JPH01279379A - Pattern collating device - Google Patents

Abstract

PURPOSE:To realize the real-time collation of patterns with use of a small- capacity table and a simple circuit constitution by performing the fragmentary collation between an input pattern included in an input picture and a reference pattern set previously. CONSTITUTION:Plural cut patterns obtained by setting the horizontal cutting lines at the prescribed positions of a reference pattern are previously registered into a cut pattern table 23. A window setting circuit 18 sets the windows at the collating areas between an input picture and those cut patterns. Then a position checking circuit 24 decides the coincidence or discordance between the pattern in each window and each cut pattern. This deciding action is repeated together with shift of the windows. When the pattern of the window is coincident with either one of cut patterns, the result of collation is decided and delivered. Thus it is possible to perform the real-time collation of patterns with use of a small-capacity table and a sample circuit constitution.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a pattern matching device used, for example, to determine whether or not a predetermined pattern exists in an input image, and particularly relates to a pattern matching device used for determining whether or not a predetermined pattern exists in an input image. The invention compares an input pattern in an input image with a preset reference pattern to find a match between the two patterns.

The present invention relates to a pattern matching device for determining mismatch.

<Prior art> As shown in FIG. 6, a conventional pattern matching device of this type
A reference pattern 1 is registered in the reference pattern table in advance, and a window 2 of a size corresponding to the reference pattern 1 is set on the input image 3 and the pattern in the window 2 is compared with the reference pattern 1 while being moved. Then, it is determined whether the two patterns match or do not match, and thereby it is determined whether or not there is a dog covert turn 4 that matches the reference pattern 1 in the input image 3.

FIG. 7 shows an example of a device for realizing the above operation in real time. In the figure, a television camera 5 is used to obtain the above-mentioned input image 3, and a binarization circuit 6 is used to input a video signal from the television camera 5 and binarize it. The data is given to window setting circuit 7. This window setting circuit 7 consists of a multi-stage shift register 8, a plurality of delay circuits 9, and a synchronization signal generation circuit IO, and the shift register 8 has a bit corresponding to the horizontal length of the window 2. In addition, only the number of stages corresponding to the vertical length of the window 2 is used. Each delay circuit 9 sequentially delays the binary image data given to the shift register 8 at each stage by bits corresponding to one horizontal scanning period, and sets the binary image data at each inter-row position in the shift register 8 at each stage. .

Each bit data of the shift register 8 of each stage is given to the reference pattern table 11, where the pattern in the window 2 and the reference pattern 1 are compared one after another to determine whether they match or not. It is then determined whether or not there is an input pattern 4 that matches the reference pattern 1 in the input image 3.

<Problems to be Solved by the Invention> However, in the above-mentioned pattern matching device, assuming that the window 2 has 10 bits each in the vertical and horizontal directions as shown in FIG. 8, the reference pattern table 11 has a capacity of at least 2100 bits. Moreover, in order to realize pattern matching in real time, 100
An elemental shift register 8 and a nine-stage delay circuit 9 are required. In particular, since the reference pattern table 11 requires a huge capacity, if the pattern to be matched becomes large, pattern matching in real time becomes virtually impossible.

This invention was made with attention to the above problem, and provides a new pattern matching device that can realize real-time pattern matching using a small-capacity table and a simple circuit configuration by performing pattern matching piecemeal. The purpose is to

Means for Solving the Problems In order to achieve the above object, the pattern matching device of the present invention registers a plurality of cutting patterns obtained by setting horizontal cutting lines at predetermined positions of the reference pattern. means for setting and transitioning a window at a matching portion of the input image with the cutting pattern; means for determining whether a pattern in the window matches each cutting pattern; The apparatus includes means for determining and outputting the result of matching the input pattern against the reference pattern based on the positional relationship between each pattern in the determined window and each cutting pattern.

<Operation> Prior to pattern matching, horizontal cutting lines are set at a plurality of locations on the reference pattern to obtain a plurality of cutting patterns, and these cutting patterns are registered in the memory in advance.

Next, when an input image is given, a window is set at a portion of the input image that matches the cutting pattern, and it is determined whether the pattern in the window matches or does not match each cutting pattern. This determination operation is repeated while moving the window. When it is determined that any pattern in the window matches a cutting pattern, the result of matching the input pattern against the reference pattern is determined and output based on the positional relationship between each pattern in the window that has been determined to be a match and each cutting pattern. .

With such a fragmentary matching method, real-time pattern matching can be realized using a small-capacity table and a simple circuit configuration.

