JPH11224338A - Character judgement method and printed character inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely judge a printed character by obtaining a direction code image along a contour from an input image, comparing the direction code image and a standard code character pattern and judging a character in the input image. SOLUTION: A sensor 4 detects the arrival of a carton box 2 and a video camera 5 picks up the image of the printing part. An inspection device 6 inputs the picked-up image of the camera 5, detects a direction code for indicating the direction of the contour line of the image for the respective images including the character and obtains the direction code image. The correlation processing of the direction code character pattern of the character for standard printing read from a dictionary memory, an expanded direction code character pattern for the expanded character and the input direction code image is performed. When an obtained correlation value is equal to or more than a stipulated value, the character is defined as normal printing. When it is less than the stipulated value, it is defined as abnormal printing and discharge from a conveyor 1 is performed by a discharge machine 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a character judging method and an inspecting apparatus, and more particularly to a judging method and an inspecting apparatus suitable for judging the normal / abnormal of a seal of a seal character.

[0002]

2. Description of the Related Art In an automatic inspection system on a transport line for inspecting a character stamped by an ink jet printer, there is a problem that the size of the character changes due to a change in the moving speed of the line, and the position of the character also slightly changes. It was necessary to cut out and normalize each character and then check it against a dictionary pattern of normal characters.

[0003]

However, for this purpose, when printing, it is necessary to separate the characters so that the characters do not overlap even if the characters fluctuate, and it is not possible to perform inspection if a pattern other than the characters overlaps the characters. was there.

[0004] An object of the present invention is to provide a character judging method capable of reliably judging a stamp character.

Another object of the present invention is to provide a function of a stamping machine which does not erroneously check that the stamping machine is defective even if the characters are not separated from each other in a character inspection for examining the quality of the stamping machine. To provide an inspection device capable of inspecting the data.

[0006]

According to the present invention, a direction code image along a contour is obtained from an input image including a character to be determined as a normal character or not, and the direction code image and a standard direction code character pattern are obtained. A character determination method for determining a character in an input image by comparing.

Further, the present invention provides a character stamping means, a means for photographing an area including a stamped character of an object stamped by this means, a dictionary memory for storing direction code character patterns for standard characters, Means for obtaining a direction code image along the contour in the input image, means for correlating the obtained direction code image with the direction code character pattern read from the dictionary memory, and checking whether or not the seal is normal; A seal character inspection apparatus comprising:

Further, the present invention provides a character stamping means, means for imaging an area including a stamped character of an object stamped by the means, a direction code pattern for a standard character, and one or more expansion directions thereof. A dictionary memory for storing code character patterns, a means for obtaining a direction code image along the contour in the captured input image, a direction code including the obtained direction code image, and an expansion direction code character pattern read from the dictionary memory There is disclosed a stamped character inspection apparatus comprising means for correlating with a character pattern and inspecting whether or not the seal is normal.

Further, the present invention provides means for imprinting a plurality of characters, means for imaging an area including the imprinted characters of an object imprinted by the means, a direction code pattern for standard characters,
And a dictionary memory for storing one or a plurality of expansion direction code character patterns thereof, means for obtaining a direction code image along a contour in the captured input image, the obtained direction code image, and an expansion read from the dictionary memory. There is disclosed a stamped character inspection apparatus comprising a means for correlating with a direction code character pattern including a direction code character pattern and inspecting whether or not the seal is normal.

Further, the present invention provides a conveying line, a means for marking a plurality of characters on a conveyed object on the conveying line, a means for detecting that a stamped object has come, and imaging a marked character area.
A dictionary memory for storing a direction code character pattern for a standard character and a direction code character pattern for the expanded character, a means for capturing the captured image and obtaining a direction code image along the contour, There is disclosed a seal inspecting apparatus comprising means for correlating with a direction code character pattern including an expansion direction character pattern read from a dictionary memory and inspecting whether or not the imprint of a plurality of characters is normal.

[0011]

FIG. 1 is a diagram showing an overall system of the present invention. On the conveyer 1, a pack 2 packed with cardboard or wrapping paper (hereinafter, these are collectively referred to as a carton box) 2 is conveyed. A stamping machine 3 for stamping the carton box 2 on the conveyor 1 is provided upstream, and a discharging machine 7 for discharging a box in the case of improper stamping is provided downstream. A box detection sensor 4 and a video camera 5 are provided at an arbitrary position between them, and a stamping machine inspection device 6 is further provided. The sensor 4 detects that the carton box 2 has come in front of the
Is determined. The video camera 5 captures an image of the seal portion, and the inspection device 6 inspects the quality of the seal. The seal shall be one or more characters or figures.

