JP2011127932A - Device, method and program for measuring three-dimensional shape, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To highly accurately measure a three-dimensional shape of a moving object. <P>SOLUTION: The device for measuring the three-dimensional shape includes a video input I/F part which acquires phase image data obtained by phase-shifting reflection patterns from the moving object on which a phase pattern is projected and from a back screen and by imaging the patterns, an image characteristic quantity extracting part 201 which detects an edge from the phase image data and extracts image characteristic quantity data according to the strength of the edge, a phase pattern generating part 203 which generates phase pattern data of which the grating width is adjusted on the basis of an image characteristic quantity data row for one phase period extracted by the image characteristic quantity extracting part 201, a phase distribution image generating part 212 which generates phase distribution image data based on a phase image data row for one phase period, a phase connecting part 213 which generates continuous phase distribution image data by performing the phase connection of the phase distribution image data, and a three-dimensional shape generating part 214 which generates three-dimensional shape data on the moving object based on the continuous phase distribution image data. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a three-dimensional shape measuring apparatus, a three-dimensional shape measuring method, a three-dimensional shape measuring program, and a recording medium.

  A three-dimensional shape measurement technique is known in which a grid-like phase pattern is projected onto a measurement target object, and a projection pattern that is a grid pattern is imaged to measure the three-dimensional shape of the measurement target object. This phase pattern is generally a uniform lattice pattern, but a lattice projection shape measuring device that projects a phase pattern of a lattice pattern whose pitch periodically changes depending on the position is also known (for example, , See Patent Document 1).

Japanese Patent No. 3536097

However, when the phase pattern is a uniform lattice pattern, there is a problem that the measurement accuracy is lowered at a portion where the height (depth) gradient of the measurement target object is steep. Moreover, although the lattice projection shape measuring apparatus described in Patent Document 1 is to project by changing the phase pattern, since the projection pattern is determined according to the position of the object, the measurement target object is a stationary object. Is assumed. Therefore, this lattice projection shape measuring apparatus is difficult to apply to measuring the three-dimensional shape of a moving object.
Therefore, the present invention has been made to solve the above problem, and is a three-dimensional shape measuring apparatus, a three-dimensional shape measuring method, and a three-dimensional shape measurement capable of measuring a three-dimensional shape of a moving object with high accuracy. It is an object to provide a program and a recording medium.

In order to solve the above problems, one aspect of the present invention provides the following means [1]-[6].
[1] A phase image data acquisition unit that acquires phase image data obtained by imaging the measurement target object onto which the phase pattern is projected and the reflection pattern from the back screen by shifting the phase in time series, and the acquisition An image feature quantity extraction unit that detects an edge corresponding to the phase pattern from the obtained phase image data and extracts image feature quantity data corresponding to the strength of the edge; and the phase 1 extracted by the image feature quantity extraction unit A phase pattern generation unit that generates phase pattern data in which the lattice width is adjusted based on an image feature amount data sequence for a period, and a phase based on a phase image data sequence for one phase acquired by the phase image data acquisition unit Phase distribution image generation unit for generating distribution image data, and phase for generating continuous phase distribution image data by performing phase connection of the generated phase distribution image data A three-dimensional shape comprising: a connection unit; and a three-dimensional shape generation unit that generates three-dimensional shape data of the measurement target object according to a triangulation method based on the generated continuous phase distribution image data measuring device.
[2] In the three-dimensional shape measuring apparatus according to [1], an image feature quantity data sequence for one phase extracted by the image feature quantity extraction unit and one phase cycle before the image feature quantity data sequence An image feature quantity comparison unit that generates a predicted image feature quantity data sequence based on the image feature quantity data sequence of the image feature quantity data sequence, and the phase pattern generation unit includes the predicted image feature quantity data generated by the image feature quantity comparison unit A three-dimensional shape measuring apparatus, characterized by generating phase pattern data in which a lattice width is adjusted based on a column.
[3] A phase image data acquisition step of acquiring phase image data obtained by imaging the measurement target object onto which the phase pattern is projected and the reflection pattern from the back screen by shifting the phase in time series, and the acquisition Detecting an edge corresponding to the phase pattern from the phase image data obtained, and extracting image feature amount data corresponding to the strength of the edge; and the phase 1 extracted in the image feature amount extraction step A phase pattern generation step of generating phase pattern data in which the grating width is adjusted based on an image feature amount data sequence for a period, and a phase image data sequence for one phase acquired in the phase image data acquisition step A phase distribution image generation step for generating phase distribution image data based on the phase distribution image data, and the generated phase distribution image A phase connection step of generating phase connection image data by performing phase connection of image data, and generating three-dimensional shape data of the measurement target object according to a triangulation method based on the generated continuous phase distribution image data And a three-dimensional shape generation step.
[4] In the three-dimensional shape measurement method described in [3] above, an image feature quantity data sequence for one phase extracted in the image feature quantity extraction step and a phase one cycle before the image feature quantity data sequence And an image feature amount comparison step for generating a predicted image feature amount data sequence based on the image feature amount data sequence, and the phase pattern generation step includes the predicted image feature amount generated in the image feature amount comparison step. A three-dimensional shape measurement method, comprising: generating phase pattern data in which a lattice width is adjusted based on a data string.
[5] A phase image data acquisition unit that acquires phase image data obtained by imaging the measurement object on which the phase pattern is projected and the reflection pattern from the back screen by shifting the phase in time series; Detecting an edge corresponding to the phase pattern from the acquired phase image data, and extracting image feature amount data corresponding to the strength of the edge; and the image feature amount extraction unit extracts A phase pattern generation unit that generates phase pattern data in which the grating width is adjusted based on the image feature amount data sequence for one phase of the phase, and a phase image data sequence for one phase acquired by the phase image data acquisition unit. A phase distribution image generation unit that generates phase distribution image data based on the phase connection between the generated phase distribution image data and continuous phase distribution image data. And a three-dimensional shape generation unit that generates three-dimensional shape data of the measurement target object in accordance with a triangulation method based on the generated continuous phase distribution image data. 3D shape measurement program.
[6] A phase image data acquisition unit that acquires phase image data obtained by imaging the measurement target object onto which the phase pattern is projected and the reflection pattern from the back screen by shifting the phase in time series; Detecting an edge corresponding to the phase pattern from the acquired phase image data, and extracting image feature amount data corresponding to the strength of the edge; and the image feature amount extraction unit extracts A phase pattern generation unit that generates phase pattern data in which the grating width is adjusted based on the image feature amount data sequence for one phase of the phase, and a phase image data sequence for one phase acquired by the phase image data acquisition unit. A phase distribution image generation unit that generates phase distribution image data based on the phase connection between the generated phase distribution image data and continuous phase distribution image data. And a three-dimensional shape generation unit that generates three-dimensional shape data of the measurement target object in accordance with a triangulation method based on the generated continuous phase distribution image data. A computer-readable recording medium on which a three-dimensional shape measurement program is recorded.

