JP5057543B2 - Image processing apparatus, control method therefor, and program - Google Patents

Description

  The present invention relates to an image processing apparatus that reads pixel data from a detector that detects radiation emitted from a radiation source and executes image processing, a control method thereof, and a program.

  In the field of X-ray imaging diagnosis, instead of conventional imaging with a silver salt film, I.D. I. (Image Intensifier)-TV systems have become widely used. However, I.I. I. -The size of the shooting area of the TV system is I. In response to the demand for enlargement of the photographing area, a size of about 16 inches is manufactured. However, I.I. I. When the aperture is increased, not only the imaging region but also the depth of the detection system increases. Accordingly, the weight is inevitably increased, and the X-ray diagnostic apparatus becomes difficult to use.

  Moreover, since it is a tube structure, the lifetime is also short. Such I.V. I. -To compensate for the shortcomings of TV systems, X-ray diagnostic apparatuses using thin X-ray flat panel detectors are promising. The X-ray plane detector is a detector that can read out an X-ray intensity distribution projected on a plane as data for each pixel.

  There are two types of this X-ray flat panel detector, using an indirect type that detects X-rays by converting them into wavelengths of light that can be detected by a photoelectric conversion element using a phosphor, and a semiconductor such as selenium. The direct type that directly detects X-rays.

  In this X-ray flat panel detector, Patent Document 1 discloses a technique of reading out only a fast-moving region of a subject such as a child's heart that moves fast at a higher speed.

Further, as a method for extracting only a fast moving region, there is a method disclosed in Patent Document 2. First, test bombardment is performed to recognize the irradiation field area. Then, the irradiation field is tracked every frame, and it is determined whether or not the irradiation field region has shifted from the aperture information of the X-ray tube and the distance between the X-ray tube and the flat detector. If the result of the determination is that there is a shift, all pixels are read once again and the irradiation field recognition process is performed.
Japanese Patent Laid-Open No. 07-068673 JP 11-318877 A

  An advantage of imaging using a thin X-ray flat panel detector is that the degree of freedom in arrangement is improved. Specifically, an imaging technique similar to that of a conventional film cassette can be applied to fluoroscopy using an X-ray flat panel detector (hereinafter, cassette type). Here, in the case of the cassette type, it is difficult to determine whether or not the irradiation field region has shifted, instead of having a high degree of freedom in arrangement. That is, when the cassette type is used by being fixed to a mounting portion such as a C-arm, the aperture information of the X-ray tube can be controlled, but the distance from the cassette type cannot be accurately detected.

  However, it is the portability that the cassette type is most effective. Therefore, it is most often assumed that the cassette type is freely arranged with respect to the X-ray tube and the X-ray incident angle changes variously. For example, as shown in FIG. 11, when imaging is performed in a state of being bent down, the aperture information of the X-ray tube attached to the X-ray explosive device 1111 is transmitted to the flat detector 1112. It is not possible to use it because it does not know where it is irradiated. Also, the distance between the X-ray tube and the flat detector 1112 cannot be detected.

  The present invention has been made to solve the above-described problem, and an image processing apparatus capable of efficiently and accurately performing a pixel readout operation related to an irradiation field region and improving the total throughput, and the image processing apparatus It is an object to provide a control method and a program.

In order to achieve the above object, an image processing apparatus according to the present invention comprises the following arrangement. That is,
An image processing apparatus that reads out pixel data from a detector that detects radiation emitted from a radiation source and executes image processing,
Control means for controlling switching between a full area readout mode for reading out pixel data of the whole detection area of the detector and a partial area readout mode for reading out pixel data of the partial area of the detection area based on a designated cycle. When,
Reading means for reading out pixel data of the detection area of the detector based on a reading mode specified by the control means;
Recognizing means for recognizing an irradiation field area of the radiation with respect to the detector based on an image composed of pixel data read by the reading means in the whole area reading mode;
Generating means for generating a display image corresponding to the irradiation field area recognized by the recognition means,
When the all area read mode is specified,
The reading means reads out pixel data by thinning out a part of the pixel data group to be read from the detector for one frame,
It said generating means, by resolution conversion irradiation Noga image corresponding to the exposure field region, and generates the irradiation field image that is the resolution conversion as the display image.

Preferably, storage means for storing irradiation field area information related to the irradiation field area recognized by the recognition means is further provided to update the partial area in the partial area reading mode .

  Preferably, when the all-region reading mode is designated, the reading means reads out a part of the pixel data group to be read from the detector.

  Preferably, when the all-region reading mode is designated, the reading unit adds and reads a part of the pixel data group to be read from the detector.

Preferably, when the partial region readout mode is designated, the readout unit reads out pixel data of the partial detection region of the detector based on irradiation field region information stored in the storage unit. .

Also, preferably, in the partial region reading mode, the first irradiation field region extracted by the read of said read means based on the irradiation field area information stored in said storage means, thereafter, recognition by said recognition means based on the second irradiation field recognized running, further comprising correcting means for correcting the irradiation field area information stored in the storage means.

Preferably, setting means for setting a feedback area including the center of the irradiation field area recognized by the recognition means,
And adjusting means for adjusting a set value relating to radiation of the radiation source based on pixel data detected in a detection area of the detector corresponding to the feedback area set by the setting means.

In order to achieve the above object, a method for controlling an image processing apparatus according to the present invention comprises the following arrangement. That is,
A control method for an image processing apparatus that reads out pixel data from a detector that detects radiation emitted from a radiation source and executes image processing,
Based on a specified cycle, the control means switches between an entire region reading mode for reading pixel data of the entire detection region of the detector and a partial region reading mode for reading pixel data of the partial region of the detection region. A control process to control;
A reading step for reading out pixel data of a detection region of the detector based on a reading mode specified by the control step;
A recognition step of recognizing an irradiation field region of the radiation with respect to the detector based on an image composed of pixel data read out in the reading step in the full-region reading mode;
A generating step of generating a display image corresponding to the irradiation field area recognized in the recognition step;
When the all area read mode is specified,
The reading step reads out pixel data by thinning out a part of a pixel data group to be read for one frame from the detector,
The generating step, by resolution conversion irradiation Noga image corresponding to the exposure field region, and generates the irradiation field image that is the resolution conversion as the display image.