FIG. 2 is a diagram showing a processing flow of the inspection device 6 when the seal is a plurality of characters. In step 21, an image captured by the video camera 5 is input. Step 22
A direction code is detected for each image including characters along the outline of the image to obtain a direction code image. This is called direction code conversion.

The direction code refers to data indicating the direction of the outline of each character in a seal portion (ie, a seal character) in an input image. Either one of various direction codes such as a four-way code of up, down, left and right, and an eight-way code obtained by adding a 45 ° diagonal direction thereto is adopted. The direction code is obtained for each pixel position (or a plurality of pixel positions). Hereinafter, each pixel position is assumed. If the contour is continuous, data indicating a direction code for each pixel position is obtained along the contour. The image thus obtained is the direction code image.

In step 23, reading is performed from a dictionary memory in which the direction code character pattern of the standard seal character and the direction code pattern of one or more of the expanded characters are stored in advance as data. In step 24, a correlation process is performed between the direction code character pattern and the expansion direction code character pattern of the standard seal characters repeatedly read from the memory and the input direction code image. Various known methods can be used for the correlation. Repeat until the highest correlation value is obtained.

It is determined in step 25 whether the obtained correlation value is equal to or greater than the specified value. If the correlation value is equal to or greater than the specified value, the character is regarded as a normal seal. If it is determined that the seal is normal, the process proceeds to step 27 at the next character. If all the characters are normal, an output indicating that the seal is normal is issued in step 28. If the value is less than the specified value, the output of the seal failure is output in step 6 using the character at that time, and the output is discharged from the conveyor 1 by the discharger 7.

The direction code will be described in detail. The direction code is data indicating the direction of the outline of the cardboard image, and one direction code is obtained for each pixel. For example, there are a four-way code and an eight-way code. A typical example of a four-way code is a four-way code that is divided into horizontal and vertical, and that is horizontal and goes to the right or left, or vertical and goes upward or downward. . That is, it is an example of the horizontal right direction, the horizontal left direction, the vertical upward direction, and the vertical downward direction. The eight directions are typically obtained by adding four oblique directions in addition to the above four directions. There are the following four directions to be newly added. 45 ° diagonally upper right direction 45 ° diagonally lower right direction 45 ° diagonally upper left direction 45 ° diagonally lower left direction

One direction code data consists of, for example, 4 bits for a 4-way code and 8 bits for an 8-way code. In the case of a four-way code, the direction code data is configured as follows. 1000 ... horizontal right direction code 0100 ... horizontal left direction code 0010 ... vertical upper direction code 0001 ... vertical lower direction code 0000 ... no direction code In eight directions, eight directions are set by setting "1" to each position of 8 bits. Is specified.

The method of calculating the direction code is determined based on what direction code the contour has in each pixel. Here, the direction code angle θ of the pixel position (i, j) for which the direction code is to be obtained is determined by the pixel value P (i, j) at this position and two adjacent pixel positions (i + 1, j), (i, j + 1). Pixel value P
Using (i + 1, j) and P (i, j + 1), it is obtained by the following equation. Here, i is the horizontal coordinate and j is the vertical coordinate.

(Equation 1) Then, it is determined as follows according to the value of θ. Where θ =
0 ° indicates an angle in the right horizontal direction, and is a counterclockwise angle. If it is an 8-way code, it is determined as follows. 337.5 ° <θ ≦ 22.5 °, horizontal right direction code 22.5 ° <θ ≦ 67.5 °, diagonal upper right 45 ° direction code 67.5 ° <θ ≦ 92.5 °, vertical Upward code: 292.5 ° <θ ≦ 337.5 °, diagonally lower left 45 ° direction code In the case of a 4-way code, it is determined as follows. 315 ° <θ ≦ 45 °, horizontal rightward code 45 ° <θ ≦ 135 °, vertical upward code 135 ° <θ ≦ 225 °, horizontal leftward code 225 ° <θ ≦ 315 °, vertical downward Direction code

FIG. 3 is a diagram showing a specific example of the inspection processing. The screen 31 in FIG. 3A is an input image from the video camera 5. “123” is shown as an example of the seal. FIG. 3A shows that the image 31A is a character image and the image 31B is an image.
Is an image showing a part of a pattern or a graphic.