  According to the present invention, the three-dimensional shape of a moving object can be measured with high accuracy.

1 is a schematic overall configuration diagram of a three-dimensional shape measurement system to which a three-dimensional shape measurement device according to a first embodiment of the present invention is applied. It is a block diagram which shows the schematic hardware constitutions of a three-dimensional shape measuring apparatus among the three-dimensional shape measuring systems in the embodiment. FIG. 2 is a block diagram showing a schematic functional configuration of a three-dimensional shape measuring apparatus in the same embodiment. In the embodiment, it is the figure which showed typically the phase image data which the imaging device imaged, and the strength of the edge which an image feature-value extraction part extracts from the phase image data in correlation. It is a flowchart which shows the process sequence of the phase pattern data generation process of the three-dimensional shape measuring apparatus in the embodiment. In the embodiment, it is the figure which showed typically a mode that a grating | lattice was newly added to a grating | lattice pattern. In the embodiment, it is the figure which showed typically a mode that the grating | lattice was deleted from a grating | lattice pattern. It is a flowchart which shows the process sequence of the three-dimensional shape measurement process of the three-dimensional shape measuring apparatus in the embodiment. It is a figure for demonstrating calculating | requiring the three-dimensional coordinate value of a moving object in the same embodiment. It is a block diagram which shows the rough function structure of the three-dimensional shape measuring apparatus which is 2nd Embodiment of this invention. It is a flowchart which shows the process sequence of the phase pattern data generation process of the three-dimensional shape measuring apparatus in the embodiment.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
[First Embodiment]
FIG. 1 is a schematic overall configuration diagram of a three-dimensional shape measurement system to which a three-dimensional shape measurement apparatus according to a first embodiment of the present invention is applied. As shown in the figure, the three-dimensional shape measurement system 1 includes a projection device 10, a three-dimensional shape measurement device 20, an imaging device 30, and a display device 40. In addition, the figure shows a state where the moving object MO, which is the object to be measured, is positioned in front of the back screen BS. Note that the moving object MO is an object having a three-dimensional shape, but in the present embodiment, it is schematically represented in order to simplify the drawing.

