Method and program for estimating volume of object, computer-readable storage medium stored with the program, and computer having the program installed

Abstract

To provide a method for efficiently estimating the volume of an object based upon an image of the object.SOLUTION: A method includes: (1) acquiring a first image, a second image and a third image of an object from a first point in a first upward direction from the object, a second point in a right direction relative to the first direction and a third point in a left direction relative to the first direction, respectively; (2) setting a first occupied region, a second occupied region and a third occupied region in the first to the third images which are 80 to 120% of the area of the object; (3) setting a fourth occupied region in the first image which includes a part of the object located on a first point side and is narrower than the first occupied region; and (4) finding the volume V of the object from the equation shown below.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] One embodiment of the present invention relates to a method for estimating the volume of an object, for example, a method and a program for estimating the volume of an object using an image of the object, a computer-readable storage medium on which the program is stored, and a computer on which the program is installed. [Background technology]

[0002] There are known methods for estimating the volume of an object using an image of the object. For example, Patent Document 1 discloses a method for estimating the volume of a boulder or the like that is partially buried underground. In this method, images of the object are acquired from different angles, and these images are used to construct a virtual polyhedron and calculate its volume, thereby making it possible to estimate the volume of the object without actually measuring its size. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2024-019944 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-described volume estimation method, the volume is estimated by defining the area occupied by an object in each image using four points, which may result in an inaccurate grasp of the three-dimensional shape of the object. In particular, it is difficult to accurately capture the unevenness of the surface in a frontal image of the object, so the volume may not be accurately estimated for objects with many uneven surfaces. One embodiment of the present invention aims to provide a novel method for estimating the volume of an object. Alternatively, one embodiment of the present invention aims to provide a method for accurately and efficiently estimating the volume of an object based on an image of the object. [Means for solving the problem]

[0005] One embodiment of the present invention is a method for estimating the volume of an object, which includes: (1) acquiring a first image, a second image, and a third image of the object from a first point on a first direction from the object, a second point to the right of the first direction, and a third point to the left of the first direction, respectively; (2) setting a first occupation area, a second occupation area, and a third occupation area in the first, second, and third images, respectively, each occupying 80% to 120% of the area of ​​the object; (3) setting a fourth occupation area in the first image, the fourth occupation area including a portion of the object located on the side of the first point and being smaller than the first occupation area; and (4) calculating a volume V of the object according to the following formula:

[0006]

number

[0007] A1 and A2 are the areas of the first and fourth occupied regions, respectively. D L and D R are expressed by the following formulas, respectively.

[0008]

number

[0009] A L and A R are the areas of the second and third occupancies, respectively. L L and L R are the lengths of the second and third occupancy areas in the second direction intersecting the horizontal direction, respectively.

[0010] One embodiment of the present invention is a program for estimating the volume of an object. The program is configured to cause a processing device to (1) accept an instruction to set a first occupation area, a second occupation area, and a third occupation area occupying 80% to 120% of the area of ​​the object in a first image, a second image, and a third image of the object acquired from a first point on a first direction from the object, a second point to the right of the first direction, and a third point to the left of the first direction, respectively; (2) accept an instruction to set a fourth occupation area in the first image, the fourth occupation area including a portion of the object located on the first point side and being smaller than the first occupation area; (3) calculate the area of ​​the fourth occupation area from the first occupation area; (4) calculate the lengths of the second occupation area and the third occupation area in a second direction intersecting the horizontal direction; and (5) calculate the volume V of the object according to the following equation:

[0011]

number

[0012] A1 and A2 are the areas of the first and fourth occupied regions, respectively. D L and D R are expressed by the following formulas, respectively.

[0013]

number

[0014] A L and A R are the areas of the second and third occupancies, respectively. L L and L R are the lengths of the second and third occupancies, respectively.

[0015] One embodiment of the present invention is a computer-readable storage medium on which the above program is recorded.