In order to achieve the above object, a computer program according to the present invention comprises the following arrangement. That is,
Computer
An image processing apparatus that reads out pixel data from a detector that detects radiation emitted from a radiation source and executes image processing,
Control means for controlling switching between a full area readout mode for reading out pixel data of the whole detection area of the detector and a partial area readout mode for reading out pixel data of the partial area of the detection area based on a designated cycle. When,
Reading means for reading out pixel data of the detection area of the detector based on a reading mode specified by the control means;
Recognizing means for recognizing an irradiation field area of the radiation with respect to the detector based on an image composed of pixel data read by the reading means in the whole area reading mode;
To function as a generating unit that generates a display image corresponding to the irradiation field recognized by said recognition means,
When the all area read mode is specified,
The reading means reads out pixel data by thinning out a part of the pixel data group to be read from the detector for one frame,
It said generating means, by resolution conversion irradiation Noga image corresponding to the exposure field region, and generates the irradiation field image that is the resolution conversion as the display image.

  According to the present invention, it is possible to provide an image processing apparatus, a control method thereof, and a program capable of efficiently and accurately performing a pixel reading operation related to an irradiation field region and improving the total throughput.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  In the present invention, in order to solve the above problem, the method is not a method of recognizing an irradiation field region based on the aperture information of the X-ray tube and the distance between the X-ray tube and the flat detector, but a captured image obtained from the X-ray flat detector A method for recognizing the irradiation field is proposed.

  In the present embodiment, the radiation image is described by taking an example of an image captured using X-rays emitted from the X-ray source. However, the present invention is not limited to this, and other radiation sources are used. The present invention can also be applied to images taken in this manner.

  In this case, using only the captured image is effective because it is not necessary to consider the positional relationship with the X-ray tube even in the case of using the cassette type.

  Specifically, the entire area of the flat detector is read periodically. For example, the entire area reading is executed in the first frame, and the irradiation field recognition process is executed. In the second and subsequent frames, the irradiation field recognized in the first frame is used as it is, and partial area reading of only the irradiation field is executed.

  Then, the entire area reading is executed again in the T + 1 frame, and the irradiation field recognition process is executed. After the T + 2th frame, partial area reading is executed using the irradiation field recognized in the T + 1th frame. Further, the entire area reading is executed again in the 2T + 1 frame.

  As described above, by executing the entire area reading for each period T, even when the plane detector moves and the irradiation field area is shifted, it can be confirmed again and corrected. Furthermore, until now, simply tracking the irradiation field has been unable to cope with changes in the size and shape of the irradiation field due to changes in the aperture of the X-ray tube. On the other hand, according to the present invention, even when the irradiation field size or shape changes, it can be confirmed again and corrected.

  In addition, the partial area reading shortens the time for reading data from the flat panel detector and makes it possible to achieve a high frame rate. Therefore, in order to take advantage of this effect, a configuration has been proposed in which the reading time is reduced even when the entire area reading is executed. Specifically, the entire frame is roughly read. The rough reading here refers to reading by thinning out pixels or line addition reading. Therefore, even if the entire area reading is executed, the reading time can be suppressed and a high frame rate can be achieved.

  First, a configuration diagram of an X-ray fluoroscopic apparatus according to the present invention will be described with reference to FIG.

  FIG. 1 is a diagram showing the configuration of the X-ray fluoroscopic apparatus of the present invention.

  The X-ray fluoroscopic apparatus is composed of a reading mode control unit 101, an image reading unit 102, an irradiation field recognition processing unit 103, a display image processing unit 104, and an image display unit 105.

  The read mode control unit 101 receives as input the switching information indicating that the mode is switched every frame or every second, and the current number of frames to be captured or the shooting time. Further, a readout method signal for instructing execution of either full area readout or partial area readout of pixel data to the detection area of the detector is output.

  The image reading unit 102 receives a reading method signal and outputs a read image according to the reading method. When the reading method is all-region reading, the read image is input to the irradiation field recognition processing unit 103, irradiation field recognition processing is performed, and the recognized irradiation field is output.

  The display image processing unit 104 receives the read image and the irradiation field. Only the irradiation field is cut out from the input image, display image processing such as gradation correction is added to the cut out irradiation field image, and an enlarged image is output.

  In the image display unit 105, an image obtained by performing image processing on the irradiation field image is input and displayed on the display unit 209 (real time monitor: see FIG. 2). When the reading method is partial area reading, the irradiation field area information of the previous frame is also input, and only the designated irradiation field area is read and output.

  Next, a hardware configuration for realizing the X-ray fluoroscopic apparatus will be described with reference to FIG.

  FIG. 2 is a diagram showing a hardware configuration for realizing the X-ray fluoroscopic imaging apparatus of the present invention.

  In FIG. 2, the control PC 201 and the flat detector 202 are connected via an optical fiber 222. In addition, an image processing unit 210, a display unit 209, a storage unit 211, and a network interface (NIC) unit 212 are connected to the optical fiber 222.

  Here, the storage unit 211 is realized by a mass storage device such as a hard disk drive (HDD), for example.

  For example, a CPU (central processing unit) 203, a RAM 204, a ROM 205, an input unit 206, a display unit 207 (operation monitor), and a storage unit 208 are connected to the control PC 201, for example. A command can be transmitted to devices such as the flat panel detector 202 and the image processing unit 210 via the control PC 201.