  The projection device 10 is a device that receives phase pattern data supplied from the three-dimensional shape measurement device 20 and projects image light of a phase pattern. The projection device 10 is, for example, a projection type projector device. The three-dimensional shape measuring apparatus 20 receives phase image data that has been captured with a phase shifted by a predetermined phase difference in time series from the imaging apparatus 30 and generates phase pattern data to be projected in the next cycle. And supplied to the projection apparatus 10. The three-dimensional shape measuring apparatus 20 generates three-dimensional shape data from the acquired phase image data, stores the three-dimensional shape data in the own apparatus, and outputs the data to the display device 40 as a video signal.

  The imaging device 30 images the reflected light from the phase pattern image light projected onto the moving object MO and the back screen BS by shifting the phase with a predetermined phase difference in a time series manner, thereby obtaining a phase image. The data is sequentially supplied to the three-dimensional shape measuring apparatus 20 as data. The imaging device 30 is a camera device that can capture images in frame units, and is, for example, a digital camera or a digital video camera. The predetermined phase difference is, for example, π / 2, π / 3, π / 4 (radian), etc., with -π (radian) to π (radian) as one cycle. The display device 40 is a monitor device that displays an image of three-dimensional shape data based on the video signal supplied from the three-dimensional shape measurement device 20.

In the three-dimensional shape measurement system 1, the projection device 10 is fixedly installed in a direction in which image light can be projected within a specific range in which the moving object MO moves in front of the back screen BS. In addition, the imaging device 30 is fixedly installed in a direction that allows imaging within the specific range.
In the three-dimensional shape measurement system 1, the projection device 10, the three-dimensional shape measurement device 20, and the imaging device 30 are temporally synchronized.

  FIG. 2 is a block diagram showing a schematic hardware configuration of the three-dimensional shape measuring apparatus 20 in the three-dimensional shape measuring system 1. As shown in the figure, the three-dimensional shape measuring apparatus 20 includes, as its hardware configuration, a video input interface (I / F) unit 21, a control unit 22, a storage unit 23, and a video output I / F unit 24. And a display I / F unit 25.

  The video input I / F unit 21 is a video input interface that sequentially captures phase image data supplied in time series from the imaging device 30 and supplies the phase image data to the control unit 22. The control unit 22 extracts image feature data from the phase image data and generates phase pattern data to be projected in the next cycle, or generates phase distribution image data from the phase image data to perform phase connection, It is a processing unit that generates original shape data. The control unit 22 includes a CPU (Central Processing Unit) (not shown).

  The storage unit 23 stores image feature amount data extracted by the control unit 22, stores phase image data captured by the control unit 22, and stores three-dimensional shape data generated by the control unit 22. Device. The storage unit 23 is, for example, a memory or a hard disk. The video output I / F unit 24 is a video output interface that supplies the phase pattern data generated by the control unit 22 to the projection apparatus 10. The display I / F unit 25 is a display output interface for displaying the three-dimensional shape data generated by the control unit 22 on the display device 40.

  As shown in FIG. 2, the three-dimensional shape measuring apparatus 20 is an information processing apparatus such as a personal computer or a board computer provided with an image input / output interface. That is, in the present embodiment, the three-dimensional shape measuring apparatus 20 can be configured using a general-purpose computer or the like.

FIG. 3 is a block diagram showing a schematic functional configuration of the three-dimensional shape measuring apparatus 20. As shown in the figure, the three-dimensional shape measurement apparatus 20 includes, as its functional configuration, an image feature amount extraction unit 201, an image feature amount storage unit 202, a phase pattern generation unit 203, a phase image storage unit 211, A phase distribution image generation unit 212, a phase connection unit 213, a three-dimensional shape generation unit 214, and a three-dimensional shape storage unit 215 are included.
The image feature quantity extraction unit 201, the phase pattern generation unit 203, the phase distribution image generation unit 212, the phase connection unit 213, and the three-dimensional shape generation unit 214 are functions that the control unit 22 has. The image feature amount storage unit 202, the phase image storage unit 211, and the three-dimensional shape storage unit 215 are functions that the storage unit 23 has.

  When receiving the supply of the phase image data, the image feature amount extraction unit 201 analyzes the phase image data and extracts predetermined image feature amount data. The image feature amount storage unit 202 stores the image feature amount data extracted by the image feature amount extraction unit 201. The phase pattern generation unit 203 reads an image feature amount data string for one cycle from the image feature amount storage unit 202, and generates phase pattern data to be projected in the next cycle. The phase image storage unit 211 stores the phase image data supplied from the imaging device 30. The phase distribution image generation unit 212 reads a phase image data sequence for one period from the phase image storage unit 211, obtains a phase distribution in the phase image data sequence, and generates phase distribution image data. From this phase distribution, it can be seen that the relative luminance difference at the same position in the phase image data string shows a change only by the phase difference of the projected pattern. The phase connection unit 213 performs phase connection of the phase distribution image data to generate continuous phase distribution image data. The three-dimensional shape generation unit 214 calculates a three-dimensional coordinate value of the moving object MO based on the continuous phase distribution image data and generates three-dimensional shape data. The three-dimensional shape storage unit 215 stores three-dimensional shape data.