[0016] One embodiment of the present invention is a computer on which the above program is installed. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a flowchart illustrating a method for estimating the volume of an object, according to one embodiment of the present invention. [Figure 2A] 1 is a schematic perspective view illustrating a method for estimating the volume of an object according to one embodiment of the present invention; [Figure 2B] 1A-1C are schematic top views illustrating a method for estimating the volume of an object according to one embodiment of the present invention. [Figure 3] 1 is a schematic diagram illustrating a method for estimating the volume of an object according to one embodiment of the present invention. [Figure 4] 1 is a schematic diagram illustrating a method for estimating the volume of an object according to one embodiment of the present invention. [Figure 5] 1 is a schematic diagram illustrating a method for estimating the volume of an object according to one embodiment of the present invention. [Figure 6A] 1A and 1B are schematic front views illustrating a method for estimating the volume of an object according to one embodiment of the present invention. [Figure 6B] 1A-1C are schematic side views illustrating a method for estimating the volume of an object according to one embodiment of the present invention. [Figure 7] 1 is a schematic diagram illustrating a method for estimating the volume of an object according to one embodiment of the present invention. [Figure 8] 1 is a schematic diagram illustrating a method for estimating the volume of an object according to one embodiment of the present invention. [Figure 9] 1 is a flowchart illustrating a method for estimating the volume of an object, according to one embodiment of the present invention. [Figure 10] 1 is a schematic diagram illustrating a method for estimating the volume of an object according to one embodiment of the present invention. [Figure 11] 1 is a schematic diagram illustrating a method for estimating the volume of an object according to one embodiment of the present invention. [Figure 12]FIG. 1 is a block diagram of a computer according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, various embodiments of the present invention will be described with reference to the drawings, etc. However, the present invention can be embodied in various forms without departing from the spirit of the present invention, and should not be construed as being limited to the description of the embodiments exemplified below.

[0019] 1. How to estimate the volume of an object One embodiment of the present invention is a method for estimating the volume of an object. This method is not limited to specific objects and can be applied to various objects with three-dimensional shapes. One example of an object is boulders, i.e., stones and rocks scattered along mountain slopes or riverbanks. Depending on the location, boulders are often difficult for workers to approach and measure, and surveying them can be dangerous. However, as described in detail below, this method can efficiently estimate the volume by using images of the object acquired from three different directions. This method can also efficiently estimate the volume by acquiring images of the entire boulder, or even if the boulder is partially buried underground and not fully exposed, by using images of the object acquired from three different directions. Furthermore, the images of the object do not necessarily need to be acquired by workers carrying an imaging device; an unmanned vehicle or unmanned aerial vehicle equipped with an imaging device can also be used. Therefore, the volume of a boulder can be quickly estimated while ensuring the safety of workers. Below, this method will be described in detail using a boulder as an example of an object.

[0020] A flowchart of this method is shown in Figure 1. In this method, an image of the boulder is first acquired, and the area occupied by the boulder in the acquired image is set. This area is used to construct a virtual three-dimensional object that approximates the boulder, and its volume is calculated to estimate the volume of the boulder.

[0021] (1) Image acquisition As shown in FIG. 2A, images of the boulder are acquired from three different points. The three points may be at the same or different vertical heights (altitudes). Similarly, the three points may be at the same or different distances from the boulder. Furthermore, when the boulder is viewed from above, as shown in FIG. 2B, if a first point is located in a first direction from the boulder (or the center of the boulder or a point on the boulder), the second point may be located in a second direction offset by an angle θ1 of 20° to 170°, 30° to 150°, or 45° to 135° to the right of the first direction in the horizontal plane from the boulder. Meanwhile, the third point may be located in a third direction offset by an angle θ2 of 20° to 170°, 30° to 150°, or 45° to 135° to the left of the first direction in the horizontal plane from the boulder. θ1 and θ2 may be the same or different. By acquiring images of the boulder from three locations in this manner, a first image (front image) acquired from the first location, a second image (left side image) acquired from the second location, and a third image (right side image) acquired from the third location are obtained. The number of images is not limited to three and may be four or more. For example, in addition to the first to third images, a fourth image acquired from a location on the opposite side of the first location from the boulder (for example, a location in a direction offset by an angle of 135° to 225° to the left or right in the horizontal plane from the first direction) may be used.

