JPH04178783A - Pattern position recognizing method - Google Patents

Abstract

PURPOSE:To recognize a pattern position with a high precision at a high speed by finding a pattern, which synthetically coincides a standard pattern most, from partial patterns of a two-dimensional pattern of an inputted position recognition object to recognize a specific position of the two-dimensional pattern of the inputted position recognition object. CONSTITUTION:A pattern 4 coinciding with a standard pattern 7 of designated picture elements most is searched in partial patterns of the two-dimensional pattern including an image 3 of the inputted object, and a specific position 5 in the object of this pattern 4 is recognized. In this case, gradation values of designated picture elements stored in the standard pattern 7 and those of corresponding picture elements in partial patterns are taken as the comparison object. Therefore, the pattern 4 is found at a high speed. Thus, a merit of position recognition of high precision using gradation patterns or the like is kept and the processing speed is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a pattern position recognition method using an image input device such as a television camera and a computer.

BACKGROUND OF THE INVENTION In recent years, measuring instruments used for pattern position recognition are increasingly required to be highly accurate and fast.

The following is a third example of the conventional pattern position recognition method.
This will be explained with reference to FIGS.

FIG. 3 shows a two-dimensional pattern including an image 1 of the object, and 2 is a standard pattern set in a specific part of the image 1.

The fourth issue is an enlarged view of this standard pattern 2. FIG. 5 is an input pattern including an image 3 of the object whose position is to be recognized,
4 is a matching pattern that most closely matches standard pattern 2, and 5 is a specific position of matching pattern 4.

In the conventional pattern position recognition method, first, a two-dimensional pattern of a specific part of the target image 1 is stored in advance as a standard pattern 2. At this time, it is stored as a binary pattern or a gray pattern. Note that this standard pattern 2 may be any pattern as long as it can be distinguished from other parts. Then, the image 3 of the target in the input cover pattern is
matching pattern 4 that best matches standard pattern 2 from
is searched for, and the position of the target image 3 is specified at a specific position 5 within this matching pattern 4. Note that in FIG. 5, the specific position 5 is the upper left corner of the standard pattern 2;
Any position may be used as long as the spatial positional relationship is clear (such as the lower right corner or the center of the standard pattern 2). The position of the object is recognized in the above manner.

Problems to be Solved by the Invention However, such conventional methods have a problem in processing speed, especially when using a gray pattern, and there is a problem in that high-speed position recognition is not possible.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of recognizing a pattern position with high precision and at high speed using a grayscale pattern or the like.

Means for Solving the Problems In order to solve the above-mentioned problems, the pattern position recognition method of the present invention is based on a pattern position recognition method in which a pattern consisting of only specified pixels having valid information in a two-dimensional pattern of a specific part of an object is preliminarily set as a standard pattern. Recognizes a specific position in the input two-dimensional pattern of the position recognition target by memorizing it and finding the matching pattern that best matches the standard pattern from the partial patterns of the input two-dimensional pattern of the input position recognition target. It is characterized by

Effects According to the present invention, pattern position recognition is performed using a standard pattern consisting only of specified pixels having valid information.
A specific position can be recognized with high precision and high speed.

EXAMPLE Hereinafter, a pattern position recognition method according to an example of the present invention will be explained with reference to FIGS. 1, 2, and the above-mentioned FIGS. 3 to 5. In this embodiment, a partial pattern 6 as shown in FIG. 2 is selected as a partial pattern to create a standard pattern consisting only of specified pixels with valid information, and edge detection processing is performed on this partial pattern 6. A standard pattern 7 of designated pixels as shown in FIG. 1 in which only the gray scale values of pixels around edges are stored is used. Note that the standard pattern 7 has a size of 12×12 and a gradation of 64 shades.

To explain the process of setting the standard pattern 7 for specified pixels, select a partial pattern 6 in a specific part corresponding to the standard pattern 2 in the target image 1 in FIG. filter,
A pixel whose absolute value of the processing result of each pixel exceeds a certain threshold value is regarded as an edge and is designated as a designated pixel. A pattern in which the gradation values of only such designated pixels are stored is defined as a standard pattern 7 for designated pixels.

Then, as shown in FIG. 5, a match pattern 4 that most closely matches the standard pattern 7 of the designated pixels is searched for the partial pattern of the two-dimensional pattern including the input image 3 of the target, and the target of the match pattern 4 is searched for. Recognize a specific position 5 within. At this time, since only the gray value of the specified pixel stored in the standard pattern 7 and the gray value of the corresponding pixel in the partial pattern are compared, matching pattern 4 can be searched for at high speed.

In the above embodiment, the patterns are stored as shading patterns, but the type of preprocessing used when creating the standard pattern 7 is not specified as long as the characteristics of the object can be represented. For example, in addition to the Laplacian filter, a Sochel filter or a Goyen filter can also be used. Furthermore, the size and gradation of the standard two-dimensional pattern used are not specified. Further, if the degree of correspondence between the standard pattern and the partial pattern can be expressed, the calculation of the degree of correspondence is not specified.

Furthermore, in order to speed up the process of searching for matching patterns, the maximum value of the matching degree is updated, and if the maximum value is exceeded during the matching degree calculation process for each partial pattern, subsequent calculations are aborted. It is also possible.

Effects of the Invention As described above, according to the present invention, a standard pattern is constructed from only designated pixels having valid information and is used for pattern position recognition, thereby maintaining the advantages of highly accurate position recognition using gradation patterns, etc. It can increase the processing speed and has a great effect. In experiments, we were able to recognize pattern positions more than three times faster than conventional methods while maintaining accuracy.

[Brief explanation of the drawing]

Figures 1 and 2 show an embodiment of the present invention. Figure 1 is a standard pattern diagram of designated pixels, Part 2 is a partial pattern diagram for creating a standard pattern of designated pixels, and Figure 3 is a diagram of a partial pattern for creating a standard pattern of designated pixels. FIG. 4 is an enlarged view of the standard pattern, and FIG. 5 is an input pattern diagram including the image of the object whose pattern position is to be recognized. 1--------Image of one object 2-1-----Standard pattern 3-1--
−−−−−−−−−−Image of the object of human pattern 4−−−
−−−−−−−−−−−Match pattern 5−−−−−・−
・-111--Specific position 6--1111--Partial pattern 7 for creating a standard pattern of specified pixels-----Specified pixel standard pattern. Figure 1 Figure 2 Figure 7-JIIIifAi 8. Off4 ti9- On Fig. 3 1-Moon 1 Building 2---[Hawk 11g Turn Fig. 4 Fig. 5

Claims (1)

[Claims] (1) A pattern consisting only of designated pixels with valid information in a two-dimensional pattern of a specific part of the target is stored in advance as a standard pattern, and a standard pattern is created from the input partial pattern of the two-dimensional pattern of the position recognition target. By finding the overall best match pattern,
A pattern position recognition method characterized by recognizing a specific position in an input two-dimensional pattern of a position recognition target.