  The three-dimensional shape measuring apparatus 20 shown in FIG. 3 processes in real time the process from receiving the supply of phase image data to outputting phase pattern data to be projected in the next cycle. A process of generating and outputting three-dimensional shape data after the data is stored in the phase image storage unit 211 is performed by batch processing.

Next, the image feature amount data will be described. FIG. 4 is a diagram schematically illustrating the phase image data captured by the imaging device 30 and the edge strength extracted from the phase image data by the image feature amount extraction unit 201 in association with each other. In the figure, phase image data 4 is image data of a phase image obtained by imaging the back screen BS and the moving object MO in front of the imaging device 30. The phase image data 4 includes a phase pattern reflection pattern 4a projected onto the back screen BS and a phase pattern reflection pattern 4b projected onto the moving object MO.
The phase image data 4 in the figure is an example in which the lattice pattern is equally spaced, and the lattice spacing of the reflection pattern 4a from the back screen BS which is a plane is substantially equal.
On the other hand, in the phase image data 4, when the moving object MO has undulations in the depth direction (axial direction orthogonal to both axes XY in the figure), the gratings of the reflection pattern 4b from the moving object MO are not equally spaced. That is, as the rate of change of the depth of the moving object MO increases, the position of the deformed grating on the reflection pattern from the moving object MO is greatly separated from the position of the grating on the reflection pattern when the moving object MO does not exist. . In the present embodiment, the amount of displacement of the lattice is extracted as an image feature amount.

  Specifically, when receiving the phase image data 4, the image feature amount extraction unit 201 detects an edge and maps the strength of the edge in a direction along the lattice pattern. That is, mapping is performed in the X-axis direction in FIG. In the extraction of the edge strength, the image feature amount extraction unit 201 uses the edge strength of the grid of the reflection pattern 4a (broken line in the graph in the figure) and the strength of the grid edge of the reflection pattern 4b (in the figure). The solid line of the graph) and the strength of the edge of the contour of the moving object MO itself (the shaded portion of the graph in the figure) are extracted. Among these three types of edge strengths, the edge strength of the contour of the moving object MO itself is smaller than the strength of the edge of the grid, so the image feature quantity extraction unit 201 determines the strength of the edge of the grid and the moving object MO. Applying a threshold value that is the strength between the edge strength of the contour of itself to exclude the strength of the edge of the contour of the moving object MO itself. Thereby, the image feature extraction unit 201 extracts the strength of the edge derived only from the lattice pattern. Note that the threshold level can be arbitrarily adjusted.

  The image feature amount extraction unit 201 calculates a difference value between the edge position of the reflection pattern from the back screen BS and the edge position of the reflection pattern from the moving object MO, and outputs the difference value as image feature amount data. In FIG. 4, the image feature quantity data of the mth grid (m is an integer of 0 or more) from the origin position is d (m).

  Next, the operation of the three-dimensional shape measurement system 1 in the present embodiment will be described mainly focusing on the operation of the three-dimensional shape measurement apparatus 20. The three-dimensional shape measurement system 1 performs calibration for various parameters before starting measurement. For example, the distance between the projection device 10 and the imaging device 30, the focal length of the projection device 10, and the focal length of the imaging device 30 are measured. Further, the three-dimensional shape measuring apparatus 20 outputs phase pattern data that is a lattice pattern at equal intervals, projects the image light of the phase pattern from the projection apparatus 10 onto the back screen BS, and images the reflection pattern on the imaging apparatus 30. Thus, phase image data is acquired, the edge of each lattice is detected, and the edge number (m) and the position of the edge (position on the X-axis) are acquired in association with each other.

  When the three-dimensional shape measurement system 1 starts measurement, the projection device 10 starts projection, the imaging device 30 starts imaging, and the three-dimensional shape measurement device 20 starts capturing phase image data. However, the projection device 10, the imaging device 30, and the three-dimensional shape measurement device 20 operate in a linked manner so as to synchronize at a cycle of shifting the phase.

