JPH07218446A - Device and method for inspecting pattern of logo mark or the like and device for preparing pattern dictionary of logo mark or the like - Google Patents

Abstract

PURPOSE:To inspect a pattern even when the pattern is such a pattern that adjacent characters overlapping upon another by registering reference patterns, etc., segmented at every small block. CONSTITUTION:Reference patterns obtained by segmenting the reference pattern of a logo mark, etc., at every segmenting area are registered as dictionary patterns. At the same time, each information indicating the position and size of each segmenting area and division of each small block is registered. Then the picture of the pattern of a logo mark, etc., to be inspected is taken and the taken video pattern is divided into the segmenting areas and small blocks based on each registered information. Thereafter, the small block segmenting pattern is matched to the reference patterns. Namely, a CPU 1 performs these processes on a pattern to be inspected which is an actual image fetched to an auxiliary memory 3 from a TV camera 7 and, at the same time, performs pattern matching, etc., against the dictionary patterns. Thus the propriety of the pattern to be inspected is discriminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern inspection device for inspecting a special pattern such as a logo mark.

[0002]

2. Description of the Related Art Characters may be directly engraved or printed labels may be attached to various containers such as bottles and cans. When detecting such characters and labels, it is essential to cut out the characters from the captured image.

FIG. 2 shows an example thereof. The case of a character string "HITAXXX" as a video character is shown. In order to cut out each character of H, I, T, A, and XXXXX from each character, first, the character image is projected horizontally and vertically. In the vertical direction, a distribution image of integrated values along the height direction of those characters is obtained, and in the horizontal direction, a distribution image of integrated values along the horizontal direction of each character is obtained. If each character is printed separately, the distribution image in the horizontal direction reflects the size of the character in the vertical direction. On the other hand, the vertical distribution image reflects the height of the character. Therefore, by cutting out the video characters with the width of the distribution image in the vertical direction and the width of the distribution image in the horizontal direction for each character, H, I, T, A, XX
7 characters of XX will be cut out one by one. Characters are inspected by comparing each cut out character with a standard character.

[0004]

FIG. 2 shows an example in which the distribution image in the horizontal direction has an independent distribution for each character. However, in the case of special characters such as logo marks and decorative characters, adjacent characters may overlap each other.
This is shown in FIG. 3 as an example of a logo mark for “HITAXXX”. It can be seen that adjacent characters overlap each other. Therefore, when this is projected in the horizontal direction, one distribution image is obtained, and it cannot be used for cutting out character by character.

An object of the present invention is to provide a pattern inspecting apparatus and method and a dictionary creating apparatus capable of inspecting patterns even in a pattern in which adjacent characters overlap each other.

[0006]

According to the present invention, a reference pattern cut out for each small block is registered as a dictionary pattern for each cutout area of a reference pattern such as a logo mark, and the position and size of each cutout area are In addition, a first means for registering each piece of information indicating the division of a small block, a second means for imaging a pattern such as a logo mark to be inspected, a cutout area of this image pattern, and a small area in each cutout area. Blocking is performed based on each information registered above,
The third means for cutting out a pattern according to a small block in each cutout area, the pattern matching between the small block cutout pattern in each cutout area, and the small block cutout reference pattern in the corresponding cutout area of the dictionary pattern is performed. Disclosed is a fourth means for performing cutout area correspondence and small block correspondence, and an inspection apparatus for a pattern such as a logo mark.

Further, according to the present invention, since the registered information is used for registration, the reliability of the pattern matching may be lowered. Therefore, when cutting out a small block from the inspection pattern, the shift is performed while shifting left and right. It is assumed that each cutout pattern is used, and the pattern size in the cutout section may have various sizes, so normalization is performed.

Furthermore, the present invention provides an inspection method for inspecting a pattern such as a logo mark to be inspected, by cutting out a reference pattern into a cutout region and a small block in this region, and cutting out the pattern cut out for each small block. It is registered as a dictionary pattern, and further, the position and size of each cutout area and the size of a small block are registered, an actual inspection pattern is imaged by a TV camera, and this image is recorded as the registered cutout area. According to the position and size of the small block and the size of the small block, the cutout region and the small block are cut out, and the cutout pattern for each cutout region and each small block cut out from this actual inspection pattern and the corresponding cutout pattern of the dictionary. Disclosed is a pattern inspection method for a logo mark or the like, in which the pattern matching is performed for inspection.

