JPH02114110A - Method for detecting three-dimensional object - Google Patents

Abstract

PURPOSE:To detect a complicated three-dimensional object by avoiding that image processing becomes complicated by displaying the image corresponding to a slit light image by a segment composed of continuous white pixels and calculating a reference line from the intermediate point of the segment. CONSTITUTION:A three-dimensional object M is irradiated with slit light SL and the image of the three-dimensional object M irradiated with the slit light SL is read in an image processor 14. The read image of the three-dimensional object M is processed to search the continuous white pixels corresponding to a slit light image SP to detect a segment and the intermediate point of the detected segment is calculated. The reference line corresponding to the slit light image SP on the plane on which the three-dimensional object M is placed is calculated from the detected segment. Then, the distance between the calculated intermediate point of the reference line is calculated.

Description

[Detailed Description of the Invention] fl) Purpose of the Invention [Industrial Application Field] The present invention relates to a method for detecting a three-dimensional object, and in particular, the present invention relates to a method for detecting a three-dimensional object, in particular a three-dimensional object detected by reading a three-dimensional object illuminated with slit light using a video camera. Search for continuous white pixels corresponding to the slit light image from the image of the object, find a line segment from the continuous white pixels, calculate the center point of the line segment, and calculate the plane on which the three-dimensional object rests from the center point of the line segment. Detect the reference line corresponding to the upper slit light image,
The present invention relates to a three-dimensional object detection method that calculates the distance between a reference line and the center point of each line segment, and detects a three-dimensional object based on the calculated distance.

[Prior Art] Conventionally, this type of three-dimensional object detection method detects a three-dimensional object by irradiating a three-dimensional object with slit light in a certain direction so as to intersect with each other by a first slit light irradiation device and a second slit light irradiation device. is read by a video camera, and an image corresponding to the slit light image is extracted by removing from the image of the three-dimensional object the image corresponding only to the three-dimensional object read in advance by the video camera, and an image corresponding to the slit light image is extracted. Among the pixels included in the image, the pixels that are adjacent to each other are the I coordinate of the fifth pixel at the monitor screen coordinates (1, J) on which the image is displayed. Three definition formulas regarding fJl and an appropriate threshold TH. It has been proposed to detect the shape of a three-dimensional object by displaying a slit light image by expressing it as
．． June 1986).

[Problems to be solved] In conventional three-dimensional object detection methods, (i) each pixel corresponding to a slit light image is expressed individually using a definition formula, so when a three-dimensional object has a complex shape, image processing becomes difficult. This method has the disadvantage of being synergistically complicated, and since the slit light is irradiated in a fixed direction, it is practically impossible to detect a three-dimensional object with a complicated shape.

Therefore, in order to eliminate these drawbacks, the present invention displays an image corresponding to a slit light image as a line segment made up of continuous white pixels, finds the midpoint of the line segment, and further calculates a reference line from the midpoint. , it is an object of the present invention to provide a three-dimensional object detection method that detects a three-dimensional object by calculating the distance between a reference line and each intermediate point.

(2) Structure of the invention [Means for solving the problems J The means for solving the problems provided by the present invention are [(a)
a slit light irradiation step of irradiating a three-dimensional object with slit light; (b) an image reading step of reading an image of the three-dimensional object irradiated with the slit light; a line segment detection step in which a line segment is detected by processing an image of the object and searching for continuous white pixels corresponding to the slit light image; and fd) an intermediate step in which the midpoint of the line segment detected in the line segment detection step is calculated. (e) a reference line calculation step for calculating a reference line corresponding to the slit light image on the plane on which the three-dimensional object rests from the line segment detected in the line segment detection step; (f) intermediate point calculation A three-dimensional object detection method comprising: a distance calculation step of calculating a distance between an intermediate point calculated in the step and a reference line calculated in the reference line calculation step.

A line segment detection process that processes the image of the three-dimensional object read in the reading process and searches for continuous white pixels corresponding to the slit light image to detect line segments, and a line segment detected in the fdl line segment detection process. a midpoint calculation step of calculating the midpoint of [e
l) A reference line calculation step that calculates a reference line corresponding to the slit light image on the plane on which the three-dimensional object rests from the line segment detected in the line segment detection step; Since it includes a distance calculation step of calculating the distance between the reference line calculated in the reference line calculation step, it is possible to suppress the image processing from becoming complicated even if the shape of the (il=dimensional object becomes complex). Furthermore, (ii) it has the effect of ensuring the detection of complex three-dimensional objects.