The operation of the phase pattern data generation process of the three-dimensional shape measuring apparatus 20 in this embodiment will be described. FIG. 5 is a flowchart showing a processing procedure of phase pattern data generation processing of the three-dimensional shape measuring apparatus 20. In step S <b> 101, when one frame of phase image data is supplied from the imaging device 30, the video input I / F unit 21 captures this and supplies it to the image feature amount extraction unit 201 and also stores it in the phase image storage unit 211. Supply.
In step S <b> 102, the image feature amount extraction unit 201 extracts image feature amount data from the supplied phase image data for one frame and stores it in the image feature amount storage unit 202. Specifically, the image feature quantity extraction unit 201 detects a grid edge from the supplied phase image data for one frame, and maps the strength of the edge in a direction along the grid pattern. The image feature amount extraction unit 201 calculates the difference between the position of each edge obtained by mapping and the position of the edge associated with the grid edge number (m) acquired in the calibration. Certain image feature data d (m) is calculated and stored in the image feature data storage unit 202.

  Next, in step S103, the image feature amount extraction unit 201 determines whether or not image feature amount data for one cycle has been extracted, and determines that image feature amount data for one cycle has been extracted (S103). : YES) proceeds to the process of step S104, and if it is determined that the image feature amount data for one cycle has not been extracted (S103: NO), the process returns to step S101.

In step S <b> 104, the phase pattern generation unit 203 reads an image feature amount data sequence that is image feature amount data for one cycle from the image feature amount storage unit 202, and generates phase pattern data to be projected in the next cycle. . Specifically, the phase pattern generation unit 203 calculates an average value d _cycle (m) of image feature amount data for one period in the m-th lattice. Then, when the average value d _cycle (m) is larger than a predetermined threshold value Th, the phase pattern generation unit 203 estimates that the gradient in the depth direction of the moving object MO is large, as shown in FIG. A lattice is added between adjacent lattice rows S1 including the mth lattice 6. At that time, the phase pattern generation unit 203 makes the respective lattice widths of the lattice row S2 obtained by adding the lattice to the lattice row S1 have equal intervals. The phase pattern generation unit 203 assigns the edge numbers of the lattice array S2 to m_1, m_2, etc. derived from m, for example.
On the other hand, when the average value d _cycle (m) is equal to or smaller than the threshold value Th, the phase pattern generation unit 203 estimates that the gradient in the depth direction of the moving object MO is small, and the m-th lattice as shown in FIG. The grids before and after 7 are deleted from the grid row S3. At that time, the phase pattern generation unit 203 makes the lattice widths of the lattice row S4 obtained by deleting the lattice from the lattice row S3 equal intervals. The phase pattern generation unit 203 leaves the number of the edge of the lattice row S4, for example, m, which is the center number from m−1, m, and m + 1.

  That is, the phase pattern generation unit 203 determines the gradient of the moving object MO in the depth direction based on the difference between the position of the edge of the projection pattern deformed by the shape of the moving object MO and the position of the edge of the projection pattern on the back screen BS. The phase pattern data with a narrowed grid width is generated at a location where the gradient in the depth direction of the moving object MO is large, and the phase at which the grid width is increased at a location where the gradient in the depth direction of the moving object MO is small. Generate pattern data. Thereby, the three-dimensional shape measurement system 1 can measure the three-dimensional shape of the moving object MO with high accuracy.

Returning to FIG. 5, in step S <b> 105, the video output I / F unit 24 transmits the phase pattern data generated by the phase pattern generation unit 203 to the projection device 10.
Next, in step S106, when the control unit 22 determines that a predetermined end condition (specified time or number of specified processing frames) is satisfied, or when an end instruction is supplied from the outside (S106: YES), The process of the flowchart ends. On the other hand, if it is determined that the predetermined end condition is not satisfied, or if no end instruction is supplied from the outside (S106: NO), the process returns to step S101.

Next, the operation of the 3D shape measurement process of the 3D shape measurement apparatus 20 will be described. FIG. 8 is a flowchart showing the processing procedure of the three-dimensional shape measurement process of the three-dimensional shape measurement apparatus 20. In step S <b> 201, the control unit 22 stores the phase image data for one frame supplied from the video input I / F unit 21 in the phase image storage unit 211.
Next, in step S202, the control unit 22 determines whether or not the phase image data for one cycle has been stored, and if it is determined that the phase image data for one cycle has been stored (S202: YES), the step is performed. Moving to the processing of S203, when it is determined that the phase image data for one cycle is not stored (S202: NO), the processing returns to the processing of step S101 of FIG.

In step S203, the phase distribution image generation unit 212 reads a phase image data sequence that is phase image data for one period from the phase image storage unit 211, obtains a phase distribution in the phase image data sequence, and obtains the phase distribution image data. Generate.
Next, in step S204, the phase connection unit 213 performs phase connection of the phase distribution image data to generate continuous phase distribution image data. Here, since the phase value of the phase distribution image data is a value between −π (radian) and π (radian), if there is a phase difference of 2π (radian) between adjacent phases, this should be taken into consideration. Connect the phases. As the phase connection method, a known neighborhood connection method, minimum tree search method, energy minimization method, or the like can be applied.

