JPS6154577A - Labeling device for contour feature point - Google Patents

Abstract

PURPOSE:To decide feature points regardless of the position of a subject form by deciding a base point based on an amount that has no relation with the position of the subject form in a screen and using this base point as a start point to put numbers successively on the feature points in the prescribed direction along a contour. CONSTITUTION:Both corner points P1-P4 and bottom points N1-N8 are detected as the feature points of the contour of a subject form F. These bottom points are connected successively for approximation to a polygon. The maximum side length has no relation with the change of position of the form F due to shift, rotation, etc. Therefore the length of each side is checked and an end of the longest side is defined as a base point in the fixed direction (clockwise), and the numbers are put successively in a prescribed direction A. In case plural longest sides exist (a, c), the adjacent sides (b) and (d) are compared with each other. Then the longer side (d) replaced with the longest side to decide the base point. As a result, the point N1 is defined as a base point and thereafter the numbers are put to N2-N8 successively. For the corner points, the point P1 having the longest distance from the centroid is defined as a base point. Then the numbers are put to points P2-P4 respectively.

Description

[Detailed Description of the Invention] [Technical Field to which the Invention Pertains] The present invention relates to, for example, an assembly robot, an automatic semiconductor bonding device, etc., which uses a two-dimensional imaging means to detect parts (objects) to be manipulated or processed. It is related to a device that captures an image of an object such as a component, uses it as feature points in its contour, and detects handling points, bonding points, etc.

[Prior art and its problems]

In the following description of each figure, the same reference numerals indicate the same or corresponding parts.

Conventionally, a technique for capturing an image of an object to be imaged as the target part and detecting a limbal feature point of the image, which becomes a target point for manipulation or processing in the part, was disclosed in a patent application filed by the present applicant, Koyo Flea. No. 58-76771 "Contour feature detection method" (hereinafter referred to as document (1)).

FIG. 3 shows an example of feature points determined by this method. That is, in the figure t, F is the target part 20.

A binarized image showing the two-dimensional shape of , P is this binarized image F
Protrusions as feature points on the contour (hereinafter referred to as corner points), N
is also a depression (hereinafter referred to as a valley point) as a feature point. Note that G indicates the center of gravity (centroid) of the image F, and X and Y indicate the axes of image scanning.

In this way, in the above method, the types of feature points, such as corner points P and valley points N, and their positions on the X and Y axes. Although the number has already been detected, the movement of the center of gravity G of the target part 200 and thus the binarized image F and the rotation around the center of gravity G (hereinafter, the displacement of such a part 200 or image F is simply expressed as 5 arrangement 1 or 1 (referred to as movement or rotation 1)
, even if the detection order of feature points changes, specific feature points on the contour can be identified. Not yet. Therefore, in this prior art, the target parts 200 that are mounted on the workbench sound device in various locations are
There is a problem in that the above specific operation or the position of the point to be processed cannot be detected.

[Purpose of the invention]

An object of the present invention is to eliminate the above-mentioned problems and to provide a contour feature point that can specify the specific operation or processing target point, and therefore the position of a predetermined feature point on the contour of the image, regardless of the arrangement of the target part. The purpose is to provide a numbering (also called labeling) device.

[The point of invention]

The gist of this invention is to clearly track the contour of the target shape in a two-dimensional image of the target part in a fixed direction fζ all around, detect shape feature points in the contour part using the contour information obtained at this time, and Approximate the target shape to a polygon using the feature points, use one of the feature points as a base point, trace the circumference of the polygon in a predetermined direction, and compare each feature point t that appears. There are points for sequential numbering.

In addition, for the base point, for example, one end of the side with the maximum side length among the sides of the polygon may be used, or the distance between the center of gravity of the target shape and each feature point. Maximum flQ
In other words, the main point of the present invention is to use certain points. The outline pixels of the target binarized image (obtained by digitizing) are
The binarized image is sequentially tracked in a predetermined direction (for example, counterclockwise, hereinafter referred to as the contour tracking direction) (via a contour tracking circuit, etc.), and each image obtained at this time is Based on the coordinate value of the contour pixel and the tracking direction code indicating the tracking direction to the adjacent contour pixel, (via a feature detection circuit, etc.) a predetermined feature such as a protrusion or indentation on the contour is determined to represent a predetermined feature /I3. A device that detects the positions of contour pixels (hereinafter referred to as feature points) (such as corner points or valley points) in the order of going around the contour once in a predetermined direction (for example, counterclockwise) and stores them in the 111μ order. At tC, the feature points are divided into a first group consisting of all Cs (e.g. # including all Cs of corner points and valley points) or a second group of +12 numbers (e.g. consists of only corner points or only valley points?) When dividing, each feature point in the same group is divided so that each of the first or second groups goes around the contour once. A side length calculation means for calculating each side length of a polygon obtained by sequentially connecting the polygons, or (and) a center of gravity of the binarized image obtained through a center of gravity calculation circuit, etc., and each feature in the same group. Distance to point tm:
(hereinafter referred to as the center of gravity distance) [calculating means; base point determining means for determining a base point (referred to as a base point).

