point cloud data is acquired.
Based on the point cloud data, polygon data including the surface of the measurement object is created.
Copy the created polygon data and
Change the color of the copied polygon data to a color different from the color of the copy source polygon data,
Smooth the surface of the copied polygon data
By superimposing the copied polygon data after the smoothing process and the copy source polygon data, the uneven convex portion and the concave portion on the surface of the copy source polygon data are hidden and different colors are used. A three-dimensional data unevenness binarization display method characterized in that data is processed so as to be displayed. The color different from the polygon data of the copy source is the background color.
According to the polygon data copied after smoothing processing, by superimposing the copy source polygon data, characterized in that the data processing so that only the convex portion of the unevenness of the surface of the copy source polygon data is displayed Item 1. The three-dimensional data unevenness binarization display method according to Item 1. The computer
The three-dimensional data unevenness binarization display method according to claim 1 or 2, wherein the smoothness of the smoothing process is adjustable. The computer
It is characterized in that the overlay position of the copied polygon data after the smoothing process is provided so as to be movable in the height direction of the unevenness partially or entirely by the operation of the operator. The three-dimensional data unevenness binarization display method according to any one of claims 1 to 3. The computer
Multiple copied polygon data is generated by further copying the copied polygon data or by copying a plurality of polygon data from the original polygon data.
The smoothness of the smoothing process of the polygon data of multiple generated copies is partially different,
The three-dimensional data unevenness binarization display according to any one of claims 1 to 4, wherein a plurality of copied polygon data after the smoothing process and the copy source polygon data are superimposed. Method. It is a program that binarizes and displays the unevenness of the surface of the object to be measured in the three-dimensional data composed of polygon data in the computer.
Image data obtained by photographing the measurement object from various angles, or point group data after acquiring the point group data of the measurement object from the position data acquired by scanning the measurement object from various angles with a laser scanner. In the function of creating polygon data including the surface of the object to be measured,
The function to copy the created polygon data and
A function to change the color of the copied polygon data to a color different from the color of the copy source polygon data,
A function to smooth the surface of the copied polygon data,
By superimposing the copied polygon data after the smoothing process and the copy source polygon data, the uneven convex portion and the concave portion on the surface of the copy source polygon data are hidden and different colors are used. A three-dimensional data unevenness binarization display program characterized by having a computer execute a function of processing data so that it is displayed. The color different from the polygon data of the copy source is the background color.
By superimposing the copied polygon data after the smoothing process and the copy source polygon data, the computer is made to execute a data processing function so that only the convex portion of the surface of the copy source polygon data is displayed. The three-dimensional data unevenness binarization display program according to claim 6 , wherein the three-dimensional data unevenness is binarized. The three-dimensional data unevenness binarization display program according to claim 6 or 7 , wherein a computer executes a function capable of adjusting the smoothness of the smoothing process. The feature is that the computer is made to execute a function of partially or wholly moving the overlay position of the copied polygon data after the smoothing process to the copy source polygon data in the height direction of the unevenness by the operation of the operator. The three-dimensional data unevenness binarization display program according to any one of claims 6 to 8. A function to generate multiple copied polygon data by further copying the copied polygon data or copying multiple polygon data from the original polygon data.
The function to partially different the smoothness of the smoothing process of polygon data of multiple generated copies, and
The tertiary according to any one of claims 6 to 9, wherein a computer executes a function of superimposing a plurality of copied polygon data after smoothing processing and a copy source polygon data. Original data unevenness binarization display program.

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