Next, in step S205, the 3D shape generation unit 214 calculates 3D coordinate values of the moving object MO based on the continuous phase distribution image data, generates 3D shape data, and stores the 3D shape data in the 3D shape storage unit 215. Remember.
Specifically, as shown in FIG. 9, the line-of-sight angle α from the reference point Co of the imaging device 30 is obtained based on the image coordinates, and the expected angle β from the reference point Po of the projection device 10 is calculated based on the phase value. Therefore, the three-dimensional shape generation unit 214 uses the distance L between the projection apparatus 10 and the imaging apparatus 30 that has been determined in advance by calibration, so that the three-dimensional shape of the moving object MO can be calculated from the principle of triangulation. Coordinates can be obtained. The three-dimensional shape generation unit 214 performs the calculation for all the pixels included in one frame, generates three-dimensional shape data of the moving object MO, and stores it in the three-dimensional shape storage unit 215.

Returning to FIG. 8, in step S <b> 206, the display I / F unit 25 outputs the three-dimensional shape data generated by the three-dimensional shape generation unit 214 to the display device 40.
Next, in step S207, when the control unit 22 determines that a predetermined end condition (specified time or number of specified processing frames) is satisfied, or when an end instruction is supplied from the outside (S207: YES), The process of the flowchart ends. On the other hand, if it is determined that the predetermined end condition is not satisfied, or if no end instruction is supplied from the outside (S207: NO), the process returns to step S101 in FIG.

[Second Embodiment]
FIG. 10 is a block diagram showing a schematic functional configuration of the three-dimensional shape measuring apparatus according to the second embodiment of the present invention. In describing this block diagram, the same components as those of the above-described three-dimensional shape measuring apparatus 20 in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
As shown in the figure, the three-dimensional shape measurement apparatus 20a includes a phase pattern generation unit 203a instead of the phase pattern generation unit 203, as compared with the three-dimensional shape measurement apparatus 20 of the first embodiment. A comparison unit 204 and an image feature amount sequence storage unit 205 are further included.
The phase pattern generation unit 203 a and the image feature amount comparison unit 204 are functions that the control unit 22 has. Further, the image feature amount sequence storage unit 205 is a function of the storage unit 23.

The image feature amount comparison unit 204 reads an image feature amount data sequence for one cycle from the image feature amount storage unit 202 and also reads an image feature amount data sequence of the previous cycle from the image feature amount sequence storage unit 205. Are read, and the read image feature value data sequence and the previous cycle image feature value data sequence are compared to generate a predicted image feature value data sequence. Then, the image feature amount comparison unit 204 stores the image feature amount data sequence for one cycle read from the image feature amount storage unit 202 in the image feature amount sequence storage unit 205.
The image feature amount sequence storage unit 205 stores the supplied image feature amount data sequence, and outputs it as a previous period image feature amount data sequence by reading control from the image feature amount comparison unit 204. The image feature quantity storage unit 205 is a FIFO storage unit.
The phase pattern generation unit 203a generates phase pattern data to be projected in the next cycle based on the predicted image feature amount data string supplied from the image feature amount comparison unit 204.

  The three-dimensional shape measuring apparatus 20a shown in FIG. 10 performs processing in real time from receiving phase image data until outputting phase pattern data to be projected in the next cycle, while phase images for one cycle. A process of generating and outputting three-dimensional shape data after the data is stored in the phase image storage unit 211 is performed by batch processing.

  Next, the operation of the phase pattern data generation process of the three-dimensional shape measuring apparatus 20a in this embodiment will be described. FIG. 11 is a flowchart showing a processing procedure of phase pattern data generation processing of the three-dimensional shape measuring apparatus 20a. In describing this flowchart, the same processing steps as the processing steps of the three-dimensional shape measuring apparatus 20 in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

  In step S104a, the image feature amount comparison unit 204 reads an image feature amount data sequence for one cycle from the image feature amount storage unit 202, and the image feature amount data of the previous cycle from the image feature amount sequence storage unit 205. A previous-period image feature quantity data sequence, which is a sequence, is read out, and the read-out image feature quantity data sequence and the previous-period image feature amount data sequence are compared to generate a predicted image feature quantity data sequence.

Specifically, the image feature quantity comparison unit 204 calculates the average value d _cycle (m) of the image feature quantity data for one period in the m-th lattice and one period in the period _immediately before the current time. Based on the average value d _{cycle_prev} (m) of the image feature amount data, a predicted image feature amount data sequence d _{cycle_next} (m) is calculated. In this calculation process, the calculation method of the image feature amount comparison unit 204 differs depending on whether the lattice pattern is added or deleted in the previous cycle, or whether the lattice pattern is added or deleted.
That is, when neither the grid pattern is added nor deleted in the previous cycle, the image feature quantity comparison unit 204 calculates the predicted image feature quantity data sequence d _{cycle_next} (m) using Expression (1).