  The read mode control unit 101 in FIG. 1 is stored in the storage unit 208 as a software module, and is read into the RAM 205 and executed under the control of the CPU 203. The image reading unit 102 is implemented as hardware in the flat detector 202. The irradiation field recognition processing unit 103 and the display image processing unit 104 are mounted on the image processing unit 210 as an image processing board. The image display unit 105 is realized by the display unit 209.

  It should be noted that the present invention is not limited to the above-described configuration, and can be realized entirely by dedicated hardware. In this case, all the components in FIG. 1 may be realized as dedicated hardware, or may be configured as a single device. What is necessary is just to perform the optimal mounting according to the objective.

  Next, the operation of the image capturing apparatus will be described according to some embodiments.

<Embodiment 1>
The operation of the image capturing apparatus according to the first embodiment will be described with reference to FIG.

  FIG. 3 is a flowchart showing the operation of the image photographing apparatus according to the first embodiment of the present invention.

  First, switching information indicating how many frames are to be switched between the full region read mode and the partial region read mode is input to the read mode control unit 101. That is, the setting of the cycle T indicating how many frames the irradiation field recognition process is performed is executed (step S301). For example, when the irradiation field recognition process is performed once every 10 frames, the cycle T = 10 is set.

  Next, as preparation for photographing, here, the photographing frame counter I is set to 1 (step S302). Then, shooting is started (step S303). When shooting is started, frame information indicating what frame is currently shot is input to the readout mode control unit 101. Using this frame information, n is set to an integer other than negative, and it is checked whether or not the determination formula nT + 1 = I is satisfied (step S304).

  When this determination formula is satisfied (YES in step S304), “all area read mode” is output as the mode determination result of the read mode control unit 101. If this determination formula is not satisfied (NO in step S304), “partial region read mode” is output as the mode determination result of the read mode control unit 101. Since there is no information about the irradiation field in the first frame, the entire area is always read out. In addition, since the determination formula is established when n = 0, the “all area read mode” is output.

  A mode determination result that is an output of the reading mode control unit 101 is input to the image reading unit 102. In the first frame, since the input mode determination result is the “all region reading mode”, the image reading unit 102 executes the all region reading process (step S305). Here, if the whole area reading process is normally executed, the frame rate is lowered as compared with the partial area reading process. Therefore, the entire area reading is performed roughly. The purpose is to prevent the frame rate from dropping even when the entire area reading mode is set by performing rough reading.

  Here, an example of a rough reading execution method will be described with reference to FIG.

  FIG. 4 is a diagram illustrating an example of a rough reading execution method according to the first embodiment of the present invention.

  FIG. 4 shows two examples of rough reading.

  FIG. 4A shows thinning reading from the entire area of the flat detector. This reads out pixels while skipping line by line for the image to be processed like the image 411 (only the pixels indicated by ◯ in the image 411 are read out). In this case, since the number of read lines is halved, the read time is approximately halved compared to when the entire area is read. The read image 412 read out in this way becomes the output of the image reading unit 102.

  FIG. 4B shows the addition reading from the entire area of the flat detector. This is performed by adding a plurality of adjacent pixels in the line direction and reading the image to be processed like the image 421. In this case, since the number of read clocks is halved, the read time is approximately halved compared to when the entire area is read. The read image 422 read out in this way becomes the output of the image reading unit 102.

  The read image output from the image reading unit 102 is used as the input to the irradiation field recognition processing unit 103. The irradiation field recognition processing unit 103 first executes an image size conversion process for converting the roughly read image to the original image size (step S306).

  An example of this image size conversion process will be described with reference to FIG.

  FIG. 5 is a diagram showing an example of image size conversion processing according to the first embodiment of the present invention.

  FIG. 5A shows a case where an image size conversion process is performed on the image 512 obtained by the thinning-out reading of FIG. In this case, the image 512 is enlarged and converted to an image 513 having the original image size. In this enlargement method, there is simply a method in which the pixels indicated by ◯ are arranged at their original positions, and the blank pixel is copied to the upper adjacent pixel (or the lower adjacent pixel when there is no pixel on the left). Also, other methods such as dilation processing and interpolation may be used, but it is better to avoid those that require processing time.

  FIG. 5B shows a case where an image size conversion process is performed on the image 522 obtained by the addition reading of FIG. In this case, the image 522 is enlarged and converted to the image 523 having the original image size. This enlargement method can be realized by the same method as in the case of thinning-out reading.

  Returning to the description of FIG.

  Next, an irradiation field recognition process is executed from the image after the image size conversion process (step S307). Here, the method is not particularly limited, but for example, a method described in JP-A-7-327596 can be used. Moreover, it is possible to recognize the irradiation field simply by using only the first and second derivatives.

  When the irradiation field is recognized using these methods, the irradiation field area information (position, shape, etc.) is stored in the memory 313. The memory 313 is realized by the RAM 204 or the storage unit 208, for example. The irradiation field area information on the memory 313 is used from the next frame. This irradiation field recognition process is characterized in that the irradiation field is recognized only by information of the captured image obtained from the flat detector 202. By doing so, the cassette type can be used.

  Next, using the irradiation field area information, an irradiation field extraction process for cutting out the irradiation field from the image after the image size conversion process is executed (step S308). The extracted irradiation field image is used as an output of the irradiation field recognition processing unit 103.

  The irradiation field image that is the output of the irradiation field recognition processing unit 103 is used as the input of the display image processing unit 104. The display image processing unit 104 executes display size setting processing for determining the display size in order to display the irradiation field image, which is the output of the irradiation field recognition processing unit 103, on the entire display screen (step S310). .

  The display size is changed so as to be displayed at the maximum by comparing the resolution of the display unit 209 with the resolution of the irradiation field image. For example, when the resolution of the display unit 209 is A × B pixels and the resolution of the irradiation field image is C × D, the irradiation field image is compared with A / C and B / D, and the smaller magnification is corrected. Add rotation and flipping if necessary. Further, gradation correction processing is also performed to improve visibility.