[0022] The image may be captured using an imaging device capable of capturing images as digital data, such as a digital camera. The imaging device may be a camera capable of capturing monochrome images or a camera capable of capturing color images. Each image is composed of a plurality of data points arranged in a matrix of multiple rows and columns, each containing grayscale information ranging from 0 to 255. When the image is displayed on a display, the data points correspond to pixels. When the image is a color image, each data point further contains color (red, green, or blue) information. The obtained image is transferred to a computer, which will be described later. Alternatively, an analog imaging device may be used to capture the image, and the printed image may be digitized using a scanner, and the digitized image may be transferred to the computer.

[0023] (2) Scale adjustment As described above, the three image acquisition points may differ in distance and altitude from the boulder. The angles θ1 and θ2 may also differ. This may result in different scales between the images. Therefore, if the scales of the first, second, and third images differ, a scale reference may be simultaneously captured along with the boulder whose volume is to be estimated, as shown in FIG. 2A, to unify the scales between the first, second, and third images. The scale reference may be a surveying pole or any object with a known size. Alternatively, a common object that fits within all three images, even if its size is unknown, may be used as the scale reference. Examples of common objects include trees, vegetation, or other boulders near the boulder. This operation allows the first, second, and third images to be converted to the same scale, even if the scales are different. Areas with the same size, length, and area in the first, second, and third images can be represented by the same data points or number of pixels.

[0024] Furthermore, the rows and columns that make up the data points in each image are not necessarily horizontal or vertical, and if the imaging device is tilted when the image is captured, the rows and columns that make up the data points will deviate from the horizontal or vertical direction. If this deviation is significant, the tilt of the first to third images may be corrected, for example, by using a scale reference.

[0025] (3) Setting the occupied area Next, the area occupied by the boulder (occupied area) is set in each image. The occupied area is set as an area that occupies 80% to 120%, 85% to 115%, or 90% to 110% of the area of ​​the boulder displayed in each image. At this time, there is no need to consider the parts buried underground; the occupied area can be set using the parts exposed from the ground that are displayed as boulders in each image. The order in which the images for which the occupied areas are set can be determined arbitrarily.

[0026] A method for setting an occupied area (first occupied area) in the first image will be described with reference to FIG. 3. As shown in FIG. 3, the occupied area can be set by selecting multiple points on the outline of the boulder exposed from the ground, i.e., on the boundary between the boulder and the rest (i.e., the background), using an input device such as a mouse. Preferably, if the boulder in the first image is approximated as a polygon, the vertices of the polygon or their vicinity are selected. There is no limit to the number of points (selection points) selected at this time, but obtaining more selection points allows for a more accurate understanding of the boulder's outline. Although this depends on the shape of the boulder, for example, it is sufficient to obtain 5 to 20 or 6 to 10 selection points. The polygon having all of the selection points as vertices becomes the first occupied area. As described above, by acquiring multiple selection points so that the first occupancy area is 80% to 120%, 85% to 115%, or 90% to 110% of the area of ​​the boulder displayed in each image, it is possible to acquire most of the outline of the part of the boulder exposed underground when viewed from the front. Note that the selection points do not necessarily need to be selected so that they are located exactly on the boundary between the boulder and the background; a position that is off the boundary may be selected as the selection point, taking into account operational errors, image blur, etc.

