JP4923828B2 - X-ray inspection equipment - Google Patents

Description

  The present invention relates to an X-ray inspection apparatus for performing fluoroscopic inspection or CT inspection of industrial products.

In X-ray inspection equipment that performs fluoroscopic inspection of industrial products and the like, X-ray detection is performed by combining an image intensifier (hereinafter abbreviated as II) and a CCD camera so as to face the X-ray source of the X-ray generator. A vessel is arranged. Recently, an X-ray inspection apparatus using a flat panel X-ray detector is used instead of an X-ray detector composed of II and CCD cameras.
In these X-ray inspection apparatuses, a stage is disposed between an X-ray source and an X-ray detector, and an object to be measured is placed on the stage to photograph a fluoroscopic X-ray image.

  In the inspection by the X-ray inspection apparatus, the visual field is usually moved for alignment, measurement magnification adjustment, and measurement angle adjustment. In the visual field movement, a fluoroscopic X-ray moving image of the object to be measured is photographed while moving the stage, thereby searching for the inspection position of the object to be measured. When the inspection position is found, the visual field movement is stopped and the moving image is observed in that state.

  When the image of the observed inspection location is stored as final inspection data, a moving image is captured with the field of view fixed at the inspection location and stored as a still image.

  By the way, in fluoroscopic X-ray measurement, fluctuations in X-rays occur due to the principle of the X-ray generator. Therefore, a frame of a fluoroscopic X-ray image obtained by detecting the fluctuating X-rays with an X-ray detector. The image data (each image data forming a moving image) includes flicker noise. Therefore, flicker noise is also observed in the moving image display in which the frame images of the respective fluoroscopic X-ray images are sequentially displayed.

  In order to reduce this flickering noise, conventionally, a plurality of frame images forming a moving image are accumulated in an image buffer memory, and the averaged processing of the accumulated image data and the latest frame image data (average of each pixel) Display). The averaged image data subjected to the averaging process is flattened by averaging noise components that cause flickering. However, on the other hand, the display update speed of the frame image data during moving image display decreases.

For example, as shown in FIG. 8A, when the frame image data 1 to 4 are sequentially created based on the imaging signal from the X-ray detector, the two frames of frame image data are averaged. Then, as shown in FIG. 8B, two frames of frame image data are accumulated in the image buffer memory, and one averaged image data is created by performing these averaging processing operations, and this is displayed. Repeat the process. In this case, since the averaged image data is updated at a time interval at which two frame image data is created, the update speed is reduced. If averaging with more frame image data is performed, the update speed will be reduced accordingly. As a result, the averaged image data cannot be displayed continuously, and the frame-by-frame moving image display is obtained. End up.
This becomes conspicuous when a flat panel X-ray detector is used as the X-ray detector. That is, compared with an X-ray detector using II and a CCD camera, a flat panel X-ray detector originally has a small frame rate, and therefore it is apt to be frame-by-frame display.

In addition to displaying moving images on the screen of a display device, when storing inspection results as high-definition still images, moving images taken for a certain period of time (usually at least about a few seconds) (ie, a considerable number of frame images) The averaged image data obtained as a result is stored as still image data.
By performing the moving image averaging process in this way, a fine still image can be obtained. However, as the high-definition still image is obtained, a display waiting time is required.

  As another method for improving the decrease in update speed due to the averaging process, recursive filter processing is also performed (see, for example, Patent Document 1). In the recursive filter processing, as shown in FIG. 8C, the latest frame image data is weighted with the previous image data (the previous image data itself is further subjected to the recursive filter processing of the previous image data). This is an image processing method that reduces flicker noise by adding and correcting. As a result, the update speed comparable to that of the moving image display by the original frame image data can be achieved, and the reduction in the update speed can be improved by the recursive filter processing.

In fluoroscopic X-ray measurement, it is preferable to increase the number of pixels as much as possible from the viewpoint of improving image quality. However, as the number of pixels increases, the load of moving image display increases, and the update speed of image data increases the number of pixels. Depending on the speed.
In order to improve the update speed of moving image display, a binning process for creating image data is performed by regarding a plurality of adjacent pixels as one pixel to increase the update speed (for example, Patent Documents). 2).
JP 2000-316835 A Japanese Patent Laid-Open No. 2001-231777

As described above, flicker noise can be eliminated by performing averaging processing on the frame image data, but a problem of a decrease in update speed newly occurs.
The recursive filter processing can solve the problem of flickering noise and a decrease in update speed. However, when the fluoroscopic X-ray image of the object to be measured is moved by the visual field movement, the afterimage of the object to be measured is displayed on the display screen. Will remain and blurring of the image will occur. For a while (several seconds or more) after the object to be measured stops, the blurring of the image continues, and during this time, there is a waiting time.

In response to a decrease in the update speed, the moving image update speed can be improved by executing a binning process. However, since the number of pixels is substantially reduced by the binning process, the resolution is lowered and the image quality is deteriorated. Also, to switch from the mode that executes the binning process (execution mode) to the mode that does not execute the binning process (release mode), or vice versa, depending on hardware restrictions, Switching time of about several seconds is required.
Thus, improvement in image quality and followability with respect to visual field movement are contradictory problems, and it has been difficult to solve these two problems at the same time.

  Accordingly, the present invention provides an easy-to-use X-ray inspection apparatus that solves two conflicting problems, one is an improvement in image quality and the other is an improvement in followability with respect to visual field movement. With the goal.

  In addition, when performing fluoroscopic inspection and CT inspection, the normal work process is as described above, the visual field moving process for searching the inspection location, the observation process for observing the moving image on the screen for the inspection location, and as necessary In response, a photographing process for photographing a high-definition still image is performed. Accordingly, an object of the present invention is to provide an X-ray inspection apparatus that is easy to use from the viewpoints of display image quality and display followability, corresponding to these steps.