Further, according to the present invention, a pattern such as a logo mark to be inspected is inspected. In the inspection method, this inspection pattern is labeled and divided into cutout areas,
Further, there is disclosed a method of inspecting a pattern such as a logo mark in which the inside of each cutout area is divided into small blocks, and the pattern is inspected by performing pattern matching processing between the pattern of division of the small blocks and a reference dictionary pattern.

Further, according to the present invention, there is provided a first means for projecting a pattern such as a reference logo mark in the horizontal and vertical directions to obtain a horizontal projection distribution image and a vertical projection distribution image, and a horizontal projection distribution image and a vertical projection distribution image. An area that overlaps the image is used as a cutout area, each cutout area is divided into small blocks, and a second means for cutting out a pattern for each small block, and a cutout pattern for each small block for each cutout area are defined in a dictionary. Disclosed is a device for creating a pattern dictionary such as a logo mark, which includes a third means for registering a pattern as well as a positional relationship on the image between the cutout regions.

[0011]

According to the present invention, the cutout area and the pattern cutout by dividing it into small blocks are registered as a dictionary pattern for the reference pattern, and information indicating the positional relationship between them is registered, and this is inspected. By using this for pattern cutting and pattern matching, it is possible to inspect special overlapping patterns such as logo marks.

Further, according to the present invention, when the inspection pattern is cut out, the matching ability of the pattern matching is enhanced by performing left-right shift and normalization.

Further, according to the present invention, information indicating the dictionary pattern, positional relationship, etc. is stored.

[0014]

FIG. 4 is a diagram showing a method of creating a dictionary pattern according to the present invention. The reference logo mark is used as a dictionary pattern. In FIG. 4A, first, a reference logo mark is visualized and saved (F ₁ ). As an example of a logo mark, a circle mark and "HITAXXX, H0256"
An example consisting of a combination of The character width of this image is expanded in the horizontal direction (character matching processing) (F ₂ ). This ensures that the letters overlap. This is realized by a kind of filter processing.

An example in which this character matching process is realized by a filter process will be described with reference to FIG. FIG. 5 (a) shows the number string "417.
3 ”logo mark example (For simplicity, it is binarized. Therefore, the character part is“ 1 ”, the non-character part is“ 0 ”.
Is displayed), and when cutting out as it is,
If “4”, “17”, and “3” can be separated on the horizontal projection information, three cutouts of “4”, “17”, and “3” will be made. Or, "4" and "1" approach each other,
If "7" and "3" are close and cannot be separated,
It is the entire cutout of "4173". Either way, Figure 5
With the logo mark such as (a), the cutout becomes unstable.
Therefore, the horizontal expansion filter as shown in FIG.
Process the logo mark in (a). The horizontal expansion filter of FIG. 5C is a 1 × 4 spatial filter having a size of 4 pixels in the horizontal direction and a size of 1 pixel in the vertical direction. This filter is a filter that if there is at least one "1" for the four pixels in the horizontal direction, the remaining three pixels are all "1". By performing the filter processing while raster-scanning the logo mark of FIG. 5A with this filter, an image with an enlarged width in the horizontal direction can be obtained as shown in FIG. The so-called characters are overlapped and the instability for cutting out as described above is eliminated, and block cutting out with the size of "4173" as one block under the overlapped state becomes possible.

However, since the lateral width is enlarged, FIG.
The horizontal width of FIG. 5B is enlarged as compared with the horizontal width of the actual logo mark of FIG. By enlarging the width as shown in Fig. 5 (b),
It is a problem if adjacent blocks may overlap each other. Therefore, the spatial filter is set to 1 in the example in which the blocks constituting the logo mark are close to each other.
The filter size may be 1 × 3 or 1 × 2 instead of × 4. Also, various widening filters such as 2 × 4 and 2 × 3 can be used instead of 1 × 4 and 1 × 3.

