JP3895845B2 - Image processing method and apparatus for sheet metal processing - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image processing method and apparatus for sheet metal processing, and more particularly to an image processing method and apparatus for sheet metal processing when performing a wide range of image processing.
[0002]
[Prior art]
In conventional image processing in sheet metal processing, the size of a hole processed in a sheet metal is obtained by taking an image with a camera (for example, a CCD camera), converting the imaged data into a digital signal, and processing the image using software or hardware image processing technology. It is common to find the sheath position.
[0003]
In this case, the required field of view of the camera is required to be, for example, about several mm when imaging an IC or the like, and about several hundred mm when identifying a box. For this reason, from the relationship between the resolution of the camera and the field of view, processing is performed with one camera, or the camera is moved to a necessary part and only a part is imaged.
[0004]
The captured image is converted into data for each pixel and stored in a memory, and data processing is performed later.
[0005]
On the other hand, in facsimile (FAX), an image is scanned only in one direction, and a direction orthogonal to this is sent by paper and read. In this case, at the time of reading, the data is read while being compressed in real time by the conventional run length compression.
[0006]
[Problems to be solved by the invention]
However, when taking the entire sheet metal material as an image and performing accuracy measurement, verification of processing, etc., considering the necessary resolution (for example, 0.01 mm) and the field of view (for example, 1800 mm), existing images are captured. The following problems arise from the resolution of the camera (1.3 million pixels / image, 5000 pixels / line).
[0007]
(1) Since it is necessary to divide the field of view with a plurality of cameras and synthesize data, the apparatus is expensive, the process is complicated, and adjustment is difficult.
[0008]
(2) A large memory is required to store the captured image for each pixel, resulting in an increase in the size of the apparatus.
[0009]
(3) Time is required for image processing. For example, if a material of 1500 mm × 3000 mm is read with a resolution of 0.01 mm, a large data amount of (1500 / 0.01) × (3000 / 0.01) = 4.5 × 10 ¹⁰ bits = 5.6 Gbyte is obtained.
[0010]
(4) When data is compressed as in the case of the facsimile described above, contour data in one direction can be extracted, but generally contour data in a direction orthogonal to this (paper feeding direction) cannot be extracted. The contour data of one side in the feed direction cannot be extracted.
[0011]
An object of the present invention is made by paying attention to the conventional techniques as described above, and an image processing method in sheet metal processing capable of performing image processing with a fine resolution on a sheet metal having a large outer dimension, and the like. To provide an apparatus.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, an image processing method in sheet metal processing according to the first aspect of the present invention is directed to applying illumination light from one side of a sheet metal sent in one direction, and irradiating the illumination light transmitted through the sheet metal. In an image processing method in sheet metal processing for measuring the size and position of holes processed by a camera that scans in another direction orthogonal to the direction, image data of the scan line captured by the camera is compressed in real time. And the contour of the image line perpendicular to the scanning direction is extracted from the stored image data and the image data captured later.
[0013]
Therefore, by sending the sheet metal in one direction and causing the camera to scan in the other direction orthogonal to the one direction, the illumination light transmitted through the image of the hole or the like processed in the sheet metal is captured. At this time, the necessary storage capacity is reduced by compressing and storing the image data captured by the camera in real time. The outline of the image line in one direction, which is a direction orthogonal to the scanning direction of the camera, is extracted from the stored image data and the image data captured later.
[0014]
According to a second aspect of the present invention, there is provided an image processing method for sheet metal processing, wherein the scan line is thinned out at an appropriate interval when the contour of an image line perpendicular to the scan direction is extracted in the image processing method for sheet metal processing according to the first aspect. And extracting the outline of the image line in the Y direction.
[0015]
Therefore, the outline of the image line in the direction orthogonal to the scan direction of the camera is extracted not using image data of all scan lines but using image data of scan lines thinned at appropriate intervals. .
[0016]
According to a third aspect of the present invention, there is provided an image processing apparatus for processing a sheet metal, wherein illumination light is applied from one side of the sheet metal sent in the Y direction, and the illumination light transmitted through the sheet metal is applied to a scan line in the X direction orthogonal to the Y direction. An image processing apparatus for sheet metal processing that measures the size and position of a hole that has been captured and processed by a camera that scans along the X direction, and that compresses image data of the scan line captured by the camera in real time Means, image data memory means for storing signals from the X direction processing means, image data stored in the image data memory means, and image line contours in the Y direction are extracted later from the image data Y-direction processing means.