First, an invention which is a premise of the present invention described later will be described. In the premise invention, switching between moving image display with priority on image quality or moving image display with priority on follow-up to visual field movement is switched according to the situation.
In other words, the X-ray inspection apparatus as a premise of the present invention is an X-ray comprising an X-ray generator that irradiates a measurement object with fluoroscopic X-rays and an X-ray detector that images a fluoroscopic X-ray image of the measurement object A frame image data creation unit that repeatedly creates frame image data of a fluoroscopic X-ray image frame by frame based on a measurement optical system, a video signal photographed by an X-ray detector, and an image buffer memory for creating fine image data Accumulated image data, a fine image data creating unit that creates fine image data using the accumulated image data and the latest fluoroscopic X-ray frame image data, a display device that displays the image data, and an object to be measured A visual field adjustment unit that adjusts the positional relationship between the X-ray measurement optical system and the measurement visual field for the object to be measured, a visual field fluctuation determination unit that determines whether the measurement visual field fluctuates, and a determination that the visual field is fluctuating In case of Display data, when the determined field of view is constant so that and an image mode switching unit for displaying a fine image data.

Here, any X-ray detector may be used as long as it can output a fluoroscopic X-ray image as a video signal, but in particular, a flat panel X-ray detector having a relatively low frame rate may be used. The effectiveness of the present invention becomes remarkable.
The “image data for creating fine image data” stored in the image buffer memory is image data used for the process of removing flicker noise, and is image data having the same field of view as the latest image data of a fluoroscopic X-ray image. It is desirable to be. Specifically, it is preferable to store frame image data captured in the past with the same field of view as the latest frame image data or fine image data created last time as “image data used for fine image data creation”.
In addition, since the visual field adjustment unit can adjust the visual field by changing the relative positional relationship between the object to be measured and the X-ray measurement optical system, the object to be measured, the X-ray generator, the X-ray detector Any mechanism that moves at least one of them may be used.
Further, the visual field variation determination unit may determine the visual field variation based on a control signal from the visual field adjustment unit that is sent when the visual field variation is generated, or a sensor that can detect the variation of the visual field adjustment unit ( For example, the visual field variation may be determined using a stage position sensor.

According to the present invention, the frame image data creation unit sequentially creates frame image data of fluoroscopic X-ray images one by one based on the video signal from the X-ray detector. Each frame image data includes flicker noise. The fine image data creation unit accumulates image data for fine image data creation in the image buffer memory, and creates the latest fine image data using the accumulated image data and the latest frame image data of the fluoroscopic X-ray image. To do. The fine image data is image data from which flicker noise has disappeared due to averaging or the like. On the other hand, the measurement visual field for the object to be measured is changed by the visual field adjustment unit, and the visual field fluctuation determination unit determines the presence or absence of the measurement visual field fluctuation.
The image mode switching unit displays the frame image data when it is determined that the visual field is changing. In other words, it is sufficient for the observer to have the minimum image quality to identify the observation location while the field of view is moving. Since it is necessary to improve, the frame image data created by the frame image data creation unit is displayed.
The image mode switching unit displays fine image data when it is determined that the visual field has not changed. That is, in the state where the visual field variation is finished and fixed, visual field followability is unnecessary, and thus image data with good image quality is displayed.
In this way, display that emphasizes followability (frame image display) or display that emphasizes image quality (fine image mode) is performed depending on whether the field of view is changing or the field of view is fixed.

  According to the present invention, since a display with good image quality and a display with good follow-up are automatically switched according to the situation, the X-ray inspection apparatus is easy to use.

In the above invention, the fine image data creating unit executes recursive filter processing or averaging processing using the image data for fine image creation stored in the image buffer memory and the latest frame image data of the fluoroscopic X-ray image. It may be.

In here, when the recursive filtering to use a definition image data previously created as image data for creating definition image, when the averaging processing of the last of a plurality of frames frame image data creation unit creates frame images The data is preferably used as fine image data.
According to this, fine image data with the same visual field and less image blur can be obtained unless the previous fine image data and the latest frame image data are changed by the visual field adjustment unit.

At this time, the fine image data creation unit may discard the fine image creation image data stored in the image buffer memory when the visual field variation determination unit determines that the measurement visual field has changed. Good.
According to this, since it is possible to avoid creating fine image data based on image data having a measurement field of view different from that of the latest frame image data, it is possible to create a fine image without image blur.

Further, in the above invention, the frame image data creation unit executes the binning process to create the frame image data when the visual field variation determination unit determines that the measurement visual field has changed, and the measurement visual field has changed. If no determination is made, the frame image data may be created without executing the binning process.
According to this, during visual field fluctuation, the followability of the image can be further improved by binning processing, and after the visual field is fixed, a fine image can be created with normal frame image data.

Further , the X-ray inspection apparatus of the present invention , which is made by further applying the above-mentioned presupposed invention, includes an X-ray generator that irradiates the object to be measured with X-rays for fluoroscopy and a fluoroscopic X-ray image of the object to be measured X-ray measuring optical system comprising an X-ray detector for photographing the image and a binarizing process based on the video signal imaged by the X-ray detector, or canceling the binning process to obtain a fluoroscopic X-ray image A frame image data creation unit that repeatedly creates frame image data for each frame, and past image data created by performing recursive filter processing on the frame image data created by executing binning processing, or binning processing is executed Any one of the at least one past frame image data created in this way is stored in the image buffer memory as image data for creating fine image data, and the stored fine image data is stored in the image buffer memory. A fine image data creation unit that creates fine image data that has been subjected to recursive filter processing or averaging processing using image data for creation and frame image data of the latest fluoroscopic X-ray image created by executing binning processing; Either the past image data created by performing the recursive filter processing on the frame image data created by canceling the binning process, or at least one past frame image data created by canceling the binning process Recursive filter processing using still image data creation image data stored in the image buffer memory and using the stored still image data creation image data and the latest fluoroscopic X-ray frame image data created by canceling the binning process Or a still image data creation unit for creating averaged still image data, and image data A visual field adjustment unit that adjusts the positional relationship between the object to be measured and the X-ray measurement optical system to change the measurement field of view of the object to be measured, and a field variation determination that determines whether or not the measurement field of view varies A still image creation instruction unit that generates a still image creation instruction signal, and a binning process control unit that switches presence / absence of binning processing to the frame image data creation unit based on the presence or absence of the still image creation instruction signal The frame image data is displayed when it is determined that there is no instruction signal for creating a still image and the field of view is changing, and the fine image is displayed when it is determined that there is no instruction signal for a still image and the field of view is constant. An image mode switching unit for displaying data and displaying still image data when there is a still image instruction signal is provided.