[Operation 1] The three-dimensional object detection method according to the present invention includes (1) (a) a slit light irradiation step of irradiating a three-dimensional object with slit light; and (c1 image [Example]) Next, the three-dimensional object detection method according to the present invention will be specifically explained by citing an example. This is described to facilitate or promote understanding of the present invention, and is not described to limit the present invention.In other words, each member disclosed in the Examples described below It is intended to include all design changes and equivalent substitutions that come within the spirit and technical scope of the invention.

FIG. 3 is a flowchart showing an embodiment of the three-dimensional object detection method according to the present invention, which is executed in FIG.

FIG. 5 is a flowchart that further embodies the flowchart shown in FIG. 4.

FIG. 6 is an explanatory diagram for conceptually explaining the work in the flowchart shown in FIG.

FIG. 1 is a perspective view showing a three-dimensional object detection apparatus for carrying out an embodiment of the three-dimensional object detection method according to the present invention.

FIG. 2 is an explanatory diagram for explaining the operation of the three-dimensional object detection device shown in FIG. 1, and shows the contents of the image signal Sv given from the video camera 12 to the image processing device 14.

FIG. 3 is an explanatory diagram for explaining the operation of the three-dimensional object detection device shown in FIG. 1, and shows the contents of the slit light image S V3L extracted from the image signal Sv.

Figure 4 shows the three-dimensional object detection device shown in Figure 1.
The configuration of a three-dimensional object detection apparatus for carrying out an embodiment of the three-dimensional object detection method according to the present invention will be described with reference to the drawings.

A three-dimensional object detection device for carrying out the three-dimensional object detection method according to the present invention includes a slit light generating device 1) for generating the slit light SL and a slit light generating device 1). a video camera 12 for reading the three-dimensional object M irradiated with the slit light SL;
The slit light generator 1) and the video camera 12 are respectively connected to an image processing device 14 via connection cables 13A and 13B, and a monitor device 16 is connected to the image processing device 14 via a connection cable 15. .

Furthermore, with reference to FIGS. 1 to 6, an embodiment of the three-dimensional object detection method according to the present invention will be described while explaining the operation of the three-dimensional object detection apparatus shown in FIG. The action will be explained in detail.

In this state, an image of the three-dimensional object M is read by the video camera 12. The image of the three-dimensional object M read by the video camera 12 is sent to the image processing device 14 via the direct reading cable 13B as an image signal Sv as shown in FIG.
is given to the slit light image S in the image processing device 14.
The 0 image signal Sv and the slit optical image signal S VffL from which only P is taken out and the slit optical image signal S VIL as shown in FIG. be done.

In the three-dimensional object detection device 10, the slit light generation signal SQL generated by an appropriate circuit built in the image processing device 14 is given to the snow light generation device 1) via the connection cable 13A, so that the slit light generation signal SQL is generated as appropriate. The slit light SL is generated. The slit light SL generated by the slit light generator 1) is irradiated onto a three-dimensional object M placed within the detection area, and for example, a slit light image SP as shown in FIG. Formed on object M.

In the image processing device 14, the slit optical image signal S extracted from the image signal Sv given from the video camera 12
As shown in FIG. 4, VIIL is processed in the following manner to detect the three-dimensional object M.

That is, the image processing device 14 processes the slit optical image signal S
A continuous white pixel corresponding to the slit light image SP is searched for in VIL (step l). When a continuous white pixel is searched, a line segment ˜L4 on which the continuous white pixel lies is detected (step 2). It is determined whether line segment detection has been completed for the entire slit optical image signal S VIIL (step 3), and the continuous white pixel search operation and The line segment detection operation is repeated (steps 1-3).

When the line segment detection operation is completed for the entire slit light image SVIIL, the intermediate points P1 to P4 of each line segment ~L4
(Step 4). When the intermediate points P and -P4 of each line segment L1 to L4 are calculated.

A straight line (also referred to as "base line °") I2 corresponding to the slit light image SP on the background, that is, the plane on which the three-dimensional object M rests, is calculated (step 5). When the base line 2 is calculated, The distance from the intermediate point P, -P of each line segment ~L4 to the reference !jAI2, -h.

is calculated (step 6), and the shape of the three-dimensional object M is recognized based on the distance, ~h4 (step 7).

The continuous white pixel search operation and line segment detection operation described above (
Steps 1 and 2) are achieved, for example, by the series of operations shown in FIG. 5 in the following manner.

That is, first, the starting point (X,) of continuous white pixels.

y1) (step 1-1). After the starting point (X*-yj) of continuous white pixels is searched, the ending point (x a
, :J j is searched (step 1-2).