[0017]
Therefore, by sending the sheet metal in the Y direction and causing the camera to scan in the X direction orthogonal to the Y direction, the illumination light transmitted through the image of the hole or the like processed in the sheet metal is taken in. At this time, the X direction processing means compresses and stores the image data captured by the camera in real time, thereby reducing the necessary storage capacity of the image data memory. Further, the outline of the image line in the Y direction, which is a direction orthogonal to the scanning direction of the camera, is extracted from the stored image data and the image data captured later by the Y direction processing means.
[0018]
An image processing apparatus for sheet metal processing according to a fourth aspect of the present invention is the image processing apparatus for sheet metal processing according to claim 3, wherein the Y-direction processing means thins the scan lines at an appropriate interval to obtain an outline of the image line in the Y-direction. Extracting.
[0019]
Therefore, the contour of the image line in the Y direction, which is a direction orthogonal to the scan direction of the camera, does not use image data of all scan lines, but uses image data of scan lines thinned at appropriate intervals. Extracted.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0021]
FIG. 1 shows an image processing apparatus 1 in sheet metal processing according to the present invention. In this image processing apparatus 1, for example, holes 5, 7 processed by applying illumination light L from one side (here, the lower side) of the sheet metal W fed in one direction (here, the Y direction) by the feed roller 3. A camera 9 that captures the light that has passed through is provided, and a binarization circuit 11 is connected to the camera 9.
[0022]
Referring also to FIG. 2, the binarization circuit 11 includes a threshold 13 for outputting a threshold signal for distinguishing between “bright” and “dark”, and a video signal from the camera 9 based on the signal from the threshold 13. Is converted to “bright” → “1” and “dark” → “0”.
[0023]
A black and white counter control circuit 17 is connected to the binarization circuit 11, and the black and white counter control circuit 17 is connected to the control device 23 directly or via counters 19 and 21. The black and white counter control circuit 17 and the counters 19 and 21 form an X direction processing unit 25 as X direction processing means.
[0024]
The binarization circuit 11 is connected to a black-and-white change point detection control circuit 29 directly or via a buffer 27 which is an image data memory means, and further connected to a control device 23. An adder 33 is provided for adding signals from the black / white change point detection control circuit 29 and sending the signal to a Y output suppression circuit 31 as Y output suppression means described later. The buffer 27, the black-and-white changing point detection control circuit 29, and the Y output suppression circuit 31 form a Y-direction processing unit 35 as Y-direction processing means.
[0025]
A clock control circuit 39 that receives a signal from an oscillator 37 is connected to the camera 9. The clock control circuit 39 is connected to the black / white change point detection control circuit 29 directly or via the Y output suppression circuit 31 or to the black / white counter control circuit 17. Further, the clock control circuit is connected to the control device 23 via counters 41 and 43.
[0026]
The control device 23 has a CPU 45 which is a central processing unit. The CPU 45 has a data memory 47 which is also an image data memory means, a program memory 49 which stores an image processing program, and a CRT which outputs an image processing result. The output means 51 etc. are connected.
[0027]
With the above configuration, the light transmitted through the holes 5, 7, etc. processed in the sheet metal W out of the illumination light L irradiated from below the sheet metal W is captured by the camera 9, and the hole = “bright”, the sheet metal = “ "Dark" video signal. When the binarization circuit 11 of the video signal from the camera 9 is larger than the threshold (threshold value) of the video signal, a digital signal of “bright” = data “1”, and when it is smaller, “dark” = data “0”. Convert to
[0028]
The oscillator 37 and the clock control circuit 39 generate a clock signal that is a reference of the video signal for the camera 9, and the X and Y reset signals are transmitted to the X and Y direction synchronization signals and the accompanying X direction processing unit 25 and Y direction processing unit 35. Is generated.
[0029]
The black and white counter control circuit 17 counts the number of black pixels and white pixels during X-direction scanning by the counters 19 and 21, respectively, and stores the continuous pixel length in the data memory 47 for each change. In FIG. 1, the values of Xc and Xd are recorded at the recording timings of Xa and Xb, and this is recorded in correspondence with the Y coordinate of the counter 43 indicating the feed direction position of the sheet metal W as shown in FIG. .
[0030]
In such a data format, X is regarded as an increment, and Y is regarded as an absolute coordinate. Therefore, when the processing of the sheet metal W shown in FIG. 1 is image-processed, the figure actually shown in FIG. 4 is obtained. Has been replaced. In the case of FAX, when black and white is printed based on this data, the original figure is restored as shown in FIG.