  Here, the still image creation instruction unit generates a still image creation instruction signal. The instruction signal is generated when there is an instruction operation for creating a still image by a well-known input device of the operator of the apparatus, or when the field of view is fixed at an inspection position set in advance by an automatic sequence. be able to.

According to the present invention, the visual field moving step for finding the inspection location, the observation step for observing the moving image on the screen for the inspection location, and the imaging step for capturing a high-definition still image of the observed inspection location are displayed separately. The image quality and followability of the image are switched.
That is, when the still image creation instruction unit does not generate a still image creation instruction signal, the binning process control unit controls the frame image data creation unit to create the frame image data that has been subjected to the binning process. When the still image creation instruction unit generates a still image creation instruction signal, the binning process control unit controls the frame image data creation unit to create the frame image data for which the binning process has been canceled. The visual field variation determination unit determines the variation of the measurement visual field, and determines whether the visual field is moving or the visual field is being fixed.
When it is determined that a still image creation instruction signal is not generated and the field of view is changing (during the field of view movement process), the frame image data (also referred to as coarse image data) subjected to the binning process is executed. Is displayed. This frame image data includes flicker noise and the image quality is not good, but it can be displayed at high speed, so that it is possible to display with good follow-up even during visual field movement.
Further, when it is determined that a still image instruction signal is not generated and the field of view is constant (observation step), fine image data created by the fine image data creation unit, that is, binning processing is executed. Fine image data, which is image data obtained by performing recursive filter processing or averaging processing on the frame image data, is displayed. This fine image data is improved in flicker noise than the coarse image data, but the followability is deteriorated. However, since the field of view is fixed, followability is not a problem.
In addition, when a still image instruction signal is generated (photographing process), recursive filter processing or averaging processing is performed on still image data created by the still image creation unit, that is, frame image data for which binning processing has been canceled. Still image data (also referred to as high-definition image data) that is image data is displayed. The high-definition image data is more suitable than the image data of the inspection result because the image quality is further improved as compared with the coarse image data and the fine image data.

  In addition, when performing the visual field movement process, the observation process, and the photographing process in order, the operator waits for the transition from the visual field movement process to the observation process compared to the waiting time when the observation process is completed and the photographing process is performed. Time is something you care about. When the binning process is executed, the waiting time required for switching to cancel the binning process from the execution state of the binning process may be anxious. In the present invention, the process for canceling the binning process is changed from the observation process to the imaging process. Since the state where the binning process is executed is maintained between the visual field moving step and the observation step, it is possible to prevent the operator from worrying much about the waiting time.

In the above invention, the fine image data creation unit discards the fine image creation image data stored in the image buffer memory when the visual field variation determination unit determines that the measurement visual field is fluctuating. It may be.
According to this, since it is possible to avoid creating fine image data based on image data with different measurement fields of view, it is possible to create a fine image without image blurring.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments described below, and it goes without saying that various aspects are included without departing from the spirit of the present invention.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of an X-ray inspection apparatus according to an embodiment of the present invention. The X-ray inspection apparatus 1 includes an X-ray measurement optical system 13 including an X-ray generator 11 and an X-ray detector 12, a visual field adjustment mechanism 14 that adjusts a measurement visual field of an object to be measured, and an overall apparatus. And a control system 15 that performs control.

The control system 15 is configured by a general-purpose computer device. The hardware of the control system 15 is further described. The CPU 21, an input device 22 such as a keyboard and a mouse, a display device 23 such as a liquid crystal panel, and an image for storing image data. The buffer memory 24 is used.
Further, the functions processed by the CPU 21 will be described in block form. The frame image data creation unit 31, the fine image data creation unit 32, the visual field adjustment control unit 33, the visual field variation determination unit 34, the image mode switching unit 35, and the stored image data erasure Divided into parts 36.

  The X-ray generator 11 constituting the X-ray measurement optical system 13 includes an X-ray tube for fluoroscopic X-ray irradiation. The X-ray detector 12 uses a flat panel X-ray detector composed of an X-ray conversion layer and a substrate with a TFT circuit, and forms a fluoroscopic X-ray image photographed by the X-ray conversion layer in the TFT circuit. Each pixel electrode read out is read out and output as a video signal.

  The visual field adjustment mechanism 14 adjusts the inspection position by moving the stage 16 on which the object to be measured S is placed, and the two-dimensional XY direction, which is the stage surface direction, and makes the stage 16 perpendicular to the stage surface. The three-dimensional drive mechanism 17 that adjusts the measurement magnification by moving in the Z direction, which is the direction, is controlled by the visual field adjustment control unit 33. The movement of the stage 16 adjusts the field of view of the fluoroscopic X-ray with respect to the object S to be measured. That is, the visual field adjustment mechanism 14 and the visual field adjustment control unit 33 function as a visual field adjustment unit.

Each functional block of the CPU 21 will be described. Frame image data generating unit 31, based on the video signals fluoroscopic X-ray image sent from the X-ray detector 12 performs one after another digital image processing, and controls to create a frame image data D _n. Specifically, to create a frame image data D _n, for example, 8 frames / sec. Note that each generated frame image D _n includes flicker noise.
In addition, the frame image data creation unit 31 regards a plurality of adjacent pixels (for example, 2 × 2 pixels) as one pixel in order to improve processing speed when performing digital imaging processing of a video signal. Binning processing can be performed. Whether or not to execute the binning process is determined based on a determination result by the visual field variation determination unit 34 described later.