<Embodiment> FIGS. 1 and 2 show an example of the configuration of a pattern matching device according to an embodiment of the present invention, and FIGS.
The figure shows the principle of the pattern matching device of the present invention.

As shown in FIG. 3, the illustrated pattern matching device sets horizontal cutting lines 10 to 12 at predetermined locations of the reference pattern I2, and creates a plurality of cutting patterns -〇, 〇,
Find Wl, W2 and use these cutting patterns -0, Wl
, W2 are registered in advance in the cutting pattern table to be described later.

Next, when an input image 13 as shown in FIG. 4 is given, a window 14 is set on this input image 13 for comparison with the cutting pattern, and this
Any of the patterns in 4 is the cutting pattern WO, Wl,
It is determined whether or not it matches W2. This discrimination operation is repeatedly performed while moving the window 14 in the direction shown by the arrow in the figure, and as a result, at the position (Xa'+Yo), the pattern PO in the window 14 becomes the first cutting pattern WO, and Further, at the position (X,,Y,), the pattern P1 in the window 14 becomes the second cutting pattern W1, and furthermore, at the position (Xo, Yz), the pattern P2 in the window 14 becomes the third cutting pattern-2. , each will match. When this match determination is performed, the positional relationship between each pattern PO, PI, and P2 and each cutting pattern WO are determined.
, Wl, and W2 are the same, and if they are the same, it is determined that the input pattern 15 matches the reference pattern 12, and the determination result is output.

Note that the input pattern 15 can be compared with the reference pattern 12 even when the input pattern 15 is rotated. In order to perform such rotation pattern matching, as shown in FIG. Wl and W2 must be registered in the cutting pattern table in advance.

FIG. 1 shows an example of a pattern matching device that realizes the above matching operation in real time.

In the figure, a television camera 16 images the object to be matched and generates the input image 13 described above. The binarization circuit 17 inputs a video signal from the television camera 16, binarizes it, and outputs the binary image data to the window setting circuit 18. This window setting circuit 18 includes a shift register 19 having bits corresponding to the length of one win 14, and a synchronization signal generation circuit 22 which supplies a synchronization clock to this shift register 19, an X coordinate counter 20, and a Y coordinate counter 21. Binary image data contained within the window 14 of the input image 13 is set in the shift register 19. Note that one bit of the shift register 19 corresponds to one pixel of the input image 13.

The cutting pattern table 23 includes the cutting patterns WO,
Wl, W2 are registered in advance (this is for the purpose of registering each bit data of the shift register 19, that is, the pattern in the window 14, to this cutting pattern table 23, the pattern and each cutting pattern WO, W
1 and W2 are performed to determine whether they match or do not match.

As a result, when the pattern within the window 14 matches any of the cutting patterns WO, Wl, W2, a result output to that effect is provided to the position inspection circuit 24.

The position inspection circuit 24 uses position data provided by the X coordinate counter 20 and the Y coordinate counter 21 to determine whether or not the positional relationship between the patterns for matching determination is the same as the positional relationship between the cutting patterns WO, Wl, and W2. If they are the same, input pattern 1
5 determines whether the pattern matches the reference pattern 12 and outputs the determination result.

FIG. 2 shows a specific example of the position inspection circuit 24, which includes two latch circuits 25, 26 and two adders 27.2.
B, three comparators 29°30.31, three D-
Latch circuits 32, 33° 34, three AND circuits 35,
Contains 36.37. Of these, latch circuits 25, 2
6, adder 27.28, comparator 29, 30.31
The AND circuits 35 and 36 are for generating a reference signal representing the positional relationship between each cutting pattern and the sails Wl and W2, and the D-latch circuits 32, 33 and 34 use this reference signal. This is to determine whether or not the force Z is the same between the positional relationship between the patterns related to the coincidence determination and the positional relationship between the cutting patterns WO, kl, and W2. The AND circuit 37 is for integrating the judgment results of the D-latch circuits 32, 33, and 34 and determining whether the input pattern matches the reference pattern.

Next, to explain the circuit operation of FIGS. 1 and 2, the window 14 moves on the input image 13 by the shift operation of the shift register 19, and the pattern within the window 14 at each shift position is Cutting pattern
It is determined each time with reference to the cutting pattern table 23 whether or not they match with 〇, Wl, and W2.