  For example, when A / C <B / D, a display image (A / C> α) obtained by multiplying the irradiation field image by (A / C−α) is output from the display image processing unit 104. To do. At this time, the photographing frame counter I is incremented and a new photographing is waited (step S311). Further, the display size magnification (A / C-α), the rotation angle, and the reverse ON / OFF are stored in the memory 313.

  The display image output from the display image processing unit 104 is input to the image display unit 105, and the display image is displayed on the display unit 209 (step S312).

  Next, the second frame is processed. Similarly, in the second frame, the readout mode control unit 101 receives frame information indicating what frame is currently being shot. Then, using this frame information, it is checked whether or not the judgment formula nT + 1 = I is satisfied (step S304). Since the determination formula is not satisfied in the second frame, the “partial region readout mode” is the output of the readout mode control unit 101.

  A mode determination result that is an output of the reading mode control unit 101 is input to the image reading unit 102. In the second frame, since the input mode determination result is the “partial region readout mode”, the image readout unit 102 executes partial region readout (step S309).

  Here, in the partial area reading process, first, irradiation field area information is input from the memory 313. The flat detector 202 performs partial area reading only for the irradiation field portion (range) defined by the irradiation field area information. By executing the partial area reading, unnecessary pixels can be read idle or only the necessary lines can be read, so that the reading speed is improved.

  The method for reading the partial area is not particularly limited here, but for example, a method disclosed in Japanese Patent Laid-Open No. 7-068673 can be used. Also in this partial area reading, the irradiation field is recognized only by the information of the captured image obtained from the flat detector 202. By doing so, the cassette type can be used. In this way, a read image obtained by partial area reading becomes an output of the image reading unit 102.

  The read image output from the image reading unit 102 is used as the input to the display image processing unit 104. The display image processing unit 104 executes display size setting processing for determining the display size in order to display the read image output from the image reading unit 102 on the entire display screen (step S310).

  As the display size, the display size magnification, the rotation angle, and the reverse ON / OFF stored in the memory 313 are read, the read image is converted to this magnification, gradation correction processing is executed, and a display image is created. This display image is used as the output of the display image processing unit 104. At this time, the photographing frame counter I is incremented and a new photographing is waited (step S311).

  The display image output from the display image processing unit 104 is input to the image display unit 105, and the display image is displayed on the display unit 209 (step S312).

  Similar processing is repeated for the third and subsequent frames. Then, when the discriminant of step S304 is established, the entire area reading is executed, and the irradiation field recognition process is further executed to re-recognize the irradiation field. On the other hand, when the discriminant of step S304 is not satisfied, the irradiation field recognition process is not performed, and partial area reading is executed using the irradiation field area information stored in the memory 313.

  Therefore, the entire area reading is executed next at the T + 1 frame after the cycle T. In the T + 1 frame, the same processing as that in the first frame is performed to re-recognize the irradiation field, and correspond to the movement of the irradiation field and the change in size and shape.

  As described above, according to the first embodiment, it is possible to continue to cut out an accurate irradiation field while realizing high-speed reading by executing all-region reading at every cycle T. Further, since the irradiation field is recognized based on only the information of the captured image obtained from the flat detector, the present invention can be used with an independent flat detector such as a cassette type.

<Embodiment 2>
The operation of the image capturing apparatus according to the second embodiment will be described with reference to FIG.

  FIG. 6 is a flowchart showing the operation of the image photographing apparatus according to the second embodiment of the present invention.

  First, switching information indicating how many frames are to be switched between the full region read mode and the partial region read mode is input to the read mode control unit 101. That is, the setting of the cycle T indicating how many seconds the irradiation field recognition process is performed is executed (step S601). For example, when the irradiation field recognition process is executed once every 1000 milliseconds, the cycle T = 1000 is set.

Next, as a preparation for photographing, here, the photographing frame counter I is set to 1 and the offset time I ₀ = 1 (step S602). Then, shooting is started (step S603). When shooting is started, frame information indicating what frame is currently shot is input to the readout mode control unit 101. Using this frame information, t is set as the time from the start of photographing, and it is checked whether or not the judgment formula t (I−I ₀ )> T is satisfied (step S604).

  When this determination formula is satisfied (YES in step S604), “all region read mode” is output as the mode determination result of the read mode control unit 101. If this determination formula is not satisfied (NO in step S604), “partial region read mode” is output as the mode determination result of the read mode control unit 101. Since there is no information about the irradiation field in the first frame, the entire area is always read out. Therefore, the “all area read mode” is output.

  A mode determination result that is an output of the reading mode control unit 101 is input to the image reading unit 102. In the first frame, since the input mode determination result is the “all region reading mode”, the image reading unit 102 executes the all region reading process (step S605). Here, if the entire area reading process is executed normally, the set frame rate cannot be achieved. Therefore, when the entire area reading is executed, the process is executed across a plurality of frames. That is, a process for prohibiting shooting of the next frame after the entire area reading is executed.

  This process will be described with reference to FIG.

  FIG. 7 is a diagram for explaining frame processing according to the second embodiment of the present invention.

  In FIG. 7, the whole area reading is performed in the first frame and the fifth frame. Since the first frame is the whole area reading, the reading time takes longer than the partial area reading. Therefore, originally, shooting is not performed (prohibited) at the timing at which shooting of the second frame is performed, and the shooting time for that one frame is assigned to the reading time of the first frame.

  Therefore, the frame displayed on the display unit 209 starts with a delay of one frame. Next, the second frame (originally, the third frame shooting timing) is shot. Since the second frame is partial reading, the reading time is fast and it is displayed on the display unit 209 immediately. The same applies to the third frame and the fourth frame.