Definition image data creation unit 32, each time frame image data creation unit 31 creates the latest frame image data D _n of the perspective X-ray image, created when the previous definition image creation, stored in the image buffer memory 24 The processed fine image data C _n-1 is read, and the latest frame image data D _n is added to the fine image data C _n-1 at a preset ratio, and the obtained image data is updated to the latest Processing (recursive filter processing) for storing the fine image data C _n in the image buffer memory 24 is performed. Thereby, the fine image data C _n is updated every time the latest frame image data D _n is created. Incidentally, when creating the first definition image data, since the image buffer memory 24 the previous definition image data not stored, is treated as a blank frame image D ₀ is formally accumulation. During the transition period, flicker noise remains for a while, but clear and fine image data is gradually formed.

  The visual field adjustment control unit 33 controls the three-dimensional drive mechanism 17 to move the stage 16 to a desired position when the operator gives an instruction to move the stage 16 in the XY direction or the Z direction by the input device 22. Control to move.

  The visual field variation determination unit 34 performs processing for determining the presence or absence of visual field variation based on the drive signal sent from the visual field adjustment control unit 33 to the three-dimensional drive mechanism 17. That is, when the drive signal is sent, the stage 16 moves, so it is determined that the field of view is changing, and when the drive signal is not sent, it is determined that the field of view is being fixed.

Based on the determination result of the visual field variation determination unit 34, the image mode switching unit 35 displays the frame image data D _n on the screen of the display device 23 during the visual field variation, and displays the fine image data C _n while the visual field is fixed. Take control.
The accumulated image data erasure unit 36 performs control to erase the image data accumulated in the image buffer memory 24 during the visual field variation based on the determination result of the visual field variation determination unit 34.

Next, the measurement operation (display processing operation) by the X-ray inspection apparatus 1 will be described. FIG. 2 is a flowchart showing the measurement operation.
The measurement object S is placed on the stage 16 and measurement is started. By monitoring the control signal of the stage 16, it is determined whether the stage 16 is moving or stopped (S101).

When the decision stage 16 is stopped, and the binning processing function to the OFF state (S102), to create a frame image data _{D n} (S103).
Subsequently, the recursive filter is turned on (S104), image data for fine image creation (fine image data C _n-1 created last time) and latest frame image data D _n stored in the image buffer memory 24, and Thus, the fine image data C _n is newly created and stored (updated) in the image buffer memory 24 (S105).
Then, to display the latest definition image data _{C n} created on the screen of the display device 23 (S106).
Thereafter, the process returns to S101 and the process is repeated.

On the other hand, when it is determined in S101 that the stage 16 is moving, in order to avoid the occurrence of image blurring, the image data for fine image creation stored in the image buffer memory 24 (the fine image data C _n created previously) is stored. _-1 ) is deleted (S107). That is, for data processing, it is assumed that blank fine image data C ₀ is accumulated.
Subsequently, in order to execute processing that prioritizes followability, the binning processing function is turned on (S108), and frame image data D′ _n generated by executing binning processing is generated (S109).
Subsequently, the recursive filter is turned off (S110), and the fine image data C ′ _n is not used and is not created. The fine image data C ′ _n is not accumulated in the image buffer memory 24 (the fine fine data C ₀ is assumed to be accumulated).
Then, the latest frame image data D′ _n is displayed on the screen of the display device (S111).
Thereafter, the process returns to S101 and the process is repeated.

  FIG. 3 shows the frame image data for each number of times when the display process described in FIG. 2 is repeatedly executed after the stage 16 is stopped, the fine image data stored in the image buffer memory, and the screen of the display device 23. FIG. 4 is an example of an image displayed on the screen of the display device 23. In this example, the stage is moved before the seventh display process, and the stage is stopped before the tenth display process.

  Here, it is necessary to repeat the recursive filter processing at least four times until the image in which the flicker noise disappears is displayed by the recursive filter processing. Until then, temporary fine image data including the flicker noise is displayed. After that, it is assumed that stable fine image data is displayed.

When the measurement operation (display process) is started by the operator, the first frame image data D ₁ is created by the first display process, and the fine image data C ₀ (blank paper fine image data) is stored in the image buffer memory 24. the image data C ₁ obtained by the recursive filtering process is accumulated by the frame image data D ₁ of the immediately preceding and. However, since the image data C ₁ is containing the flicker noise is a definition image data temporary. On the display device 23, definition image data C ₁ of the provisional appears.
Similarly, frame image data D ₂ (D ₃ ) is created by the display process of the second display process (third display process), and temporary fine image data C ₂ (C ₃ ) is stored in the image buffer memory. And displayed on the display device 23.

The 4th display processing, the frame image data D ₄ is created. When executing the recursive filtering by the definition image data C ₃ stored in the image buffer memory 24, since the repetition of the recursive filtering required number has been made, definition image data C ₄ noiseless flickering are obtained. This is stored in the image buffer memory 24 and the latest fine image data C ₄ is displayed on the screen of the display device 23. FIG. 4A shows an example of an image at this time, and a fine image without flickering noise is displayed.
Thereafter, in the fifth display process (sixth display process), the fine image data C ₅ (C ₆ ) is updated with the frame image data D ₅ (D ₆ ).

If the stage 16 is moved before the seventh display process, the binning process is turned on in order to improve the followability to the fluctuation, and the frame image data D ′ ₇ is generated by the binning process. At this time, the fine image data C ₆ stored in the image buffer memory 24 is erased, and the blank fine image data C ₀ is formally stored. Further, the frame image data D ′ ₇ is displayed on the screen of the display device 23. FIG. 4B shows an example of an image at this time, and a coarse image including flicker noise and binning processing is displayed. Since the stage is moving, the image quality is sufficient, and the fluoroscopic X-ray image of the object S can be displayed with good followability.
In the eighth display process (the ninth display process), frame image data D ′ ₈ (D ′ ₉ ) is created, and the image displayed on the screen of the display device is updated.