Next, a labeling process is performed (F ₃ ). The labeling process is a pre-process for cutting out characters, and obtains horizontal and vertical projected distribution images for the logo mark after character alignment by the method shown in FIGS. 2 and 3, and the horizontal and vertical components of this distribution image. Is defined as a cutout area, and labeling such as labels 1, 2, ... Is performed to distinguish each cutout area. In many cases, the cut-out area is usually performed on a character-by-character basis. However, in this embodiment, character matching is performed, so that a certain group of adjacent characters shown in FIG. 5B becomes the cut-out area. These are called blocks.

Next, the object to be processed is returned to the saved image (F ₄ ). On this saved image, block cutting is performed according to the block position and block size (block position and block size are expressed by labeling) obtained in the flow F ₂ . Thus, the saved video will be cut out in several blocks. A small block is cut out (creation of a window) in each block which is a cutout area (F ₅ ). The small block cutout is a process of further dividing a block and cutting out a character pattern (including not only a character but also a part of the character) in the subdivided section. The cut-out character patterns of the blocks and the small blocks within the blocks are used as dictionary patterns (F ₆ ).

It should be noted that the horizontal enlargement of FIG.
There is a problem that the width becomes larger than that of the real logo mark of (a), and the cutout area of the saved image becomes a cutout area larger than the block area of the real logomark. For this measure, for the block size obtained in FIG.
The enlargement ratio by the used filter may be obtained in advance, and the block size reduction process may be performed so as to reduce the enlargement ratio. The magnification is not accurate and may be a rough value.

Furthermore, the positional relationship between the marks constituting the logo mark cannot be specified only by the dictionary pattern. Therefore,
Distance data between each block is obtained and registered with the dictionary pattern.

FIG. 4B shows a concrete example of FIG. The standard logo mark is visualized and used for filtering (character matching) and saved (F ₁ ). The character width in the horizontal direction of the logo mark is expanded by matching the characters (F ₂ ). Thereby, the reference image, as shown in F ₂ in FIG. 4 (b), characters are arranged with a certain degree spread laterally (hita ××× and H
0256) approach each other and overlap. After obtaining the horizontal and vertical distribution images of the logo mark after the character alignment, the cutout area is determined from this (F ₃ ). HITA by matching letters
Each of XXX and H0256 is reliably ensured as an independent cutout area.

The cutout area is three blocks indicated by dotted lines in FIG. Area of "Maru mark", "HITA
This is an area of “HXX” of “XXX”. Next, the entire video area including the cutout area in which characters are matched is returned to the original size of the video saved previously. Allocate the labeled cutout area to the saved logo mark image in the original size. When wearing this split, performs small blocks cut for each of the regions (F ₄ ~F _7). The size and number of small block cutouts are arbitrary. In the example of FIG. 4B, as indicated by a dotted line in the block, “HITAxx
“X” indicates an example of forming four small blocks, “H0256” indicates an example of forming three small blocks, and “Mull mark” indicates an example of forming four small blocks. Patterns such as characters in these small block sections are registered as dictionary patterns.

Further, the distance between the three cutout areas is calculated and registered. In the figure, "HI" is the standard
TA ×× ”is x _{1 in} the horizontal axis (x axis) direction and the vertical axis (y axis)
Similarly, y ₁ and “H0256” in the direction are assumed to exist at a distance of x ₂ and y ₂ . These x ₁ , y ₁ , x ₂ , y ₂ are registered in correspondence with each block. In addition to this, the dictionary pattern also stores the size of the cutout area, the size of the small block, and the position. These pieces of information other than the dictionary pattern are used for cutting out the inspection pattern in FIG.

FIG. 1 is a diagram showing a flow chart of the inspection process. FIG. 1 (a) is the flow chart itself, and FIG.
(B) is a figure which shows a specific example. The inspection target shall be the logo mark printed on the can or bottle. First, read the logo mark with the TV camera (f ₁₀ ). The reference position of the read logo mark is detected. Next, specify the cutout area block,
At the same time, the inside of the block is subdivided to create a block window (F ₁₁ ). For the specification of the cut-out area block and the block window, it is preferable to directly apply the information such as the position and size of the cut-out area block and the block window registered when the dictionary was created. This is because efficient cutting is possible. However, the same method as that used at the time of creating the dictionary according to FIG. 2 may be applied to this video inspection logo mark to be obtained.