  Next, when the fifth frame is reached, reading of the entire area is performed again, so that two frames are assigned to the reading time and shooting is also skipped by one frame. On the display unit 209, the space for one frame is vacant, and thus the image of the fourth frame is displayed as it is. When the reading of the fifth frame image is completed, display is performed on the display unit 209. The rest is this repetition. In this way, the set frame rate is not actually reproduced completely, but it can be seen that it has been achieved. In this way, a read image obtained by reading the entire area becomes an output of the image reading unit 102.

  The read image output from the image reading unit 102 is used as the input to the irradiation field recognition processing unit 103. The image size conversion processing (step S606), irradiation field recognition processing (step S607), and irradiation field extraction processing (step S608) in the irradiation field recognition processing unit 103 are respectively steps S306, S307, and S308 of the first embodiment. Corresponding to Therefore, description of each of these processes is omitted.

  After the processing in step S608, the extracted irradiation field image is set as the output of the irradiation field recognition processing unit 103. Here, since the reading time is increased by one frame, the photographing frame counter I is incremented (step S609).

  The irradiation field image that is the output of the irradiation field recognition processing unit 103 is used as the input of the display image processing unit 104. The display size setting process (step S611) in the display image processing unit 104 corresponds to step S310 in the first embodiment, and thus the description thereof is omitted. Then, the irradiation field image converted into the display image is used as the output of the display image processing unit 104. At this time, the shooting frame counter I is incremented and a new shooting is waited (step S612). Further, the display size magnification (A / C-α), the rotation angle, and the reverse ON / OFF are stored in the memory 613.

  The display image output from the display image processing unit 104 is input to the image display unit 105, and the display image is displayed on the display unit 209 (step S613).

Next, the second frame is processed. Similarly, in the second frame, the readout mode control unit 101 receives frame information indicating what frame is currently being shot. Then, using this frame information, t is set as the time from the start of photographing, and it is checked whether or not the judgment formula t (I−I ₀ )> T is satisfied (step S604). Since the determination formula is not satisfied in the second frame, the “partial region readout mode” is the output of the readout mode control unit 101.

  A mode determination result that is an output of the reading mode control unit 101 is input to the image reading unit 102. In the second frame, since the input mode determination result is the “partial region reading mode”, the image reading unit 102 executes a partial region reading process (step S610).

  Here, the partial area reading process is the same as that of the first embodiment, and thus the description thereof is omitted. A read image obtained by partial area reading is output from the image reading unit 102.

  The read image output from the image reading unit 102 is used as the input to the display image processing unit 104. Since the display size setting process (step S611) in the display image processing unit 104 is the same as that in the first embodiment, the description thereof is omitted. An image obtained by converting the irradiation field image into a display image is used as an output of the display image processing unit 104. At this time, the shooting frame counter I is incremented and a new shooting is waited (step S612).

  The display image output from the display image processing unit 104 is input to the image display unit 105, and the display image is displayed on the display unit 209 (step S613).

  Similar processing is repeated for the third and subsequent frames. Then, when the discriminant of step S604 is satisfied, the entire area reading is executed, and the irradiation field recognition process is further executed to re-recognize the irradiation field. On the other hand, when the discriminant of step S604 is not satisfied, the irradiation field recognition process is not performed, and partial area reading is executed using the irradiation field area information stored in the memory 613.

  Therefore, the entire area reading is executed next at the T + 1 frame after the cycle T. In the T + 1 frame, the same processing as that in the first frame is performed to re-recognize the irradiation field, and correspond to the movement of the irradiation field and the change in size and shape.

  As described above, according to the second embodiment, it is possible to continue to cut out an accurate irradiation field while realizing high-speed reading by executing all-region reading at every cycle T. Further, since the irradiation field is recognized based on only the information of the captured image obtained from the flat detector, the present invention can be used with an independent flat detector such as a cassette type.

<Embodiment 3>
The operation of the image capturing apparatus according to the third embodiment will be described with reference to FIG.

  FIG. 8 is a flowchart showing the operation of the image photographing apparatus according to the third embodiment of the present invention.

  First, switching information indicating how many frames are to be switched between the full region read mode and the partial region read mode is input to the read mode control unit 101. That is, the setting of the period T indicating how many frames the irradiation field recognition process is performed is executed (step S801). For example, when the irradiation field recognition process is executed once every 10 frames, the cycle T = 10 is set.

  Next, as preparation for photographing, here, the photographing frame counter I is set to 1 (step S802). Then, shooting is started (step S803). When shooting is started, frame information indicating what frame is currently shot is input to the readout mode control unit 101. Using this frame information, n is set to an integer other than negative, and it is checked whether or not the judgment formula nT + 1 = I is satisfied (step S804).

  When this determination formula is satisfied (YES in step S804), “all region read mode” is output as the mode determination result of the read mode control unit 101. If this determination formula is not satisfied (NO in step S804), “partial region read mode” is output as the mode determination result of the read mode control unit 101. Since there is no information about the irradiation field in the first frame, the entire area is always read out. Since the determination formula is also established when n = 0, the “all area read mode” is output.

  Here, the entire area reading process is the same as that of the first embodiment, and thus the description thereof is omitted.

  Next, the second frame is processed. Similarly, in the second frame, the readout mode control unit 101 receives frame information indicating what frame is currently being shot. Then, using this frame information, it is checked whether or not the judgment formula nT + 1 = I is satisfied (step S804). Since the determination formula is not satisfied in the second frame, the “partial region readout mode” is the output of the readout mode control unit 101.

  A mode determination result that is an output of the reading mode control unit 101 is input to the image reading unit 102. In the second frame, since the input mode determination result is the “partial region reading mode”, the image reading unit 102 executes partial region reading (step S809).

  Here, in the partial area reading process, first, irradiation field area information is input from the memory 814. Only in this irradiation field portion, the flat detector 202 performs partial area reading. By executing partial area reading, unnecessary pixels can be read empty, or only necessary lines can be read, so that the reading speed is improved.