Before 10th display processing, the stage movement is stopped, binning becomes OFF state, normal frame image data D ₁₀ of being created. Formal definition image data C _{0 (blank} definition image data) and the immediately preceding frame image data D ₁₀ and definition image data C ₁₀ obtained by recursive filtering by of the image buffer memory 24 is accumulated. However, since the image data C ₁₀ is containing the flicker noise is a definition image data temporary. On the display device 23, definition image data C ₁₀ provisional appears.
Similarly, frame image data D ₁₁ (D ₁₂ ) is created by the eleventh display process (twelfth display process), and temporary fine image data C ₁₁ (C ₁₂ ) is stored in the image buffer memory 24. At the same time, it is displayed on the display device 23.
In addition, the 13th display process is created frame image data D _13, since the repetition of recursive filtering required number has been made, definition image data C ₁₃ noiseless flickering are obtained. FIG. 4C shows an image example at this time, and a fine image without flickering noise is displayed.

  By the above processing operation, while the visual field fluctuates due to the stage movement, it is possible to perform moving image display with good followability to the fluctuation, and after the stage is stopped and the visual field is fixed, the recursive filter processing is performed. Since a fine image can be displayed, an optimal display mode can be realized according to the situation, and an easy-to-use X-ray inspection apparatus can be obtained.

(Embodiment 2)
In the X-ray inspection apparatus 1 described above, the recursive filter process is performed when the fine image data is created. Instead, the fine image data may be created by performing an averaging process. Good.

  FIG. 5 is a block diagram illustrating the configuration of the X-ray inspection apparatus 2 that creates fine image data by averaging processing. In the figure, the same components as those in FIG.

The X-ray inspection apparatus 2 that executes the averaging process executes the averaging process and creates fine image data instead of the fine image data creating unit 32 that executes the recursive filter process and creates the fine image data. An image data creation unit 37 is provided.
The fine image data creation unit 37 is stored in the image buffer memory 24 together with the latest image data D _n every time the frame image data creation unit 31 creates the latest frame image data D _n of a fluoroscopic X-ray image. Averaging processing (determining an average value for each pixel) using frame image data D _n-4 , D _n-3 , D _n-2 , D _n-1 (“image data used for fine image data creation”) , create a new definition image data C _n, latest fine image data C _n created, with the latest image data D _n, performs control of storing the image buffer memory 24. At this time, when frame image data exceeding the memory capacity of the image buffer memory 24 is accumulated, the old frame image data is discarded. Further, as immediately after the stage stops, the image buffer memory 24, when the necessary number of frame image data is not stored, for example, as formally is frame image data D ₀ in the blank are accumulated, formally An averaging process may be executed.
This D _n-1 is the frame image data created immediately before (previous), D _n-2 is one before D _n-1 , D _n-3 is one before D _n-2 , D _{n -4} is frame image data created immediately before Dn _-3 . For convenience, the latest image data _{D n,} the frame image of the stored four frames data _{D n-4, D n-} 3, is performed averaging processing of the _{D n-2, D n-} 1 As the number of stored frame image data increases, flicker noise can be reduced. However, since such a memory capacity is required, an appropriate memory capacity is set according to the required image quality.

  FIG. 6 is a flowchart showing a measurement operation by the X-ray inspection apparatus 2. The difference from FIG. 2 is S204 (S104 in FIG. 2) and S210 (S110 in FIG. 2). In short, the recursive filter process is replaced with the averaging process, and the process flow is the same.

7, similarly to FIG. 3, frame image data for each number of times and fine image data stored in the image buffer memory 24 when the display processing of the flowchart shown in FIG. 6 is repeatedly executed after the stage 16 is stopped. FIG. 4 is a diagram illustrating an example of image data displayed on the screen of the display device 23.
In the averaging processing, as the image data stored in the image buffer memory 24, together with the definition image data _{C n,} the last frame image data of a plurality of frames _{D n-4, D n-} 3, D n-2, D n- ₃ is basically the same as FIG. 3 except that ₁ is included.
As described above, in the case of the averaging process, as in the case of the recursive filter process, while the field of view is fluctuating due to the stage movement, it is possible to display a moving image with good followability to the fluctuation and the stage is stopped. After the state becomes fixed and the field of view is fixed, it is possible to display a fine image by recursive filter processing, so that an optimal display mode can be realized according to the situation, and an easy-to-use X-ray inspection apparatus can be obtained. it can.

In the above description of the two embodiments, the flat panel X-ray detector is used, but the present invention can also be applied to the case where an X-ray detector that combines II and a CCD camera is used. Moreover, although the X-ray fluoroscopic apparatus has been described in the above embodiment, the present invention can also be applied to an X-ray CT apparatus.
(Embodiment 3)

  In the embodiment described above, the usability between the field of view movement (field movement process) and the field fixation (observation process) is improved. However, in the embodiment described below, further observation points are observed. Usability is improved, including the shooting process for shooting high-definition still images.

FIG. 9 is a block diagram illustrating the configuration of an X-ray inspection apparatus 3 that is another embodiment of the present invention. In the figure, the same components as those in FIGS. 1 and 5 are denoted by the same reference numerals, and a part of the description is omitted.
In this X-ray inspection apparatus 3, the X-ray measurement optical system 13 and the visual field adjustment mechanism 14 are the same as those shown in FIGS.

The control system 15 is configured by a general-purpose computer device. The hardware of the control system 15 is further described. The CPU 21, an input device 22 such as a keyboard and a mouse, a display device 23 such as a liquid crystal panel, and an image for storing image data. The buffer memory 24 is used.
The functions processed by the CPU 21 will be described as a block. The frame image data creation unit 41, the fine image data creation unit 42, the still image data creation unit 43, the still image creation instruction unit 44, the binning processing control unit 45, and the visual field adjustment control unit. 33, a visual field variation determination unit 34, an image mode switching unit 46, and an accumulated image data erasing unit 36.