Next, in FIG. 1A, pattern matching is performed between the dictionary pattern created in FIG. 4 and the pattern cut out from the inspection logo mark (F ₁₂ ). This pattern matching is performed by "Maru", "HITAxx"
For each of the cut-out area blocks of “×” and “H0256”, the processing is performed for each small block forming the block. Various known pattern matching methods can be used. As a result of the pattern matching, the degree of coincidence is obtained, and it is checked whether or not the degree of coincidence is the judgment value or more (F ₁₃ ). If it is equal to or larger than the judgment value, the character pattern in this small block (block window) is recognized as corresponding to the dictionary pattern at that time, and the process proceeds to step F ₁₄ .

On the other hand, unless the degree of coincidence determination value or more, moves to shift processing F _30, the how to cut small blocks and compares the determined value by variously changing, intended degree of coincidence than the determination value Check if there is. The shift process F ₃₀ includes steps F ₁₇ , F ₁₈ , and F ₁₉ . An example of this shift processing is shown in FIGS. First, in step F ₁₇ , the window is shifted in the left-right direction and the pattern matching process is executed each time. Degree of coincidence is checked whether the determination value or more in step F _18, if the determination value or more stops shift processing proceeds to step F _14. If the degree of coincidence at the time of shift is less than or equal to the judgment value, the shift content is updated in step F ₁₉ , and the pattern matching is performed again in step F ₁₇ to judge the degree of coincidence (step F ₁₈ ).

Examples of this shift processing are shown in FIGS.
In FIG. 6, it is assumed that the dictionary pattern is “HI”, whereas the inspection pattern “HITAXXX” exists. When a small block is cut out from this inspection pattern at the position shown in FIG. 6, the dictionary pattern is "HI", whereas the small block cutout pattern "H" from the inspection pattern is the entire character. However, "I" is a missing pattern of only a part of it. Therefore, the desired degree of coincidence cannot be obtained even if pattern matching between the two is performed. Therefore, as shown in FIG. 7, from the state shown in (a),
The degree of coincidence is obtained by performing the right shift as shown in (b), and if this fails, the degree of coincidence is obtained by performing the left shift as shown in (c). In the figure, it can be visually seen that the degree of coincidence is large by the left shift of (C). If this (C) does not work, perform a further left shift. In this way, the left and right shifts are performed the specified number of times, and it is checked whether or not there is a degree of coincidence larger than the determination value. If there is no degree of coincidence that is greater than the judgment value, the process proceeds to step F ₂₀ , and it is judged that the printing is defective (or unreadable).

Returning to the explanation of FIG. Figure 1 checks whether calculation of the matching degree for all windows of one of the cut-out region block (small block segment) is finished in (b), and continues the process in step F ₁₀ to F ₁₉ until the end. When the processing for all the windows is completed, it is determined that the entire cut-out area block has a degree of coincidence larger than the determination value over all the windows (small block divisions), and it is determined that the printing is normal (step F ₁₅ ).
Finally, the result is output (step ₁₆ ).

FIG. 1B shows a concrete processing example including the shift processing shown in FIGS. No particular explanation is necessary.

As the logo mark serving as the reference pattern, the size of the entire character and the thickness of the line are normalized, but the printed logo mark is the image itself captured by the TV camera. However, in the actual printing, the size of the entire character of the print pattern and the thickness of the line vary slightly depending on the state of the printing machine. Therefore, the mismatch may not be ignored in the simple pattern matching process. In such a case, it is advisable to normalize the image captured by the TV camera for each character. This normalization for each character is performed on the character pattern in the section divided into small blocks. The normalization is performed by enlarging or reducing the character pattern in each section. This enlargement / reduction may be made uniform in the vertical and horizontal directions, or may be uneven in the horizontal and vertical directions. As the position of the normalization on the step in FIG. 1, it may be inserted between F ₁₀ and F ₁₁ . Then, a plurality of normalization constants are prepared (for example, _four normalization constants m ₁ × n ₁ , m ₂ × n ₂ , m ₃ × n ₃ , and m ₄ × n ₄ where m ₁ ~ m ₄ is a horizontal enlargement or reduction ratio, n _{1 to} n ₄ are vertical enlargement or reduction ratios, m
₍ Examples such as ₁ = n ₁ are equal examples in vertical and horizontal directions.) Four normalizations are performed according to these four types of normalization constants, and processing such as pattern matching with a dictionary pattern is performed for each normalized character (F
₁₁ to F ₁₉₎ performs, for a match degree, if any closest, the printing is considered normal.