  The method for reading the partial area is not particularly limited here, but for example, a method disclosed in Japanese Patent Laid-Open No. 7-068673 can be used. Also in this partial area reading, the irradiation field is recognized only by the information of the captured image obtained from the flat detector 202. By doing so, the cassette type can be used. In this way, a read image obtained by partial area reading becomes an output of the image reading unit 102.

  The read image, which is the output of the image reading unit 102, is input to the irradiation field recognition processing unit 103. The irradiation field recognition processing unit 103 executes an irradiation field confirmation process to determine whether there is any irradiation field deviation (step S810).

  For example, an irradiation field region 901 in FIG. 9 is an example of a read image that is an output of the image reading unit 102. The white part is the irradiation field and the black part is outside the irradiation field. At this time, it can be seen that the irradiation field is shifted to the lower right as compared with the first frame.

  Therefore, the irradiation field is detected again for the irradiation field region 901. The detection method may be the same as the irradiation field recognition process in step S807. When a new irradiation field 902 is detected in the irradiation field 901, a movement amount P from the irradiation field region 901 to the irradiation field region 902 is calculated.

  By adding this to the irradiation field area information stored in the memory 814 and updating (correcting) it, the irradiation field in the next frame becomes more accurate. By executing partial area readout using the irradiation field area information updated from the next frame, partial area readout can be executed like the irradiation field area 903. Also here, the feature is that the irradiation field is recognized only by the information of the captured image obtained from the flat detector. The image reading unit 102 outputs the input read image as it is.

  The read image output from the image reading unit 102 is used as the input to the display image processing unit 104. Since the display size setting process (step S811) in the display image processing unit 104 is the same as that in the first embodiment, the description thereof is omitted. An image obtained by converting the irradiation field image into a display image is used as an output of the display image processing unit 104. At this time, the photographing frame counter I is incremented, and a new photographing is waited (step S812).

  The display image that is the output of the display image processing unit 104 is input to the image display unit 105, and the display image is displayed on the display unit 209 (step S813).

  Similar processing is repeated for the third and subsequent frames. Then, when the discriminant of step S804 is established, the entire area reading is executed, and the irradiation field area process is further executed to re-recognize the irradiation field. On the other hand, when the determination formula of step S804 is not satisfied, the irradiation field recognition process is not performed, and partial area reading is executed using the irradiation field area information stored in the memory 814.

  As described above, according to the third embodiment, in addition to the effects described in the first embodiment, the presence or absence of the irradiation field shift in the irradiation field region is confirmed, and the irradiation field region is corrected according to the presence or absence. By doing so, processing can be executed using a more accurate irradiation field region.

<Embodiment 4>
The following application examples can be considered by cutting out the irradiation field by the method described in the first to third embodiments. FIG. 10 shows an example used in automatic X-ray control or automatic brightness control. Here, the center coordinates (Sx, Sy) of the irradiation field region 1001 are used. Before imaging, the feedback area 1002 is set as a 2M × 2N area centered on (Sx, Sy), and the irradiation field area 1001 and the feedback area 1002 are associated with each other.

  During imaging, the pixel values in the feedback area 1002 are fed back to the fluoroscopic imaging apparatus, and set values such as the current and voltage of the X-ray tube are adjusted so that the amount of noise in the feedback area 1002 is constant. By associating the irradiation field region 1001 and the feedback region 1002, even if the irradiation field moves, it is possible to position the irradiation field with reference to the feedback region 1002, and the image displayed on the display unit is always optimal. It will be a thing.

<Embodiment 5>
The most common technique for non-invasively observing the inside of a human body and used for medical diagnosis is to directly image the transmittance distribution of radiation (X-rays) that has passed through the human body.

  There are various methods. For example, there is a conventional method of imaging a fluorescence distribution resulting from X-rays reaching a phosphor with a silver salt film. Further, there is a method in which photoelectrons due to fluorescence are amplified by a photomultiplier tube and visualized with a TV camera. Further, there is a method in which latent image information produced by an X-ray intensity distribution on a photostimulable phosphor is excited with a laser beam to be read and visualized. Furthermore, recently, with the advancement of semiconductor technology, a free-formation generated in a semiconductor layer or heavy metal by fluorescence or X-ray irradiation using a flat detector composed of a large-scale solid-state imaging device that can encompass the entire human body. There is a method for imaging the spatial distribution of electrons.

  In the flat panel detector, the charge obtained by photoelectrically converting the fluorescence or the charge obtained by collecting the free electrons at a high potential is temporarily stored in capacitors corresponding to pixels distributed in a matrix on the image receiving surface. Thereafter, the switching transistor (TFT: Thin Film Transistor) formed on the thin film is sequentially energized (scanned) to extract image information as a collection of one-dimensional data.

  FIG. 12 shows more specifically the reading operation by the scanning of the flat detector.

  In the flat panel detector, functional elements distributed in an N × M matrix indicated by reference numeral 1101 represent pixel elements. More specifically, as shown in FIG. 13A, this is an element including a capacitor 1201 having a storage Cx capacity and a TFT 1202.

  Although not shown, charge is accumulated in the capacitor 1201 from a photoelectric conversion device typified by a photodiode that converts fluorescence from a phosphor caused by X-rays into an electrical signal. Alternatively, the capacitor 1201 accumulates charges obtained by collecting free electrons generated when a semiconductor layer or the like captures X-ray energetic particles flying at a high potential.

  The M functional elements shown by reference numeral 1103 in FIG. 12 are output holding units. Specifically, as shown in FIG. 13B, this is a unit having an output holding capacitor 1204 having a capacitance of Co and a signal resetting transistor 1203.

  A block denoted by reference numeral 1102 in FIG. 12 is a sub-scanning selection control circuit configured to sequentially select selection control signals 1 to N for simultaneously selecting one line of pixel elements arranged in a matrix.