Each functional block of the CPU 21 will be described. The frame image data creation unit 41 performs digital imaging processing one after another based on the video signal of the fluoroscopic X-ray image sent from the X-ray detector 12, and the frame image data D ′ _n , which has undergone binning processing, or performs control to create a frame image data D _n releasing the binning process. That is, when releasing the binning process is to create a frame image data D _n, for example, 8 frames / sec, when executing the binning process creates a rough frame image data D _'n faster than it. Note that the generated frame images D _n and D ′ _n include flicker noise. Switching whether or not to execute the binning process is performed based on a control signal from a binning process control unit 45 described later.

The fine image data creation unit 42 creates the latest frame image data D ′ _n of the fluoroscopic X-ray image while the frame image data creation unit 41 executes the binning process, together with the latest image data D ′ _n , Average using frame image data D ′ _n−4 , D ′ _n−3 , D ′ _n−2 , D ′ _n−1 (“fine image data for creating fine image data”) stored in the image buffer memory 24 performs processing (an average value for each pixel), 'create a _n, latest definition image data C created' new definition image data C _n, the with the latest image data D _'n, in the image buffer memory 24 Perform accumulation control. At this time, when frame image data exceeding the memory capacity of the image buffer memory 24 is accumulated, the old frame image data is discarded. Further, when the required number of frame image data is not stored in the image buffer memory 24 immediately after the stage is stopped, it is assumed that, for example, the blank frame image data D ′ ₀ is stored in a formal manner. Alternatively, the averaging process may be executed.
Note that D ′ _n−1 is frame image data created immediately before (previous time), D ′ _n−2 is one before D ′ _n−1 , and D ′ _n−3 is D ′ _n−2 . The previous image D ′ _n−4 is frame image data created immediately before D ′ _n−3 . Here, for convenience, the averaging process of the latest image data D ′ _n and the accumulated four-frame image data D ′ _n−4 , D ′ _n−3 , D ′ _n−2 , and D ′ _n−1. However, flicker noise can be reduced as the number of accumulated frame image data is increased. However, since such a memory capacity is required, an appropriate memory capacity is set according to the required image quality.
Thereby, the fine image data C ′ _n is updated every time the latest frame image data D ′ _n is created. When fine image data is created for the first time, since the previous fine image data is not accumulated in the image buffer memory 24, processing is performed assuming that a blank frame image D' ₀ is formally accumulated. During the transition period, flicker noise remains for a while, but clear and fine image data is gradually formed.

Still image data generating unit 43, in a state where the frame image data generating unit 41 releases the binning process every time to create the latest frame image data D _n of the perspective X-ray image, with the latest image data D _n, the image An averaging process is performed using the frame image data D _n−4 , D _n−3 , D _n−2 , and D _n−1 (“image data for creating still image data”) stored in the buffer memory 24, create a new still image data C _n, the latest definition image data C _n created, with the latest image data D _n, performs control of storing the image buffer memory 24. At this time, when frame image data exceeding the memory capacity of the image buffer memory 24 is accumulated, the old frame image data is discarded. Further, as immediately after the stage stops, the image buffer memory 24, when the necessary number of frame image data is not stored, for example, as formally is frame image data D ₀ in the blank are accumulated, formally An averaging process may be executed.
This D _n-1 is the frame image data created immediately before (previous), D _n-2 is one before D _n-1 , D _n-3 is one before D _n-2 , D _{n -4} is frame image data created immediately before Dn _-3 . For convenience, the latest image data _{D n,} the frame image of the stored four frames data _{D n-4, D n-} 3, is performed averaging processing of the _{D n-2, D n-} 1 As the number of stored frame image data increases, flicker noise can be reduced. However, since such a memory capacity is required, an appropriate memory capacity is set according to the required image quality.
As a result, the still image data C _n is updated every time the frame image data D _n for which the latest binning processing is canceled is created. The still image data C _n has an improved image quality as compared with the fine image data C ′ _n , but requires time for updating. Incidentally, when creating the first still image data, since the image buffer memory 24 the previous still image data not stored, is treated as a blank frame image D ₀ is formally accumulation. During the transition period, flickering noise remains for a while, but high-definition still image data is gradually formed.
Execution of the still image data creation unit 43 is started by generation of an instruction signal from a still image creation instruction unit 44 described below.

  The still image creation instruction unit 44 performs control to generate a still image creation instruction signal. More specifically, when an operator observes an inspection location and tries to save a still image, the operator operates the input device 22 to detect this and generate an instruction signal for creating a still image. It is like that. In this case, although it depends on detection of manual operation, it may be automated by creating an automatic sequence program. For example, when the shape of the inspection object is constant and the inspection location is always at the same position, the coordinate position to be observed is automatically stored by using a so-called known teaching function. After moving the position and automatically observing (for example, pattern comparison with a standard image stored in advance) at the corresponding position and confirming it, control to generate a still image creation instruction signal may be performed. Good. A still image creation instruction signal is sent to a binning processing control unit 45 described below.

  The binning processing control unit 45 monitors whether or not an instruction signal for generating a still image is generated. If no instruction signal is generated, the binning processing control unit 45 generates a frame image while performing a binning process on the frame image data generating unit 41. When an instruction signal is generated, the frame image data creation unit 41 is controlled to cancel the binning process and create a frame image.

The visual field adjustment control unit 33 and the visual field fluctuation determination unit 34 are the same as those described with reference to FIGS. 1 and 5, and the image mode switching unit 35 generates an instruction signal by the still image creation instruction unit 44, and the visual field Based on the determination result of the fluctuation determination unit 34, control for switching the display image is performed.
Specifically, when it is determined that there is no still image creation instruction signal and the field of view is changing, the frame image data (coarse image data) that has been subjected to the latest binning process is displayed, and the still image instruction signal is displayed. When it is determined that there is no image and the field of view is constant, fine image data is displayed, and when there is a still image instruction signal, still image data (high-definition image data) is displayed.