[0031]
However, according to the data, only the coordinates in the X direction, which is the scanning direction, can be obtained, so that the contour coordinates in the X direction cannot be extracted as shown in FIG. For this reason, although the circular hole 7 can be substantially recognized, the rectangular hole 5 is not recognized at the stage of vectorization or the like.
[0032]
In order to solve this problem, a buffer 27 is provided to store data for one scan, and “S” and “St ⁻¹ ” are sent to the black-and-white change point detection control circuit 29 simultaneously with the next one-line data fetch. That is, the buffer 27 performs a shift register function of the number of pixels for one scan line.
[0033]
The black-and-white change point detection control circuit 29 takes in the signals “S” and “St ⁻¹ ” described above, detects changes of 1 → 0, 0 → 1 between pixels of each Xn coordinate, and counters at this time The values 19 and 21 are stored in the data memory 47 (see FIG. 6). An image of this data as coordinates is shown in FIG.
[0034]
If the coordinates of the change points obtained above are integrated and the same point is detected in both X and Y data, the duplicated coordinates are deleted, and the contour of the original figure as shown in FIG. Everything is captured and vectorization for graphic processing becomes easy.
[0035]
Next, the shift register and the Y-direction contour extraction will be described with reference to FIGS. FIG. 9 shows a graphic image. In the figure, 1 桝 is one pixel. A hatched portion indicates a portion where the workpiece W is present, and is a dark portion. Referring to FIG. 10A, the state after the line a is taken into the buffer 27 is shown. That is, from the data of the line a fetched into the buffer 27 and the data of the scanned line b (FIG. 10B), NOT (A). AND. Since the rising edge is detected at B and the change point of the Y data is detected (FIG. 10C), the Y-direction contour can be extracted.
[0036]
Here, the transfer time of data to the data memory 47 will be described. The pixel readout time in the X direction is about 10 MHz with a clock and is 0.1 μs / pixel. In reality, it may be considered that black and white do not appear alternately at a resolution of 0.01 μm, so that the memory transfer speed of a general CPU 45 can sufficiently cope with it.
[0037]
For example, the transfer rate of the SCSI-II bus interface is 10 Mbyte / s, and when the X and Y coordinates are sent in 4 bytes each, the transferable number of times per second is 1.25 × 10 ⁶ or less. is there. Therefore, when the pixel transfer clock of the camera 9 is 10 MHz, monochrome data can be transferred alternately with a roughness of 8 pixels or more.
[0038]
Also, considering that the standard PCI bus transfer rate of current personal computers is 120 to 200 Mbyte / s, which is 10 to 20 times faster, it is possible to transfer in units of one pixel only in the X direction. I can say that. On the other hand, data to be transferred in the Y direction may be generated every pixel in the case of one side of the rectangular hole 5 shown in FIG.
[0039]
However, in the present invention, it is necessary to record data detected in both the X and Y directions, and the Y output suppression circuit 31 is provided because it is impossible with the current personal computer specifications. That is, even if there is a change point within a certain time (specified pixel readout time) after the detection of the Y-direction contour, the Y data is suppressed and ignored.
[0040]
For example, with the above-described constants, data can be transferred by suppressing the reading time of 10 to 20 pixels. Further, the contour data roughness at this time is 0.01 × 20 = 0.2 mm, which is fine enough to form a figure, and there is no problem in practicality.
[0041]
From the above results, it is possible to capture a long dimension with high resolution and compress image data in real time, so that it is possible to capture image data with a small memory, and since processing is performed by the CPU 45 in parallel after capturing one line, it is quick. Processing becomes possible.
[0042]
Further, by adding a Y-direction processing unit 35 to a point where a Y-direction contour cannot be extracted, contour data of any shape can be obtained while data compression is performed.
[0043]
In addition, this invention is not limited to the above-mentioned embodiment, It can implement in another aspect by making an appropriate change. That is, in the above-described embodiment, the case where the image data for one line is stored in the buffer 27 has been described. However, the image data may be temporarily stored in the data memory 47 instead of the buffer 27.
[0044]
In addition, a buffer 27 of a plurality of lines may be provided instead of the buffer 27 of one line. In the above-described embodiment, the processing is performed by various circuits. However, instead of this, the processing can be performed by software.
