JPS5990178A - Contour recognizing system - Google Patents

Abstract

PURPOSE:To recognize easily and accurately all contours by obtaining the partial contour of an object to be recognized from an observation pattern after converting the background of the object to be recognized into an existing pattern repeating contrast and using the existing information on the contour. CONSTITUTION:A repetitive pattern (a) of black and white which emerge in two directions orthogonal to each other in a fixed cycle is equal to an observation pattern which is obtained by observing an object B to be recognized having the same color and luminance as the white part of a checker A. A part (b) of the contour of the object B obtained from the pattern (a), that is, the boundary line is shown by a solid line between the black part of the checker A and the object B for the pattern (a). While an existing information is provided to show that the contour of the object B is rectangular, the contour of the object B can be completely obtained like (c) by interpolating or extrapolating an a straight line between fragmentary patterns shown in (b).

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a pattern recognition method, and particularly to a contour recognition method for recognizing the contour of a recognition target.

(13) Background of technology Application fields of pattern recognition technology include document or @1
．． There is a system for automatic sorting of registers, etc. In such systems, the target items are usually transported by a conveyor or the like and sorted based on the recognition results of patterns such as symbols, letters, or patterns written on the surface, but the speed and accuracy of recognition are limited. As part of the recognition process, the outline of the recognition target is recognized and recognized in advance.
The work of extracting a single image, so-called "cutting out", is often performed.

(0 Prior Art and Problems) Conventionally, systems for automatic sorting of documents, etc., have conventionally used a plain conveyor, that is, a conveyor without a pattern, and the background of the recognition target is often uniform, so that the background of the recognition target is In such cases, there was a time when the pattern could not be extracted. Even if there is a pattern in the background, it is considered unnecessary noise for recognition of the recognition target. This caused the same problem as above.

■) Purpose of the Invention The present invention aims to easily and accurately recognize the outline of a recognition target by setting the background of the recognition target to a known pattern that is repeated by dl lil, such as a checkerboard pattern. purpose.

(1) Structure of the Invention The contour recognition method according to the present invention uses at least part of observation information regarding the contour of the recognition target obtained by observing the recognition target against the background of a known pattern, and the shape of the contour of the recognition target. The outline of the object to be recognized is recognized based on known information given in advance regarding the object.

(n Examples of the Invention The gist of the present invention will be specifically explained below with reference to Examples.

FIG. 1 is an explanatory diagram of the principle of one embodiment of the present invention, (a> is a black and white repeating pattern that appears at a constant period in two orthogonal directions, that is, recognition that the white part of the checkered pattern A has the same color and brightness. Target Bf: Indicates an observation pattern obtained when observed.

In addition, (b) shows a part of the outline of the recognition target B obtained from the observation pattern shown in (a), that is, the boundary line between the black part of the checkered pattern A and the recognition target B in (a) is shown by a solid line.

On the other hand, if known information is given that the contour shape of recognition target B is rectangular, the recognition target The contour of B can be completely determined as (C1).

Even if the M nii object has exactly the same pattern as the checkered pattern, as shown in (d), if there is even a slight difference in phase or slope between them, the outline can be changed as shown in (e). A portion is obtained and the complete contour can be determined in the same manner as above.

FIG. 2 shows a system block diagram of the embodiment, in which 1 recognizes the checkered pattern as a background.

Obtain the observation pattern as shown in Figure 1 (a).

2 is a median filter that performs noise removal processing on the observed pattern; 3 is a median filter that performs noise removal processing on the observed pattern; 3 is a method for calculating the dense JW gradient by performing window calculation using 1×3 and 3×1 spatial filters on the output pattern of median filter 2; For example, for an observed pattern such as the one shown in FIG. 1(d), a window calculation unit detects a large portion and obtains a pattern such as the one shown in FIG. 1(d).

4 is the back 9 known from the output pattern of the window calculation unit 3.
Remove the component A and create a pattern as shown in Figure 3(b).
), 5 is an extraction unit that extracts only the outer pattern from the output pattern of the processing unit 5 and produces a pattern like the solid line in FIG. This determining section obtains a pattern as shown in FIG. 1(c) by interpolating or extrapolating between the output patterns of the extracting section 5 using known information C given in advance.

According to the above example, the outline of the recognition target can be recognized easily and accurately, except in extremely rare cases where the recognition target has exactly the same checkerboard pattern as the background and the phases match perfectly. .

(Effect of the first rpJ7111 As explained above, according to the present invention, the recognition target can be recognized from the observed pattern without being lost in cost.
By obtaining the outline of at least a part of one elephant, and using the known information about the object given in advance, all the outlines of the object to be recognized can be easily and precisely recognized.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the principle of the present invention - Example 1, FIG. 2 is a system block diagram of an embodiment of the present invention, and FIG. 3 is a functional explanation of a part of FIG. 2.

Claims (2)

[Claims] (1) The recognition target is determined based on at least part of the observation information regarding the contour of the recognition target obtained by observing the recognition target against the background of a known pattern, and the known information given in advance regarding the shape of the contour of the recognition target. A contour recognition method characterized by recognizing contours. (2) The contour recognition method according to claim 1, wherein the known pattern used as the background is a repetitive pattern of shading.