When a lattice pattern is added or deleted in the previous cycle, the image feature amount comparison unit 204 calculates a predicted image feature amount data string d _{cycle_next} (m) using Expression (2).

  Next, the image feature amount comparison unit 204 stores the image feature amount data sequence for one cycle read from the image feature amount storage unit 202 in the image feature amount sequence storage unit 205.

Next, in step S <b> 104 b, the phase pattern generation unit 203 a is the same as the process of step S _< b _> 104 in the first embodiment based on the predicted image feature quantity data sequence d _{cycle_next} (m) supplied from the image feature quantity comparison unit 204. Through this process, phase pattern data to be projected in the next period is generated.
Specifically, the phase pattern generation unit 203a, when the predicted image feature value data string d _{cycle_next} (m) is larger than a predetermined threshold Th _next , between adjacent grid strings including the mth grid. Add a grid to At that time, the phase pattern generation unit 203a makes the respective lattice widths of the new lattice rows obtained by adding the lattices to the lattice rows become equal intervals. The phase pattern generation unit 203 assigns the edge numbers of the lattice array S2 to m_1, m_2, etc. derived from m, for example.
On the other hand, when the predicted image feature value data string d _{cycle_next} (m) is equal to or smaller than the threshold Th _next , the phase pattern generation unit 203a deletes the grids before and after the m-th grid from the grid series. At that time, the phase pattern generation unit 203a makes the respective lattice widths of the new lattice rows obtained by deleting the lattices from the lattice rows become equal intervals. The phase pattern generation unit 203 leaves the number of the edge of the lattice row S4, for example, m, which is the center number from m−1, m, and m + 1.

As described above, according to the first embodiment and the second embodiment of the present invention, the three-dimensional shape measurement apparatus 20 adapts the three-dimensional shape of the moving object MO to be measured and projects the phase pattern data to be projected. Since the lattice pattern is dynamically changed, the three-dimensional shape can be measured with high accuracy even at a location where the rate of change in the depth of the moving object MO is large.
Further, according to the first and second embodiments of the present invention, the three-dimensional shape measuring apparatus 20 uses the image feature amount data from the phase image data of the moving object MO imaged while the imaging apparatus 30 shifted the phase. Therefore, the phase pattern data to be projected can be generated and the phase pattern data can be generated at high speed. Therefore, it is easy to configure the three-dimensional shape measuring apparatus 20 using an information processing apparatus such as a general-purpose computer.

Note that the projection and imaging of the phase pattern data may be performed with a light beam having a wavelength (for example, infrared light) outside the visible light wavelength region. In this case, a filter having the same optical characteristics is provided in the optical system of the projection device 10 and the optical system of the imaging device 30.
In addition, the image feature extraction unit 201 in the first embodiment and the second embodiment may be provided on the imaging device 30 side. With this configuration, there is no need to transfer the phase image data itself.

  In addition, you may make it implement | achieve the function of a part of three-dimensional shape measuring apparatus which is embodiment mentioned above, for example, a control part with a computer. In this case, a three-dimensional shape measurement program for realizing the control function is recorded on a computer-readable recording medium, and the three-dimensional shape measurement program recorded on the recording medium is read by the computer system and executed. It may be realized by. Here, the “computer system” includes an OS (Operating System) and hardware of peripheral devices. The “computer-readable recording medium” refers to a portable recording medium such as a flexible disk, a magneto-optical disk, an optical disk, and a memory card, and a storage device such as a hard disk built in the computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case may be included and a program that holds a program for a certain period of time may be included. Further, the above program may be for realizing a part of the functions described above, or may be realized by a combination with the program already recorded in the computer system. .

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design etc. of the range which does not deviate from the summary of this invention are included.