[0027] Similarly, the second and third images are used to set the second and third occupied areas of the boulder, respectively. While details are omitted here, similar to setting the first occupied area, multiple selection points are selected on the boundary between the boulder and the background in the second image (Figure 4). The polygon with all of the selection points as vertices becomes the second occupied area. By acquiring multiple selection points in the second image so that the second occupied area occupies an area between 80% and 120%, between 85% and 115%, or between 90% and 110% of the boulder's area, it is possible to obtain most of the outline of the exposed portion of the left side of the boulder. A similar operation is performed on the third image to set the third occupied area (Figure 5). The second and third occupied areas obtained here are used to estimate the length of the boulder (the depth of the boulder when viewed from the front).

[0028] Because boulders are created by nature, their surfaces are usually uneven, often even in the front direction. Therefore, as shown schematically in Figures 6A and 6B, this method sets a fourth occupation area that includes the portion of the boulder that protrudes in the front direction, i.e., the protruding portion located on the first point side when observed from the front of the boulder. Specifically, using the first image, multiple locations (e.g., 5 to 20 or 6 to 10 locations) on the contour of the protruding portion are selected as selection points (Figure 7). The contour of the protruding portion is the boundary between the protruding portion and the background, or the boundary between the protruding portion and the rest of the boulder. Therefore, this protruding portion includes a portion of the first occupation area and is narrower than the first occupation area. A polygon with all of the selected points as vertices becomes the fourth occupation area. Again, the order in which the occupation areas are set is arbitrary.

[0029] (4) Construction of a virtual three-dimensional structure and calculation of its volume Next, the first to fourth occupied regions are used to construct a virtual three-dimensional body that approximates the boulder. Specifically, the areas of the first to fourth occupied regions are first calculated. The area of ​​each occupied region corresponds to the number of data points or pixels that correspond to the occupied region in each image. The area of ​​each occupied region can also be calculated from the relative ratio of the number of data points or pixels that make up the occupied region and the scale reference in each image.

[0030] Next, the average value of the areas of the first and fourth occupation regions is calculated, and the obtained average area is assumed to be the area of ​​one surface of the virtual three-dimensional structure and the surface opposite it (hereinafter, these surfaces will be referred to as the virtual top surface and the virtual bottom surface, respectively). That is, if the areas of the first and fourth occupation regions are A1 and A2, respectively, then, as shown in FIG. 8, it is assumed that the virtual three-dimensional structure has parallel virtual top and bottom surfaces that both have an average area A expressed by the following formula. Because the first and fourth occupation regions are both set from the first image acquired from the front of the boulder, the virtual three-dimensional structure has a pair of virtual top and bottom surfaces that overlap when viewed from the first direction, and it is assumed that the areas of the virtual top and bottom surfaces are both the average area A.

[0031]

number

[0032] Next, the depth D of the virtual three-dimensional structure (the distance between the virtual top surface and the virtual bottom surface in the first direction) is approximately calculated. Specifically, the depth D of the boulder from the second occupied area is calculated according to the following formula: L Here, A L is the area of ​​the second occupancy, which can be obtained from the number of data points or pixels that fall into the second occupancy. L is the length of the second occupation area in a second direction intersecting the horizontal direction. The second direction may be vertical or may be inclined at an angle of 45° to 90° from the horizontal direction. Alternatively, the length L Lis the length of the longest diagonal of the polygon that makes up the second occupied area, which is inclined at an angle of 45° to 90° from the horizontal (see Figure 4). Therefore, the second occupied area is a polygon whose height is L L and the depth seen from the first direction is D L , area is A L is assumed to be a rectangle with area A L and length L L From depth D L will be calculated.

[0033]

number

[0034] Similarly, the depth D of the boulder from the third occupied area is calculated according to the following formula: R Here, A R is the area of ​​the third occupancy region, which can be obtained from the number of data points or pixels that fall into the third occupancy region. R is the length of the third occupation area in a second direction intersecting the horizontal direction. The second direction may be vertical or may be inclined at an angle of 45° to 90° from the horizontal direction. Alternatively, the length L R is the length of the longest diagonal of the polygon that makes up the third occupied area, which is inclined at an angle of 45° to 90° from the horizontal (see Figure 5). Therefore, the third occupied area is a polygon whose height is equal to the length L R and the depth seen from the first direction is D R , area is A R is assumed to be a rectangle with area A R and length L R From depth D R will be calculated.