  The accumulated image data erasure unit 36 performs control to erase the image data accumulated in the image buffer memory 24 during the visual field variation based on the determination result of the visual field variation determination unit 34.

Next, the measurement operation (display processing operation) by the X-ray inspection apparatus 3 will be described. FIG. 10 is a flowchart showing the measurement operation.
When the measurement object S is placed on the stage 16 and measurement is started, display processing is started. The moving image of the image data can be displayed on the display device 23, and when the image data is sent, the screen is sequentially displayed (S301).

At the start of measurement, no still image creation instruction signal is generated, so a frame image data image on which binning processing has been executed is created (S302). Therefore, the frame image data created at this time is coarse image data including flickering noise. Subsequently, the stage 16 is monitored to determine whether the stage 16 is moving or stopped. (S303). When the stage is moving, the process proceeds to S304, and when the stage is stopped, the process proceeds to S308.

When it is determined that the stage 16 is in the moving state, the image data stored in the memory 24 is deleted (S304), and frame image data subjected to binning processing is created (S305).
Subsequently, the averaging process function is turned off so that the averaging process is not performed (S306), the latest frame image data created is displayed on the display device 23 (S307), and the process returns to S303 again. Return and repeat the same process. The displayed image contains flickering noise, but can be displayed at high speed and has excellent followability.

When it is determined that the stage 16 is in the stopped state, a frame image data image for which the latest binning processing has been executed is created (S308). Therefore, the created frame image data is coarse image data.
Subsequently, averaging processing is performed by turning on the averaging processing function (S309), and the latest image data for fine image creation stored in the image buffer memory 24 and the latest frame image data are used to update the latest processing. Are generated (S310) and displayed on the display device 23 (S311).
The displayed image is a fine image from which flicker noise has been removed by the averaging process. Since the image at this time takes time required for the averaging process, the display speed is slightly slow, but it is not a problem because it is stopped.

  Subsequently, it is determined whether an instruction signal for generating a still image has been generated (S312). If no instruction signal has been generated, the process returns to S303 and the same processing is repeated, and if an instruction signal has been generated, the process proceeds to S313.

If it is determined in S312 that a still image creation instruction signal has been generated, the binning process is canceled (OFF state) (S313). Thereby, the frame image data from which the binning process is canceled is created thereafter.
Subsequently, an averaging process is performed using the frame image data for which the binning process has been canceled (S314), and still image data is created (S315). Thereafter, the averaging process and still image data creation are repeated until the set number of times is reached (S316), and when the set number of times is reached, the still image is saved and stored in the memory (S317).

  FIG. 11 illustrates an example of frame image data for each number of times when the display process described with reference to FIG. 10 is executed, image data stored in the image buffer memory, and image data displayed on the screen of the display device 23. FIG. 12 is an example of an image displayed on the screen of the display device 23. In this example, it is assumed that the stage is moved from the first time to the third time, the stage is stopped and observed from the fourth time to the eighth time, and an input operation of still image shooting is performed before the ninth time. Yes. In this example, since the stage movement is started for the first time, the same applies when the stage is stopped before the first time.

  Here, after the stage movement is stopped, it is necessary to repeat the averaging process at least four times until the display of the fine image from which the flicker noise disappears by the averaging process. It is assumed that temporary fine image data is displayed, and thereafter stable fine image data is displayed. Furthermore, after the generation of the still image generation instruction signal, the averaging process eliminates the flicker noise, and it is necessary to repeat the averaging process five times until high-definition still image data is displayed. It is assumed that temporary high-definition image data including flicker noise is displayed.

During the stage movement, the frame image data D ′ _{1 in} which the first binning process is executed is created by the first display process. In the image buffer memory 24, image data that has been created and stored in the past is discarded (to prevent image blurring), and temporary fine image data C ₀ (blank paper fine image data) is stored. Then, the frame image data D ′ ₁ is displayed on the display screen 23. The image data D ′ ₁ includes flicker noise and is rough image data subjected to binning processing. However, since the image data D ′ ₁ is excellent in followability, it is possible to display a state change during movement.
Similarly, the frame image data D ′ ₂ (D ′ ₃ ) is created by the display process of the second display process (third display process), and the state change during the stage movement is displayed on the display device 23 with good followability. Is done.
FIG. 12A shows an image example at this time, and a coarse image including flickering noise is displayed. Then, after the third display process, the stage 16 is stopped.

By the fourth display process, the frame image data D′ ₄ subjected to the binning process is created. An averaging process is executed using the averaging process image data stored in the image buffer memory 24 and the latest frame image data D′ ₄ (however, the averaging display image data is stored in the fourth display process). Since it does not exist, it is carried out formally), and temporary fine image data C ′ ₄ is created.
When the transition from the third display process to the fourth display process is performed, the binning process itself continues to be executed, so that no waiting time occurs when the binning process is canceled.
Thereafter, in the fifth display process (sixth display process), the temporary fine image data C ′ ₅ (C ′ ₆ ) is updated with the frame image data D ₅ (D ₆ ). In the seventh display process, since the averaging process is performed using the required number of data, fine image data C ′ ₇ without flickering noise is obtained. This is stored in the image buffer memory 24 and the latest fine image data C ′ ₇ is displayed on the screen of the display device 23. FIG. 12B shows an image example at this time, and fine image data without flickering noise is displayed.
Subsequently, in the eighth display process, the frame image data D ′ ₈ is updated, and the fine image data C ′ ₈ is displayed.
Then, after the eighth display process, a still image creation instruction signal is generated.

Binning processing is canceled when a still image creation instruction signal is generated. In 9th display processing is discarded images stored in the past in the image buffer memory 24 data, the frame image data D ₉ newly created by releasing the binning process is created. Then, since the binning process is canceled by the averaging processing, high-definition image data C ₉ is accumulated in the temporary (although 9th display process by the frame image data D ₉ and an averaging processing image data, the average previous Since the image processing image data is not accumulated, the averaging processing is performed formally). Then, temporary high-definition image data C ₉ is displayed on the screen of the display device 23.
With the cancellation of the binning process, there may be a waiting time of several seconds for switching. However, as described above, the waiting time at this point is more time-consuming for the operator than the fourth display process. Don't be.