DESCRIPTION OF SYMBOLS 1 Three-dimensional shape measurement system 10 Projection apparatus 20, 20a Three-dimensional shape measurement apparatus 21 Image | video input I / F part 22 Control part 23 Memory | storage part 24 Image | video output I / F part 25 Display I / F part 30 Imaging device 40 Display apparatus 201 Image feature amount extraction unit 202 Image feature amount storage unit 203, 203a Phase pattern generation unit 204 Image feature amount comparison unit 205 Image feature amount sequence storage unit 211 Phase image storage unit 212 Phase distribution image generation unit 213 Phase connection unit 214 Three-dimensional shape Generation unit 215 Three-dimensional shape storage unit BS Back screen MO Moving object

Claims (6)

A phase image data acquisition unit for acquiring phase image data obtained by imaging the measurement target object on which the phase pattern is projected and the reflection pattern from the back screen by shifting the phase in time series;
An image feature amount extraction unit that detects an edge corresponding to the phase pattern from the acquired phase image data and extracts image feature amount data according to the strength of the edge;
A phase pattern generation unit that generates phase pattern data in which a lattice width is adjusted based on an image feature amount data sequence for one phase extracted by the image feature amount extraction unit;
A phase distribution image generation unit that generates phase distribution image data based on a phase image data sequence for one phase acquired by the phase image data acquisition unit;
A phase connection unit for generating continuous phase distribution image data by performing phase connection of the generated phase distribution image data;
Based on the generated continuous phase distribution image data, a three-dimensional shape generation unit that generates three-dimensional shape data of the measurement object according to a triangulation method,
A three-dimensional shape measuring apparatus comprising: The three-dimensional shape measuring apparatus according to claim 1,
Based on the image feature quantity data sequence for one phase extracted by the image feature quantity extraction unit and the image feature quantity data sequence one phase earlier than this image feature quantity data sequence, predicted image feature quantity data An image feature amount comparison unit for generating a sequence;
The three-dimensional shape measuring apparatus, wherein the phase pattern generation unit generates phase pattern data in which a lattice width is adjusted based on a predicted image feature amount data sequence generated by the image feature amount comparison unit. A phase image data acquisition step for acquiring phase image data obtained by imaging the measurement target object on which the phase pattern is projected and the reflection pattern from the back screen by shifting the phase in time series; and
An image feature amount extraction step of detecting an edge corresponding to the phase pattern from the acquired phase image data and extracting image feature amount data corresponding to the strength of the edge;
A phase pattern generation step of generating phase pattern data in which the lattice width is adjusted based on the image feature amount data sequence for one phase extracted in the image feature amount extraction step;
While having
A phase distribution image generation step of generating phase distribution image data based on a phase image data sequence for one phase acquired in the phase image data acquisition step;
A phase connection step of performing phase connection of the generated phase distribution image data to generate continuous phase distribution image data;
Based on the generated continuous phase distribution image data, a three-dimensional shape generation step for generating three-dimensional shape data of the measurement object according to a triangulation method,
A three-dimensional shape measuring method characterized by comprising: In the three-dimensional shape measuring method according to claim 3,
Based on the image feature quantity data sequence for one phase extracted in the image feature quantity extraction step and the image feature quantity data sequence one phase earlier than the image feature quantity data sequence, predicted image feature quantity data An image feature amount comparison step for generating a sequence;
The phase pattern generation step generates phase pattern data in which a lattice width is adjusted based on the predicted image feature amount data sequence generated in the image feature amount comparison step. Computer
A phase image data acquisition unit for acquiring phase image data obtained by imaging the measurement target object on which the phase pattern is projected and the reflection pattern from the back screen by shifting the phase in time series;
An image feature amount extraction unit that detects an edge corresponding to the phase pattern from the acquired phase image data and extracts image feature amount data according to the strength of the edge;
A phase pattern generation unit that generates phase pattern data in which a lattice width is adjusted based on an image feature amount data sequence for one phase extracted by the image feature amount extraction unit;
A phase distribution image generation unit that generates phase distribution image data based on a phase image data sequence for one phase acquired by the phase image data acquisition unit;
A phase connection unit for generating continuous phase distribution image data by performing phase connection of the generated phase distribution image data;
Based on the generated continuous phase distribution image data, a three-dimensional shape generation unit that generates three-dimensional shape data of the measurement object according to a triangulation method,
3D shape measurement program to make it function. Computer
A phase image data acquisition unit for acquiring phase image data obtained by imaging the measurement target object on which the phase pattern is projected and the reflection pattern from the back screen by shifting the phase in time series;
An image feature amount extraction unit that detects an edge corresponding to the phase pattern from the acquired phase image data and extracts image feature amount data according to the strength of the edge;
A phase pattern generation unit that generates phase pattern data in which a lattice width is adjusted based on an image feature amount data sequence for one phase extracted by the image feature amount extraction unit;
A phase distribution image generation unit that generates phase distribution image data based on a phase image data sequence for one phase acquired by the phase image data acquisition unit;
A phase connection unit for generating continuous phase distribution image data by performing phase connection of the generated phase distribution image data;
Based on the generated continuous phase distribution image data, a three-dimensional shape generation unit that generates three-dimensional shape data of the measurement object according to a triangulation method,
A computer-readable recording medium on which a three-dimensional shape measurement program for functioning is recorded.

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