[0035]

number

[0036] In this method, the depth D L , D RThe average of these is used as the depth D of the virtual three-dimensional structure. That is, the depth D of the virtual three-dimensional structure is expressed by the following formula (see FIG. 8).

[0037]

number

[0038] Therefore, since the virtual three-dimensional structure has a pair of virtual top and bottom surfaces with area A separated by a depth D, its volume is expressed by the following formula.

number

[0039] The above-described method allows for the estimation of the volume of boulders from images of the boulders taken at multiple locations. However, this method does not allow for the accurate determination of the exact volume of the boulders or the volume of the portion buried in the ground. However, in general civil engineering construction management, precise volume calculations of boulders are not required. For example, the average cross-section method is often used, which calculates the volume by multiplying the average cross-sectional area of ​​two measurement points on the exposed portion of the boulder by the distance between them. Considering this, this method can be said to be an effective method for estimating the volume of objects such as boulders while meeting general civil engineering construction management standards.

[0040] Furthermore, in conventional methods, obtaining the cross-sectional area at two measurement points requires workers on-site to measure the height and circumference of boulders using surveying equipment, which is dangerous and extremely inefficient. In contrast, our method allows us to estimate the volume of boulders in a very short time by simply acquiring and analyzing images of the boulders from three locations without using conventional surveying equipment. Furthermore, by capturing images of objects using unmanned vehicles or unmanned aerial vehicles equipped with imaging devices, work safety can be dramatically improved. This allows us to estimate the volume of large amounts of boulders in a short time without placing a heavy burden on workers or exposing them to the risks associated with on-site surveying. This not only improves safety and work efficiency, but also significantly contributes to saving human resources.

[0041] 2. Variations As described above, this method acquires a part of the object, i.e., a protruding part protruding toward the first point, as the fourth occupancy area. However, depending on the image, it may not be easy to set the fourth occupancy area. For this reason, image processing may be performed on the first image as necessary.

[0042] Figure 9 shows a flowchart of this method, including image processing. As shown in Figure 9, image processing is performed after the first occupation area is set, and after image processing, the fourth occupation area is set. Specifically, as shown in Figure 10, the first occupation area is set according to the method described above. Then, the portion not included in the first occupation area is deleted. As a result, an image consisting of the boulders included in the first occupation area and the background is obtained.

[0043] The resulting image is then binarized, as shown in Figures 10 and 11. There are no restrictions on the binarization method; known methods such as the Niblack method, the Sauvola method, the p-tile method, and discriminant analysis can be used. The threshold gradation for binarization can also be set arbitrarily, taking into account the overall gradation of the first image, for example, within a range from 60 to 200 gradations. This results in the first occupancy area being displayed as data points or pixels with gradations of 0 and 1. Because sharp edges, i.e., the edges of boulders, typically display with relatively high gradations, the binarization process prioritizes the display of edge portions. Therefore, by selecting a selection point on or near the gradation 1 area obtained by the binarization process, a fourth occupancy area including the protruding portion can be easily defined. Note that while a background is depicted in Figure 11, this background is merely a convenient background for indicating the gradation 1 area displayed in white; it is not a background included in the first image.