[0045]
【The invention's effect】
As described above, in the image processing method in the sheet metal working according to the invention of claim 1, the hole formed in the sheet metal by feeding the sheet metal in one direction and scanning the camera in the other direction orthogonal to the one direction. The illumination light that has passed through the image is taken in. At this time, since the necessary storage capacity can be reduced by compressing and storing the image data captured by the camera in real time, it is possible to perform image processing by finely decomposing a wide range. The outline of the image line in one direction, which is a direction orthogonal to the scan direction of the camera, is extracted from the stored image data and the image data captured later, so that the image in the direction orthogonal to the scan direction is extracted. Line processing becomes possible.
[0046]
In the image processing method in the sheet metal working according to the second aspect of the present invention, the outline of the image line in the direction orthogonal to the scan direction of the camera is not used for all the scan line image data, but is thinned out at an appropriate interval. Therefore, it is possible to perform image processing at the data transfer speed of the existing personal computer.
[0047]
The image processing apparatus in the sheet metal working according to the invention of claim 3 has transmitted the image of the hole or the like processed in the sheet metal by feeding the sheet metal in the Y direction and scanning the camera in the X direction orthogonal to the Y direction. Illumination light is captured. At this time, since the X direction processing means compresses and stores the image data captured by the camera in real time, the required storage capacity of the image data memory can be reduced. Image processing. Also, the contour of the image line in the Y direction, which is the direction orthogonal to the scan direction of the camera, is extracted from the image data previously stored by the Y direction processing means and the image data captured later. It is possible to process an image line in a direction orthogonal to the direction.
[0048]
In the image processing apparatus for sheet metal processing according to the invention of claim 4, the contour of the image line in the Y direction, which is a direction orthogonal to the scan direction of the camera, does not use the image data of all the scan lines but has an appropriate interval. Therefore, it is possible to perform image processing at a data transfer speed of a current personal computer.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an image processing apparatus in sheet metal processing according to the present invention.
FIG. 2 is a graph showing threshold levels for distinguishing between “bright” and “dark”.
FIG. 3 is an example of data stored by a black and white counter control circuit.
4 is an explanatory diagram showing an image obtained by replacing the data shown in FIG. 3 with a figure.
FIG. 5 is an explanatory diagram showing an image obtained by replacing the data shown in FIG. 3 with coordinates.
FIG. 6 is a table showing an example of memory data.
7 is an explanatory diagram illustrating an image obtained by capturing the memory data of FIG. 6 as coordinates.
8 is an explanatory diagram showing an image obtained by integrating FIGS. 5 and 7. FIG.
FIG. 9 is an explanatory diagram showing an image of a captured figure.
FIGS. 10A and 10B are diagrams illustrating captured image data, and FIG. 10C is an explanatory diagram illustrating a state in which the rise of a Y-direction image line is detected.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Image processing apparatus 5, 7 Hole 9 Camera 25 X direction processing part (X direction processing means)
27 Buffer (image data memory means)
31 Y output suppression circuit (Y output suppression means)
35 Y direction processing section (Y direction processing means)
47 Data memory (image data memory means)
W Sheet metal L Illumination light

Claims (4)

Apply the illumination light from one side of the sheet metal sent in one direction and capture the dimension and position of the hole processed by taking the illumination light transmitted through the sheet metal in the other direction orthogonal to the one direction. In the image processing method in sheet metal processing to be measured,
The image data of the scan line captured by the camera and binarized is stored for each change, and the contour of the line perpendicular to the scan direction is extracted from the stored image data and the image data captured later. An image processing method in sheet metal processing, characterized by:   2. The sheet metal processing according to claim 1, wherein when extracting an outline of an image line orthogonal to the scan direction, the image line outline in the Y direction is extracted by thinning the scan line at an appropriate interval. Image processing method. A hole formed by applying illumination light from one side of the sheet metal sent in the Y direction and capturing the illumination light transmitted through the sheet metal along a scan line in the X direction perpendicular to the Y direction. An image processing apparatus in sheet metal processing for measuring dimensions and positions,
And X-direction processing means for counting the number of each pixel of the binarized image data of the scan was captured by the camera line,
An image data memory means for storing a signal from the X-direction processing unit for each successive pixel length change,
And Y-direction processing means for extracting the contour of the Y-direction streaks from the image data captured and later stored image data in the image data memory means,
An image processing apparatus in sheet metal processing, comprising:   4. The image processing apparatus for sheet metal processing according to claim 3, wherein the Y direction processing means extracts the contour of the image line in the Y direction by thinning out the scan lines at an appropriate interval.

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