feature point labeling means for sequentially assigning numbering to each feature point in the group so as to go around the contour once in a predetermined direction (for example, counterclockwise); If the base point determining means is set at a predetermined side (for example, a clockwise side) with respect to the contour tracing direction on both sides of the side having the maximum value among the six side lengths, ) including means for making the feature point located in ) the base point,
Alternatively, the base point determining means may include means for setting the feature point corresponding to the maximum of the respective center of gravity distances as the base point. When there are multiple base points belonging to the same group + C, each base point of the koji number is on the predetermined side (for example, clockwise all), and each side E of the maximum side length is set in the contour tracing direction; A predetermined side (for example, the counterclockwise side) to be referred to as a standard, and means for comparing the side lengths of the adjacent polygons are provided, and on both sides of the side having the maximum value among the adjacent side lengths, A point including a means for determining a feature point located on a predetermined side (for example clockwise 1!+) with respect to the contour tracing direction as a new base point, or a feature point located on a predetermined side (for example clockwise 1!+) with respect to the contour tracing direction, When there are multiple base points to which the multiple base points belong, the side of the polygon that makes each of the multiple base points a predetermined side (for example, clockwise side) with respect to the contour tracking circuit is opposite to the center of gravity l, The kiln number includes a means for comparing the angles (side facing angles, etc.) between the two angles, and a means for determining the base point corresponding to the largest of the angles as a new base point.

[Embodiments of the invention]

The present invention will be described in detail below with reference to FIGS. 1 and 2.

Fig. 1 is a block diagram showing the configuration of an embodiment of the present invention, and Fig. 2 is an example of feature points on the contour of a binary image of a detected and numbered target part based on Fig. 1. FIG.

In FIG. 1, 200 is a target part, and 201 is a two-dimensional imaging device that images this two-dimensionally, scans the image in the X and Y axis directions, and converts it into image No. 18. 202 is an A/D converter, and the surface IC of the target part 200
The level at which an appropriate S/N ratio can be obtained for the analog video signal output from the two-dimensional imaging device ff1201, which changes depending on the brightness and hue of the target component 200I
The area of the target part 200 is digitized (z-valued) at the corresponding level, the background and the area of the target part 200 are separated, and a binarized image F of the target part is created.
This is a circuit that obtains the following. 203 is a contour tracking circuit that moves contour pixels (also referred to as contour points) of the target shape in a certain direction (for example This is a circuit that performs counterclockwise tracking (1) and obtains the coordinate value of each contour point and the direction code to the next adjacent contour point. The details of this circuit are described in Japanese Patent Application No. 58-9108 entitled "Pattern Contour Tracing Method" by the present applicant, Koyoru Mori. 204 is a feature detection circuit which detects feature points (corner points P,
This is a circuit that detects the positions of valley points (N, etc.) and stores them in the order of detection. An example of this circuit is explained in detail in the above-mentioned document (1). Reference numeral 205 denotes a feature point numbering circuit, which assigns a fixed numbering to each feature point detected by the feature detection circuit 204 so as to be unrelated to the movement or rotation of the image F on the screen. This is the core of the invention. 20
Reference numeral 6 denotes a centroid calculation circuit which calculates the centroid of the object shape in order to reinforce the function of the feature point numbering circuit 205.

Next, using FIG. 2, the operation of numbering for each feature point call by the component device shown in FIG. 1 will be explained. In FIG. 2, the corner point P as a detected feature point is represented by Pi-P4, and the valley point N is similarly represented by N1-N3.

Note that in this example, corner points P, (P 1 to P4) and valley points N (N
1 to N8), numbering is performed using separate means within the feature point numbering circuit 205.

First, the numerical nature of the valley point N will be explained in detail. Target shape (
Valley points N1~ detected from the outer contour of the binarized image F)
Connect N8 in the tracing direction of contour points (counterclockwise) in order of A to perform polygonal approximation, and at the same time check the length of each side of this polygon, find the maximum side length, and use this maximum side length. With one end of the side in a predetermined direction (this direction is determined based on the tracking direction A, here, for example, clockwise) as a base point,
A predetermined direction (for example, counterclockwise direction A) + missing numbering is performed in this order.

However, in the example shown in Figure 2, the longest side a and the second longest side C are almost equal in length and cannot be distinguished from each other with a significant difference, so in such a case, for example, the following rule apply. That is, side a.

Compare the side lengths of adjacent sides d and Cl in a predetermined direction (for example, counterclockwise A), replace the longer side (d in this case) with the maximum side length tC, and The purpose is to determine the base point N1 and perform the sequential numbering of each of the points N2 to N8 following this point.Thus, by performing the numbering of each feature point, the movement of the images in the screen and Unambiguous t-numberality can be performed regardless of rotation.

Next) For this corner point P + bump, numbering may be done in the same way as for the valley point N, or by connecting all the feature points of the valley point N and corner point P in the order of appearance in the tracking direction A. , troughs, and corner points, and calculate the base point of this new polygon by the same method as described above. If this base point is a trough point, then Nl.