[0044] Alternatively, instead of binarization, edge detection may be performed on the first occupied area. In this process, a first-order differential filter is applied to the data points or pixels that make up the first occupied area. Known first-order differential filters, such as a Sobel filter, Prewitt filter, Gaussian filter, or Laplacian filter, can be used. For example, when using a Sobel or Prewitt filter, the grayscale values ​​of the nine data points or pixels surrounding the data point or pixel of interest are multiplied by a constant. This process is performed on all data points or pixels. The grayscale values ​​of the resulting set of data points or pixels are calculated in the x and y directions, and areas with large grayscale changes are detected as edges. For example, areas with a grayscale difference of 10 or more between adjacent data points may be considered edges, or areas with a grayscale difference of 20 or more may be considered edges. Because edge detection allows preferential extraction of the edge of the boulder, a fourth occupied area including protruding portions can be easily defined by selecting a selection point on or near the extracted edge.

[0045] Alternatively, edge detection may be performed after binarization.

[0046] Furthermore, when selecting a selection point, the first occupation area that has been subjected to binarization or edge detection processing may be superimposed on the actual image of the first occupation area (i.e., the first occupation area before binarization or edge detection processing). This operation allows the selection point to be selected on the area of ​​gradation 1 or the detected edge portion while referring to the actual image, making it possible to set the fourth occupation area more accurately and easily.

[0047] 2. Program, computer-readable storage medium, and computer Another embodiment of the present invention is a program for estimating the volume of an object (volume estimation program). The volume estimation program may include not only machine language code such as that generated by a compiler, but also high-level language code executed by a server using an interpreter or the like.

[0048] A computer-readable recording medium on which this volume estimation program is recorded also constitutes an embodiment of the present invention. Examples of computer-readable recording media include magnetic media such as hard disks, flexible disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, magneto-optical media such as floptical disks, and hardware devices configured to store and execute the volume estimation program, such as ROMs, RAMs, and flash memories.

[0049] Another embodiment of the present invention is a computer having the volume estimation program installed therein. The computer is a device having communication and calculation functions, and may be a notebook or desktop information processing device, or may be a mobile communication terminal such as a tablet computer.

[0050] As shown in the block diagram of FIG. 12 , the computer 100 includes a control unit 102 that controls the operation of the computer 100, as well as an input unit 104, an output unit 106, a transceiver unit 108, a memory unit 110, an audio output unit 112, an input port 114, and other components controlled by the control unit 102. The memory unit 110 stores a volume estimation program and other programs, along with basic application programs for operating the computer 100. The control unit 102 includes a processor such as a central processing unit (CPU), and controls various processes executed by the computer 100 by running the basic application programs and volume estimation programs stored in the memory unit 110. This enables volume estimation of an object according to the present method. The input unit 104 is a user interface used to input commands and information to the computer 100, and typically includes a keyboard, a touch panel, a mouse, or a combination thereof. The output unit 106 provides various data stored in the memory unit 110 as images or printed matter, and is an output device such as a display device, such as a liquid crystal display device or an organic electroluminescence display device, or a printer. When a touch panel is used as the input unit 104, the touch panel can be placed on the display device. The transmitter / receiver 108 has a function of communicating with external devices such as an imaging device via a network. The audio output unit 112 is a speaker that has a function of generating various sounds. The input port 114 is a wired interface that can be physically connected to a storage medium such as a memory card, thereby making it possible to connect the storage medium in which images are stored in the imaging device to the computer 100.

[0051] The volume estimation program is installed in the storage unit 110 from a computer-readable medium. Alternatively, the volume estimation program may be downloaded to the storage unit 110 from a network. Alternatively, the volume estimation program may be configured to run on a network using a browser installed in the computer 100.

[0052] The above-described embodiments of the present invention can be combined as appropriate as long as they are not mutually inconsistent. A product in which a person skilled in the art appropriately adds or deletes components or modifies the design based on each embodiment is also included within the scope of the present invention as long as it includes the gist of the present invention.