Alternatively, the pattern matching may be performed sequentially in the order of four normalizations, and the pattern matching may be terminated when a degree of coincidence larger than the determination value is obtained.

It is to be noted that the normalization is performed in units of block divisions in the cutout area. However, normalization of one cutout area as a whole is not a problem if the cutout area is not divided into small blocks. It is not preferable for blocks to be divided. The reason is that there are multiple characters and the like in one cutout area, and the sizes and positions of individual characters and the like are often different, and normalization of the entire cutout area results in unreliability. is there.

The above is an example of one cut-out area block, and these processes are performed for all cut-out area blocks. At this time, it is necessary to specify the cutout positions (coordinates) of all the cutout areas of the inspection pattern, and this specification is performed by reading the distance data itself registered in step F ₇ of FIG.

An embodiment of the character pattern inspection apparatus of the present invention is shown in FIG. In this embodiment, the common bus 10 has a CPU
1, main memory 2, auxiliary memory 3, image memory 4 and CRT
5, the interface 6, the TV camera 7, the keyboard 8 and the mouse 9 are commonly connected, and constitutes a so-called microcomputer. The image captured by the TV camera 7 is taken into the auxiliary memory 3 via the interface 6. The dictionary and the distance between the area blocks shown in FIG. 4 are already stored in the auxiliary memory 3. CPU1
According to the software of the main memory 2, the processing of FIG. 1A is performed on the inspection pattern which is the actual image latched in the auxiliary memory 3 and the processing such as pattern matching with the dictionary pattern. Then, the quality of the inspection pattern is determined. The image memory 4 is an image storage memory for displaying on the CRT 5, and is used for displaying the image of the TV camera, displaying the process diagram of FIG. 1, displaying the pass / fail result, and the like. The keyboard 8 and mouse 9 are used for man-machine interface. That is, it is used for various operation instructions and input instructions.

Although the example of the logo mark has been described, the present invention can be applied to general patterns in which it is impossible to cut out each character. In addition, although symbols and numbers other than letters can be naturally applied, they can also be applied to general figure inspection. It can also be applied to the inspection of patterns such as characters other than printing.

[0036]

According to the present invention, when inspecting a logo mark or the like in which it is impossible to cut out character by character, a cutout area is set for each group of characters, and a small block is further added to this cutout area. The pattern matching comparison is performed by classifying into. As a result, it becomes possible to perform an inspection such as printing of a pattern in which characters cannot be cut out due to overlapping characters.

[Brief description of drawings]

FIG. 1 is a diagram showing a processing flowchart of the present invention.

FIG. 2 is an explanatory diagram of conventional character cutting.

FIG. 3 is an explanatory diagram of conventional character cutting.

FIG. 4 is a diagram showing a flowchart for creating a dictionary according to the present invention.

FIG. 5 is an explanatory diagram of character matching.

FIG. 6 is a diagram showing the necessity of shift processing according to the present invention.

FIG. 7 is a diagram showing various examples of shift processing according to the present invention.

FIG. 8 is a diagram showing an embodiment of the inspection device of the present invention.