The corner point is defined as PI, and from now on, while tracing each side of the new polygon in a counterclockwise direction (tracing direction A), numbering is performed in order for each type of valley point and corner point. Good too.

However, regarding the corner point P+ in FIG. 2, an example of performing numbering in a different manner is shown below. In other words, among the distances (also called center of gravity ^] L) between the center of gravity G of both images F and each corner point P (P1 to F4), the maximum distance is found and used as the base point, and the following is the same as above (counterclockwise) Direction A
) to perform sequential numbering. However, in the case of Fig. 2, the center of gravity distance e
(Corresponding to corner point P41c).

Since and f (corresponding to the corner point Fir) are approximately equal and the maximum distance is +, the base point is determined by applying the following rules.

That is, the sides P4.PI, Pi, P2 connecting the corner points P4.PI and P4.PL located at the maximum pressure 1ζ (in the tracking direction A+) and the adjacent corner points Pi, P2 are the center of gravity G+ The angle (also called side-opposite angle) made by this and.

The angles β are compared, and the angle point corresponding to the larger angle β is set as Pl, and the numbering of the angle points P2 to P4 is performed in the same manner as described above.

〔Effect of the invention〕

As is clear from the above description, according to this invention,
On the contour of the target shape - The base point of each detected feature point is defined as the side length of a polygon connecting each Qi feature point along the contour, or the distance between each feature point and the center of gravity of the target shape. It is determined based on a quantity, such as a distance, that is unrelated to the arrangement of the target shape in the screen, and other feature points are sequentially numbered in a predetermined direction t along the contour using the base point as a starting point. Therefore, the numbers of all feature points can be determined regardless of the movement or rotation of the target shape, and therefore, even when the feature points are used as target points for manipulation or processing, they are independent of the arrangement of the target parts. It becomes possible to perform necessary operations and processing on parts.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG.
The figure shows an example of a binarized image of the target part to explain the operation of Fig. 1, and Fig. 3 shows an example of feature points on the contour of the binarized image detected based on the conventional technique. It is a diagram. 200... Target part, 201... Two-dimensional imaging device, 202... A/D converter, 203
... Contour tracking circuit, 204 ... Feature detection circuit, 205 ... Feature point numbering circuit, 206
... Center of gravity calculation circuit, P (P1 to P4) ...
・Corner point, N (N1~N!3)・・・Trough point, G・
...center of gravity, a, a...side, e-g...
... Center of gravity distance, α, β ... Side opposite angle. ↓ Fig. 2 ψ O Fig. 3

Claims (1)

[Claims] 1) The contour pixels of the target binarized image are sequentially traced around the binarized image in a predetermined direction (hereinafter referred to as the contour tracking direction), and each of the contour pixels obtained at this time is The coordinate value of the contour pixel,
The position of a contour pixel (hereinafter referred to as a feature point) representing a predetermined characteristic portion such as a protrusion or depression on the contour is determined from the tracking direction code indicating the tracking direction to the adjacent contour pixel, and the contour is moved in a predetermined direction. In a device that detects feature points in the order of one round and stores them in that order, when classifying the feature points into a first group consisting of all of the feature points or a plurality of second groups grouped by characteristics that they share, Side length calculation means for calculating each side length of a polygon obtained by sequentially connecting each feature point in the same group so as to go around the contour once for each first or second group, or ( and) a centroid distance calculation means for calculating the distance between the centroid of the binarized image and each feature point in the same group (hereinafter referred to as centroid distance); ) base point determining means for determining a point (hereinafter referred to as a base point) representative of the feature points in the group based on each center-of-gravity distance; 1. A contour feature point labeling device comprising: feature point labeling means for sequentially numbering each feature point in the group so as to make one round. 2) In the apparatus according to claim 1, the base point determining means determines, as the base point, a feature point located on a predetermined side with respect to the contour tracing direction on both sides of the side having the maximum value among the respective side lengths. 1. A contour feature point labeling device comprising means for labeling contour feature points. 3) In the apparatus according to claim 1 or 2, the base point determining means includes means for setting a feature point corresponding to the largest one among the respective center-of-gravity distances as the base point. Labeling device for contour feature points. 4) In the apparatus according to claim 2 or 3, when a plurality of base points belong to the same group, the base point determining means selects each of the plurality of base points to the predetermined side. For each side of the maximum side length, a means for comparing the side lengths of the adjacent polygons is provided on a predetermined side with respect to the contour tracing direction, and the polygon has the maximum value among the adjacent side lengths. A labeling device for contour feature points, comprising means for determining a feature point located on a predetermined side with respect to the contour tracing direction as a new base point on both sides of the edge. 5) In the apparatus according to claim 3 or 4, when a plurality of base points belong to the same group, the base point determining means selects each of the plurality of base points in the contour tracking direction. means for comparing angles that sides of the polygon make with respect to the center of gravity, and means for determining a base point corresponding to the largest of the angles as a new base point. A contour feature point labeling device characterized by the following.