From the tenth display process to the twelfth display process, frame image data D ₉ , D ₁₀ , D ₁₁ , D ₁₂ from which the binning process has been canceled are created, and the averaging process is repeated to tentative high-definition image data Accumulated with C ₉ , C ₁₀ , C ₁₁ , C ₁₂ . Frame image data D ₁₃ to the binning process is canceled is created by the 13 th display process, the high-resolution image data C ₁₃ averaging processing times required for high definition image data is made is created, which is displayed It is displayed on the screen 23.
FIG. 12C shows an example of an image at this time, and a high-definition image is displayed without flickering noise.

  With the above processing operation, while the visual field is fluctuating due to the stage movement, it is possible to display a moving image with good follow-up to the fluctuation, and after the stage is stopped and the visual field is fixed, the averaging process is performed. High-definition images can be displayed, and when creating still image data, a high-definition image with the binning process canceled is created, so that optimal display can be realized according to the situation, and binning Since it is possible not to worry about the waiting time associated with the process switching, it is possible to provide an easy-to-use X-ray inspection apparatus.

  In the above-described embodiment, the number of averaging processes when the binning process is executed is increased from the number of averaging processes when the binning process is canceled. During the process, it may be set as appropriate according to the image quality required during the still image capturing process.

  Further, in the above embodiment, when there is a still image creation instruction signal, the binning process is released from the executed state. However, when the operation by the automatic sequence program is performed, the field of view is fixed. If sufficient time is not available, still image creation may be performed while the binning process is performed without canceling the binning process.

  In the above description, the flicker noise is eliminated by the averaging process. However, the same applies to the case where the recursive filter process as described in the first embodiment is used instead. In this case, the averaging process of S306, S309, and S314 in FIG. 10 is replaced with the recursive filter process.

  The present invention can be used for an X-ray inspection apparatus that switches display modes depending on whether the visual field is changing or the visual field is fixed.

The block diagram which shows the structure of the X-ray inspection apparatus which is one Embodiment of this invention. The flowchart of the measurement operation | movement (display processing operation) by the X-ray inspection apparatus of FIG. The figure explaining the state of the display screen for every display processing by the X-ray inspection apparatus of FIG. 1, and an image buffer memory. The figure explaining the example of an image displayed on a display screen. The block diagram which shows the structure of the X-ray inspection apparatus which is other one Embodiment of this invention. 6 is a flowchart of a measurement operation (display processing operation) by the X-ray inspection apparatus in FIG. 5. The figure explaining the state of the display screen for every display processing by the X-ray inspection apparatus of FIG. 5, and an image buffer memory. The figure explaining the averaging process or recursive filter process which the conventional X-ray inspection apparatus performs. The block diagram which shows the structure of the X-ray inspection apparatus which is other one Embodiment of this invention. 10 is a flowchart of a measurement operation (display processing operation) by the X-ray inspection apparatus in FIG. 9. The figure explaining the state of the display screen and image buffer memory for every display processing by the X-ray inspection apparatus of FIG. The figure explaining the example of an image displayed on a display screen.

1, 2, 3: X-ray inspection device 11: X-ray generator 12: X-ray detector 13: X-ray measurement optical system 14: Field adjustment mechanism 16: Stage 17: Three-dimensional drive mechanism 22: Input device 23: Display Device 24: Image buffer memory 31: Frame image data creation unit 32: Fine image data creation unit (for recursive filter processing)
33: Field adjustment control unit 34: Field variation determination unit 35: Image mode switching unit 36: Accumulated image data erasing unit 37: Fine image data creation unit (for averaging processing)
41: Frame image data creation unit 42: Fine image data creation unit 43: Still image data creation unit 44: Still image creation instruction unit 45: Binning processing control unit 46: Image mode switching unit

Claims (2)

An X-ray measurement optical system comprising an X-ray generator for irradiating the object to be measured with X-rays for fluoroscopy and an X-ray detector for capturing a fluoroscopic X-ray image of the object to be measured;
A frame image data creation unit that executes binning processing based on a video signal captured by an X-ray detector or cancels binning processing and repeatedly creates frame image data of a fluoroscopic X-ray image one by one; ,
Either the past image data created by performing the recursive filter process on the frame image data created by executing the binning process or at least one past frame image data created by executing the binning process is finely defined. Recursive filter processing using image data for image data creation stored in an image buffer memory, and using the accumulated image data for fine image data creation and the latest frame image data of a fluoroscopic X-ray image created by executing binning processing Or a fine image data creation unit that creates fine image data that has been averaged,
Either past image data created by recursive filter processing of frame image data created by canceling binning processing or at least one past frame image data created by canceling binning processing is stopped. Recursive filter processing using image data for image data creation stored in the image buffer memory, and using the stored still image data creation image data and the latest perspective X-ray image frame image data created by canceling the binning process, Alternatively, a still image data creation unit that creates the averaged still image data;
A display device for displaying image data;
A field adjustment unit that adjusts the positional relationship between the object to be measured and the X-ray measurement optical system to change the measurement field of view of the object to be measured;
A visual field variation determination unit that determines whether or not the measurement visual field varies,
A still image creation instruction unit for generating a still image creation instruction signal;
A binning processing control unit that switches the presence / absence of the binning process to the frame image data generation unit based on the presence / absence of an instruction signal for still image generation;
When it is determined that there is no still image creation instruction signal and the field of view is fluctuating, frame image data is displayed. When it is determined that there is no still image instruction signal and the field of view is constant, fine image data is displayed. And an image mode switching unit for displaying still image data when there is a still image instruction signal. Definition image data creating unit according to claim 1, characterized in that discarding the image data for definition image created accumulated in the image buffer memory when the measuring field by the field variation determining unit is determined to be varied X-ray inspection apparatus described in 1.