[Explanation of symbols]

 1 CPU 2 Main Memory 3 Auxiliary Memory 4 Image Memory 5 CRT 6 Interface 7 TV Camera 8 Keyboard 9 Mouse 10 Common Bus

Claims (8)

[Claims] 1. A reference pattern cut out for each small block is registered as a dictionary pattern for each cut-out region of a reference pattern such as a logo mark, and the position and size of each cut-out region and the division of each small block are indicated. First means for registering information, and second means for imaging a pattern such as a logo mark to be inspected
Means for dividing the video pattern into small blocks in the cutout area and each cutout area based on the registered information, and cutting out a pattern in each cutout area according to the small blocks.
Means for performing pattern matching between the small block cutout pattern in each cutout area and the small block cutout reference pattern in the corresponding cutout area of the dictionary pattern, corresponding to the cutout area and the small block. An inspection device for patterns such as logo marks. 2. A reference pattern cut out for each small block is registered as a dictionary pattern for each cut-out area of a reference pattern such as a logo mark, and the position and size of each cut-out area and the division of the small block are indicated. First means for registering information, and second means for imaging a pattern such as a logo mark to be inspected
And the cut-out area and the small blocks in each cut-out area of this video pattern based on the registered information, and while shifting the small blocks to the left and right in each cut-out area, the pattern is formed at each shift. Third means for cutting, a small block cutting pattern for each shift while shifting to the left and right in each cutting area, and a small block cutting reference pattern in the corresponding cutting area of the dictionary pattern,
The pattern inspection device for a pattern such as a logo mark, which comprises the fourth means for performing the pattern matching described above in correspondence with the cutout area and the small block while shifting. 3. A reference pattern cut out for each small block is registered as a dictionary pattern for each cut-out area of a reference pattern such as a logo mark, and the position and size of each cut-out area and the division of each small block are indicated. First means for registering information, and second means for imaging a pattern such as a logo mark to be inspected
And the cut-out area and the cut-out area in each cut-out area of this video pattern based on the registered information, the pattern is cut out in accordance with the small blocks in each cut-out area, and the cut-out pattern is normalized. Pattern matching of the normalized small block cutout pattern in each cutout area and the small block cutout reference pattern in the corresponding cutout area of the dictionary pattern,
An inspection device for a pattern such as a logo mark, which comprises a fourth means for cutting out areas and small blocks. 4. A reference pattern cut out for each small block is registered as a dictionary pattern for each cut-out area of a reference pattern such as a logo mark, and the position and size of each cut-out area and the division of each small block are indicated. First means for registering information, and second means for imaging a pattern such as a logo mark to be inspected
And the cut-out area and the small blocks in each cut-out area of this video pattern based on the registered information, and while shifting the small blocks to the left and right in each cut-out area, the pattern is formed at each shift. Third means for normalizing and cutting, a small block cutting pattern after normalization for each shift while shifting left and right in each cutting area, and a small block cutting reference pattern in the corresponding cutting area of the dictionary pattern A pattern inspection device for a pattern such as a logo mark, which comprises a fourth means for performing the pattern matching of and on the cutout area and the small block while shifting. 5. The inspection device for a pattern such as a logo mark according to claim 3, wherein the normalization is performed for each of a plurality of different types of normalization. 6. An inspection method for inspecting a pattern such as a logo mark to be inspected, wherein a cut-out area and a small block in this area are formed for a reference pattern, and the cut-out pattern for each small block is used as a dictionary pattern. The position and size of each cutout area and the size of a small block are registered in advance, an actual inspection pattern is captured by a TV camera, and this image is recorded in the position of the registered cutout area and According to the size and the size of the small block, the cutout area and the small block are cut out, and the pattern matching between the cutout pattern for each cutout area and each small block cut out from this actual inspection pattern and the corresponding cutout pattern in the dictionary is performed. A pattern inspection method for logo marks, etc. 7. An inspection method for inspecting a pattern such as a logo mark to be inspected, wherein the inspection pattern is labeled and divided into cutout regions, and the inside of each cutout region is divided into small blocks, A pattern inspection method such as a logo mark for inspecting a pattern by performing a pattern matching process between the pattern of the division of the small blocks and the reference dictionary pattern. 8. A first means for obtaining a horizontal projection distribution image and a vertical projection distribution image by projecting a pattern such as a reference logo mark in the horizontal and vertical directions, and a horizontal projection distribution image and a vertical projection distribution image, respectively. The overlapping area is used as a cutout area, each cutout area is divided into small blocks, and a pattern is cut out for each small block.
And a third means for registering the cut-out pattern for each small block for each cut-out area as a dictionary pattern, and for registering the positional relationship on the image between the cut-out areas, and a pattern such as a logo mark. Dictionary creation device.