After that, the starting point of continuous white pixels (x s, :J,)
The length of the line segment L (for example, L1 to L1) passing through and the terminal point (X e, : J el
e) 2)"2 and the starting point (xm, ysl to the ending point (x
Calculate the difference Δt=lK−N1 from the tracking trajectory length N when tracking up to ay @1 (step 2-1). Once the difference Δt is calculated, check whether the difference Δt is almost 0 or not. (Step 2-2).

If the difference Δt is not approximately 0, set the equation of the line segment corresponding to continuous white pixels as y=ax+b (step 2-3)
, from the line segment, the length h of a perpendicular drawn to each traced point (ie, traced point) Q is determined as shown in FIG. 6 (step 2-4). Let the tracking point Q where the length h of the perpendicular line is maximum be the terminal point (x s, y el (step 2-
5), then calculate the difference Δt again (step 2-1
).

On the other hand, when the difference Δt becomes approximately O, it is determined whether the line segment detection operation has been completed (step 3).

(3) Effects of the Invention As is clear from the above, the three-dimensional object detection device according to the present invention includes (a) a slit light irradiation step of irradiating a three-dimensional object with a slit light; (b) a slit light ! an image reading step of reading an image of a three-dimensional object that has been irradiated with 1G; A line segment detection process that detects the line segment, (a midpoint calculation process that calculates the midpoint of the line segment detected in the dl line segment detection process, and a midpoint calculation process that calculates the midpoint of the line segment detected in the (el ljA segment detection process), a reference line calculation step that calculates a reference line corresponding to the slit light image on the plane; g) the distance between the intermediate point calculated in the intermediate point calculation step and the reference line calculated in the reference line calculation step; This method has the effect of suppressing the complexity of image processing even when the shape of a three-dimensional object becomes complex, and furthermore, (1)) It has the effect of ensuring detection.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a three-dimensional object detection device for carrying out an embodiment of the three-dimensional object detection method according to the present invention, and FIG. 2 shows the operation of the three-dimensional object detection device shown in FIG. FIG. 3 is an explanatory diagram for explaining the operation of the three-dimensional object detection device shown in FIG. 1, and FIG.
A flowchart showing an embodiment of the three-dimensional object detection method according to the present invention executed by the three-dimensional object detection apparatus shown in the figure, FIG. 5 is a more specific version of a part of the flowchart shown in FIG. The flowchart shown in FIG. 6 is an explanatory diagram for conceptually explaining the operations in the flowchart shown in FIG. 16... M... SL... SP... S! IL...SV...SV! IL・・・・Monitoring device・・・Three-dimensional object・・・・・・Slit light・・・・・・Slit light image・・・・・・Slit light generation signal・・・・・・Image signal...Slit light image signal

Claims (2)

[Claims] (1) (a) A slit light irradiation step in which a three-dimensional object is irradiated with slit light; (b) An image reading step in which an image of the three-dimensional object irradiated with the slit light is read; (c) Image reading a line segment detection step in which the image of the three-dimensional object read in the process is processed to search for continuous white pixels corresponding to the slit light image to detect line segments; and (d) the line detected in the line segment detection step. (e) a reference line calculation step of calculating a reference line corresponding to the slit light image on the plane on which the three-dimensional object rests from the line detected in the line segment detection step; and (f) a distance calculation step of calculating the distance between the intermediate point calculated in the intermediate point calculation step and the reference line calculated in the reference line calculation step. (2) The line segment detection step includes (c_1) a first step of searching for the starting point (x_s, y_s) of continuous white pixels, and (c_2) a first step of searching for the ending point (x_e, y_e) of continuous white pixels. (c_3) Length L of the line segment from the start point (x_s, y_s) to the end point (x_e, y_e) of continuous white pixels = {(
x_s-x_e)^2+(y_s-y_e)^2}^1
A third step that calculates the difference Δt=|L−N| between ^/^2 and the tracking trajectory length N when tracing continuous white pixels from the starting point (x_s, y_s) to the ending point (x_e, y_e). and (c_4) a fourth step that determines whether the difference Δt is approximately 0 or not.
(c_5) When it is determined in the fourth step that the difference Δt is not approximately 0, the starting point (x_s, y_s) and the ending point (x_e, y
(c_5) A fifth step of calculating a line segment passing through (c_5) from each point when tracing the continuous white pixels from the starting point (x_s, y_s) to the ending point (x_e, y_e). (c_7) The point where the length of the perpendicular is the maximum is the terminal point (x_e
, y_e), and when it is determined that the difference Δt is approximately 0, the process moves to an intermediate point calculation step. The three-dimensional object detection method described in (1).