  This operation will be specifically described with reference to FIG.

  FIG. 14 shows the signal states of the selection control signals 1 to N of the sub-scanning selection control circuit 1102 according to each timing. Numbers 1 to N indicated by reference numeral 1110 indicate signal states at each timing.

  At timing 1, only the selection control signal 1 is in the ON state and only the first row data is transferred, and at timing 2, only 2 is in the ON state and only the second row data is transferred. Such control is repeated N times.

  The time for which the control signal 1110 is held in the ON state is that the capacitor Cx in FIG. 13A and the capacitor Co in FIG. 13B are substantially connected in parallel through the conduction resistance and the signal line resistance of the TFT 1202. It is time to reach a sufficient equilibrium state.

If the charge accumulated in a certain pixel is Q ₁ , the output voltage V ₁ is
V ₁ = Q ₁ / (Cx + Co) (Formula 1)
It becomes. Also, assuming that the accumulated charge of another pixel is Q ₂ , the output voltage V ₂ is
V ₂ = Q ₂ / (Cx + Co) (Formula 2)
It becomes. Here, generally, the capacitance of the capacitor on the pixel is very small, and there is a condition that Cx << Co.
V ₁ = Q ₁ / Co (Formula 3)
V ₂ = Q ₂ / Co (Formula 4)
It becomes.

  Returning to the description of FIG.

  A block denoted by reference numeral 1104 is a main scanning selection control circuit that outputs one line at a time, is held by an output holding unit 1103, and sequentially outputs M potential signals as image output signals 1105. The main scanning selection control circuit 1105 sequentially selects each input value and outputs it as an image output signal 1105. The image output signal 1105 is image information that is a one-dimensional analog signal (video signal).

  Next, an X-ray imaging operation will be described.

  FIG. 15 shows a state of actual X-ray imaging, and the flat detector 2201 incorporates the flat detector described in FIG. The flat detector 2201 is connected to the control device 2204, and the pixel data of the flat detector 2201 is transferred to the control device 2201 after A / D conversion, and is displayed and stored.

  An X-ray tube 2203 serving as a radiation source diffuses and generates X-rays from a single point by irradiating an anode with a high-voltage electron beam. The aperture device 2202 defines an irradiation range of X-rays that generate diffusion. The aperture device 2202 is made of a substance that does not transmit X-rays, such as lead, and can move to define an irradiation range. Thereby, the X-ray is narrowed down to a range 2205 (broken line range). Hereinafter, this range 2205 is referred to as an irradiation field stop.

  Next, details of the flat detector 2201 and its peripheral configuration will be described with reference to FIG.

  In FIG. 16, a sub-scanning selection control circuit 1102 in FIG. 12 is configured by a driver 2111 and a shift register 2212 with respect to the flat detector 2210 (the flat detector 2201 in FIG. 15). Similarly, the multiplexer 2213 and the shift register 2214 constitute the main scanning direction selection circuit 1104 in FIG.

  When the X-ray is focused on the range 2215 (irradiation field range (area)), it is not necessary to read out the entire area of the flat detector 2210, so control is performed to read out only the sub-scanning range 2217 and the main scanning range 2218. Just do it. The read information is transferred as image data to an external device through the A / D converter 2219 and the interface (I / F) 2216.

  Here, as shown in FIG. 17A, the shape of the irradiation field stop (irradiation field region) does not always face the flat detector 2210. Depending on the imaging means, the part, and the like, FIG. It may be circular as shown in B).

  Also in this case, pixel data is read out by a reading operation by scanning. Therefore, regardless of the inclination and shape of the irradiation field stop, a sub-scanning range that defines a circumscribed rectangle including the entire irradiation field stop shown by the irradiation field stop 2222 in FIG. 17A or the irradiation field stop 2223 in FIG. It is necessary to read in 2217 and the main scanning range 2218.

  In this case, a portion that is not irradiated, that is, a portion that does not include useful image data is also read out and transferred to the outside. Therefore, there is a problem that the transfer time is longer than the required amount of image information and high-speed reading becomes difficult.

  This effect is particularly noticeable in a moving image in which a plurality of images are read out by operating a flat detector in order to observe the movement of a subject.

  Therefore, in the fifth embodiment, in the X-ray flat panel detector that performs reading by scanning, scanning is limited to the range including the entire irradiation field, and the reading range in the main scanning direction is adjusted to the irradiation field range. The data is read and transferred while changing every row. This prevents transfer of pixel data in a useless area.

  FIG. 18 is a block diagram showing a configuration of an X-ray imaging apparatus according to the fifth embodiment of the present invention.

  The X-ray imaging apparatus includes an X-ray tube 1, an X-ray plane detector 3, an input interface (I / F) 4 that receives digital data output from the X-ray plane detector 3 for the subject 2, a writing control device 5, An image memory 6, an address memory 7, and a controller 8 are provided.

  The connection 31 is a connection for transferring image data from the X-ray flat panel detector 3 to the input I / F 4. The connection 32 is a connection for transferring read address data from the controller 8 to the X-ray flat panel detector 3. Further, the connection 32 is used to transmit a command for controlling the operation of the X-ray flat panel detector 3 or to transmit the state of the X-ray flat panel detector 3 to the controller 8.

  The controller 8 includes a computer that controls the entire X-ray imaging apparatus and performs image analysis. For example, the controller 8 may be configured by the hardware of FIG. 2 of the first embodiment. The address memory 7 manages addresses in the readout row for the X-ray flat panel detector 3 and includes a start address memory and an end address memory.

  The writing control device 5 controls the writing of data into the image memory 6 at a position corresponding to the value of each address memory in the address memory 7. The image memory 6 stores image data.

  In FIG. 18, an X-ray 1a indicated by a broken line is subjected to an irradiation field stop.