When the pattern in the window 14 matches the first cutting pattern WO, the cutting pattern table 23 outputs a matching output 10 to the position inspection circuit 24. This − scattered power i. is given to each latch circuit 25 and 26 of the position inspection circuit 24, the count value X of the X coordinate counter 20 at that time
and the count value Y of the X coordinate counter 21 are latched. Said-dispersed power i. is also given as a clock input to the D-latch circuit 32, which causes the D-latch circuit 32 to latch the fixed data input of rlJ and
The detection result indicating that the cutting pattern -〇 has been detected is output to the AND circuit 37.

The data latched by the latch circuit 25 is provided to a comparator 29. This comparator 29 judges whether the counted value of the X coordinate counter 20 matches the launch data or not, and when both match, the -spread output is sent to the AND circuit 3.
5.36.

When the latch data of the latch circuit 26 is given to each of the two adders 27 and 28, one of the adders 27 calculates the Y-direction offset value (positional deviation) of the first cutting pattern of the second cutting pattern Wl. amount) is added to this. Further, the other adder 28 adds a third value to the latch data of the latch circuit 26.
The Y-direction offset value of cutting pattern-2 with respect to the first cutting pattern WO is added, and each addition output is given to two comparators 30 and 31.

Each comparator 30, 31 determines whether the counted value Y of the Y' coordinate counter 21 and the addition output from each adder 27, 28 match, and when they match, each -
The scattered output is given to AND circuits 35 and 36. When one of the AND circuits 35 receives the matching outputs from the comparators 29 and 30, and the other AND circuit 36 receives the matching outputs from the comparators 30 and 31, the output becomes "1". This output signal is provided as a data input to D-latch circuits 33 and 34.

Now, when the counted value X of the X-coordinate counter 20 matches the latch data of the latch circuit 25, and the counted value Y of the X-coordinate counter 21 matches the addition output of the adder 27, both the comparators 29 and 30 output a matching output. AND circuit 35
, the output will be "1". At this time, when the cutting pattern table 23 determines that the pattern in the window 14 matches the second cutting pattern W1 and provides the -spread output 11 to the D-latch circuit 33 as a clock input, the output from the AND circuit 35 is The data input of “1” is latched, and a detection result indicating that the second cutting pattern Wl has been detected is output to the AND circuit 37.

Next, when the counted value of the X-coordinate counter 20 matches the launch data from the latch circuit 25, and the counted value of the X-coordinate counter 21 matches the addition output of the adder 28, both the comparators 29 and 31 output the matching output as a logic signal. It is applied to the product circuit 36, and its output becomes rlJ. At this time, the cutting pattern table 23 indicates that the pattern in the window 14 is the third
It is determined that the cutting pattern W2 matches the cutting pattern W2, and the -spread force 1
2 as a clock input to the D-latch circuit 34, the data input of "1" from the AND circuit 36 is latched, and the detection result indicating that the third cutting pattern 2 has been detected is output to the AND circuit 37. Output to.

As a result, the AND circuit 37 sends out a result output indicating that the input image 13 has an input cover coin 15 that matches the reference pattern 12 when the three inputs are all "1".

<Effects of the Invention> As described above, the present invention registers in advance a plurality of cutting patterns obtained by setting horizontal cutting lines at predetermined positions of a reference pattern, and compares the input image with the cutting patterns. While setting a window at a location and moving, it is determined whether the pattern in the window matches or does not match each cutting pattern, and the input pattern is Since the matching results against the reference pattern are determined and output, real-time pattern matching can be achieved with a small capacity table and simple circuit configuration, and even if the matching pattern is large, real-time pattern matching is possible. It has a remarkable effect of achieving the purpose of the invention.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a circuit configuration of a pattern matching device according to an embodiment of the present invention, FIG. 2 is a block diagram showing a specific example of a position inspection circuit, and FIGS. 3 to 5 are principles of the present invention. 6 is a principle explanatory diagram showing the principle of the conventional example, FIG. 7 is a block diagram showing the circuit configuration of the conventional example, and FIG. 8 is an explanatory diagram illustrating the capacity of the reference pattern table. It is. 12...Reference pattern 13...Input image 1
4... Window 15... Input pattern 19... Shift register 23... Cutting pattern table 24... Position inspection circuit

Claims (1)

[Scope of Claims] A pattern matching device for matching an input pattern in an input image with a reference pattern, wherein a plurality of cutting patterns obtained by setting horizontal cutting lines at predetermined positions of the reference pattern are provided. means for registering; means for setting and transitioning a window at a matching location of the input image with the cutting pattern; and means for determining whether a pattern in the window matches or does not match each cutting pattern; . A pattern matching device comprising: means for determining and outputting a matching result of an input pattern against a reference pattern based on the positional relationship between each pattern in the window and each cutting pattern that has been determined to be a match.