[0053] Even if there are other effects and advantages different from those brought about by the above-described embodiments, those that are clear from the description in this specification or that can be easily predicted by a person skilled in the art are naturally understood to be brought about by the present invention. [Explanation of symbols]

[0054] 100: Computer, 102: Control unit, 104: Input unit, 106: Output unit, 108: Transmitter / receiver unit, 110: Storage unit, 112: Audio output unit, 114: Input port

Claims

1. acquiring a first image, a second image, and a third image of the object from a first point on a first direction from the object, a second point to the right of the first direction, and a third point to the left of the first direction, respectively; setting a first occupation area, a second occupation area, and a third occupation area occupying 80% or more and 120% or less of an area of ​​the object in each of the first image to the third image; setting a fourth occupation area in the first image, the fourth occupation area including a part of the object located on the first point side and being smaller than the first occupation area; and determining a volume V of the object according to the formula: [Equation 1] A 1 and A 2 are the areas of the first and fourth occupation regions, respectively; D L and D R are expressed by the following formulas, [Equation 2] A L and A R are the areas of the second and third occupation regions, respectively; L L and L R and are the lengths of the second and third occupied regions in a second direction intersecting the horizontal direction, respectively.

2. The method of claim 1 , wherein the second direction is a vertical direction.

3. the second occupation area and the third occupation area are both polygonal; L L is the length of the longest diagonal line of the polygon constituting the second occupation area, the diagonal line being inclined at an angle of 45° to 90° from the horizontal, L R The method according to claim 1 , wherein is the length of the longest diagonal of the polygon constituting the third occupancy area that is inclined at an angle of 45° to 90° from the horizontal.

4. each of the first image, the second image, and the third image is acquired to include the object and a scale reference; The method of claim 1 , further comprising: utilizing the scale reference to unify the scales of the first image, the second image, and the third image.

5. the second point is located in a direction between 20° and 170° to the right of the first direction; The method of claim 1 , wherein the third point is located in a direction between 20° and 170° to the left of the first direction.

6. The method of claim 1 , further comprising: after setting the first occupation area and before setting the fourth occupation area, performing a binarization process and / or an edge extraction process on the first occupation area.

7. The method according to claim 6 , further comprising superimposing the first occupation area before and after the binarization process and / or the edge extraction process, before setting the fourth occupation area.

8. The processing device receiving an instruction to set a first occupancy area, a second occupancy area, and a third occupancy area occupying 80% to 120% of an area of ​​the object in a first image, a second image, and a third image of the object acquired from a first point on a first direction from the object, a second point to the right of the first direction, and a third point to the left of the first direction, respectively; receiving an instruction to set a fourth occupation area in the first image, the fourth occupation area including a part of the object located on the first point side and being smaller than the first occupation area; calculating an area of ​​the fourth occupation area from the first occupation area; calculating the lengths of the second and third occupancy areas in a second direction intersecting the horizontal direction; and determining a volume V of the object according to the following formula: [Equation 3] A 1 and A 2 are the areas of the first and fourth occupation regions, respectively; D L and D R are expressed by the following formulas, [Equation 4] A L and A R are the areas of the second and third occupancies, respectively; L L and L R are the lengths of the second and third occupancy regions, respectively.

9. The computer program product according to claim 8 , wherein the second direction is a vertical direction.

10. the second occupation area and the third occupation area are both polygonal; L L is the length of the longest diagonal line of the polygon constituting the second occupation area, the diagonal line being inclined at an angle of 45° to 90° from the horizontal, L R is the length of the longest diagonal of the polygon that constitutes the third occupation area, the diagonal being inclined at an angle of 45° to 90° from the horizontal.

11. 9. The program of claim 8, further configured to cause the processing device to unify the scales of the first image, the second image, and the third image using a scale reference included in each of the first image, the second image, and the third image.

12. The program according to claim 8 , further configured to cause the processing device to perform a binarization process and / or an edge extraction process on the first image.

13. The program according to claim 12 , further configured to cause the processing device to superimpose the first occupation area before and after the binarization process and / or the edge extraction process.

14. A computer-readable storage medium on which the program according to claim 8 is recorded.

15. A computer having the program according to claim 8 installed thereon.

Images