By processing such an input image, a direction code converted image is obtained. FIG. 3B shows a direction code image 32A from a character “123” and a direction code image 3 of a pattern or a figure.
2B is shown.

FIG. 3C shows that the correlation processing should be performed between the dictionary character pattern 33 and the direction code images 32A and 32B obtained in FIG. 3B. As the dictionary character pattern 33, a direction code character pattern for one or more expanded characters is prepared in addition to the standard characters. Between the direction code pattern containing the inflated characters,
The entire screen 32 is scanned (for example, a raster scan), and a correlation is obtained between the images 32A and 32B one after another. For example, in the example of correlation with the standard direction character pattern “1”, the pattern of “1” in the input direction code image has the largest correlation value. The input direction code image “1” is obtained without performing “1” clipping. Therefore, FIG.
A pattern 35A at that time as shown in (d) is obtained. This pattern 35A corresponds to "1", and it is determined whether the correlation value is normal or abnormal depending on whether the correlation value is equal to or greater than a specified value.
Similarly, the standard direction character patterns "2" and "3" are obtained independently without cutting out, and "2" and "3" are obtained independently. If any one of the characters is determined to be abnormal, the subsequent correlation processing is not performed. Although the dilation patterns are stored, if there is a means for obtaining these at a high speed, only the standard direction code character patterns may be stored.

In many cases, it is sufficient for the dictionary memory to have the direction code character pattern of the standard characters, but if the dictionary memory has the expanded direction code character pattern, the accuracy will be improved. That is, the imaging direction of the video camera may be shifted or the carton box may be shifted. In these cases,
The inspection result may be erroneously determined to be abnormal even though the seal is normal. The reason for introducing an expanded character pattern is that if one or more expanded direction code character patterns are prepared in addition to the standard character direction code character pattern, such erroneous determination can be reduced. It should be noted that there may be an example in which a reduced pattern is used.

In addition to characters, it can be applied to figures. There are also examples of combinations of characters and figures.

[0024]

According to the present invention, since a character is cut out for each character and the inspection is performed by paying attention to the outline information of the character without performing the inspection, a character pattern close to which the character cannot be extracted and a pattern on the background of the character are formed. Even if there is, character inspection is possible.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of the present invention.

FIG. 2 is an image processing flowchart.

FIG. 3 is an example diagram of a determination process.

[Explanation of symbols]

 1 Conveyor 2 Carton Box 3 Stamping Machine 4 Sensor 5 Video Camera 6 Stamping Machine Inspection Equipment 7 Discharger 31 Input Video 32 Direction Code Conversion Video 33 Dictionary Video 34 Correlation Processing Video 35 Maximum Correlation Point Extraction Video

Claims (5)

[Claims] 1. A direction code image along a contour is obtained from an input image including a character to be determined as a normal character.
A character determination method for comparing the direction code image with a standard direction code character pattern to determine a character in an input image. 2. A character stamping means, means for photographing an area including a stamped character of an object stamped by this means, a dictionary memory for storing direction code character patterns for standard characters, Means for obtaining a direction code image along the contour, and means for correlating the obtained direction code image with the direction code character pattern read from the dictionary memory to check whether or not the seal is normal. Character inspection device. 3. A character stamping means, means for imaging an area including a stamped character of an object stamped by this means, a direction code pattern for a standard character, and one or a plurality of expansion direction code character patterns thereof And a means for obtaining a direction code image along the contour in the captured input image; and a direction code character pattern including the expanded direction code character pattern read from the dictionary memory. And a means for checking whether or not the seal is normal. 4. A means for imprinting a plurality of characters, means for imaging an area including a plurality of imprinted characters of an object imprinted by this means, a direction code pattern for standard characters, and one or more inflation directions thereof A dictionary memory for storing a code character pattern; a means for obtaining a direction code image along a contour in the captured input image; a direction code character including the obtained direction code image and an expanded direction code character pattern read from the dictionary memory Means for inspecting whether or not the seal is normal by correlating with the pattern, and a seal character inspection apparatus. 5. A transport line, means for imprinting a plurality of characters on a conveyed object on the transport line, means for detecting that a stamped object has come, and imaging an imprinted character area, and a direction code for standard characters A dictionary memory for storing a character pattern and a direction code character pattern of the expanded character; a means for taking in the captured image and obtaining a direction code image along the contour; a direction code image obtained from the dictionary memory and an expansion read from the dictionary memory. A means for correlating with a direction code character pattern including a direction character pattern, and for inspecting whether or not the imprint of a plurality of characters is normal.