  Next, a detailed configuration of the X-ray flat panel detector 3 will be described with reference to FIG.

  FIG. 19 is a diagram showing a detailed configuration of the X-ray flat panel detector according to the fifth embodiment of the present invention.

  The X-ray flat detector 9 shown in FIG. 19 corresponds to the X-ray flat detector 3 of FIG. The X-ray flat panel detector 9 has N readout lines indicated by broken lines. The X-ray flat detector 9 is configured with an irradiation field region 10 that is tilted with respect to the facing direction.

  In the fifth embodiment, in order to observe the movement of the subject, a plurality of images (frames) are continuously read to form an X-ray moving image.

  In particular, in the fifth embodiment, consecutive frames are read in the following procedure (step).

1) Whole reading In order to confirm the position, shape, and size of the irradiation field region, the whole frame is read out in the first frame, and all image data is stored in the image memory 6.

2) Image analysis The controller 8 reads the first frame in the image memory 6 and analyzes the shape of the irradiation field region. In general, since the pixel value of an irradiation field area that has been irradiated with X-rays is larger than the surrounding area, the irradiation field area can be identified by binarizing with a threshold value of a prescribed pixel value level. Alternatively, if the shape of the irradiation field area is known in advance (eg, quadrangle, octagon, circle, etc.), the binarized irradiation field area is optimally fitted to the known shape to stably define the irradiation field area. It is also possible to do.

3) Irradiation field address extraction for each row The field area subjected to image analysis is analyzed for each readout line. The start address (pixel position) and the end address are recorded in the address memory 7 for each line.

  In FIG. 19, as shown in FIG. 20, the start address of the P line is represented by X1, the end address is X2, the start address of the P + 1 line is represented by X3, and the end address is represented by X4. If there is no irradiation field area in the line, the start address = 0 and the end address = 0 are recorded.

  The expression method of this address is not limited to this, and an expression method of a start point address and a data length is also possible.

4) Address transfer to the X-ray flat panel detector 3 The address is also transmitted to the X-ray flat panel detector 3.

  Here, the internal configuration of the X-ray flat panel detector 3 will be described with reference to FIG.

  FIG. 21 is a block diagram showing an internal configuration of the X-ray flat panel detector according to the fifth embodiment of the present invention.

  In FIG. 21, the address transmitted through the connection line 32 is written to the end address memory 22 and the start address memory 23 in the X-ray flat panel detector 9 through the controller 33 of the flat panel detector unit 9.

5) Shooting / Reading Operation In FIG. 21, the pixel clock generator A25 outputs a high-speed clock signal of about 100 MHz as the clock A. The pixel clock generator B26 outputs a clock signal for performing normal A / D conversion of about 10 MHz as the clock B.

  The multiplexer (MPX) 15 switches the clock signal from the pixel clock generator A25 and the pixel clock generator B26. The output line 30 is connected to the pixel counter 16 and the shift register 14 constituting a part of the main scanning selection control circuit. Here, the main scanning selection control circuit includes a multiplexer 13 and a shift register 14.

  When there is an instruction to start photographing, the controller 33 clears the values of the line counter 21 and the pixel counter 16 to 0 by means not shown. The output of the line counter 21 is connected to the read addresses of the end address memory 22 and the start address memory 23 in order to read the end address and start address in the corresponding line.

  The output K of the end address memory 22 and the output L of the pixel counter 16 are compared with each other by the comparator 34. At a time point equal to the value of the end address, an output pulse of the comparator is obtained and input to the line counter 21. As the value of the line counter 21 advances, the next end address and start address are obtained from the end address memory 22 and the start address memory 23, respectively.

  Therefore, when the end address is 0, that is, when there is no irradiation field on the line, the comparator 34 operates continuously and the line counter 21 is counted up. Further, a count pulse is output from the comparator 34 to the line counter 21. At the same time, a clear signal of the pixel counter 16, a reset input of the flip-flop (F / F) 24, and a clock signal are input to the shift register 20 that constitutes a part of the sub-scanning selection control circuit. Here, the sub-scanning selection control circuit includes a driver 19 and a shift register 20.

  On the other hand, when the end address is not 0, that is, when there is an irradiation field on the line, the output J of the pixel counter 16 is compared with the output I of the start address memory by the comparator 35. When the value of the pixel counter 16 becomes equal to the value of the start address memory, the comparator 35 operates to switch the output of the multiplexer 15 from the pixel clock generator A25 to the pixel clock generator B26.

  When the clock signal becomes clock B, the shift register 14 operates at a normal A / D conversion speed, and the output switching speed of the multiplexer (MPX) 13 is set to a speed at which the A / D converter 12 can operate. Thus, normal pixel data is output. At the same time, a signal is input to the set signal of the flip-flop 24, and the Enable signal that is the output signal of the flip-flop 24 becomes valid. As a result, the output of the output interface (I / F) 11 becomes valid, and pixel data is output through the connection 31.

  FIG. 22 is a timing chart of the Enable signal on the signal line 29 and the pixel clock on the output line 30 in FIG. The pixel clock A, which is a high-speed clock, is used before the start address, and the pixel clock B, which is a normal clock, is used after the start address, and the Enable signal changes accordingly.

  Therefore, in FIG. 21, for example, in the arrow range 27, the operation is performed with a very fast clock signal, and only the logic circuit system operates without reading the pixel data. On the other hand, in the section 28 in the irradiation field, the normal clock operation is performed to read out the pixel data and output to the outside. When the section 28 ends (end address memory value), the next line is read.

  Thus, by controlling the reading of useless portions for each line, the transfer time of image data as shown in FIG. 23 is reduced.

  In FIG. 23A, the horizontal axis represents time, and the vertical axis represents lines. The transfer time corresponding to time × line in total takes time, and image data is transferred over the time corresponding to the filled area. On the other hand, FIG. 23B shows the transfer time according to the configuration of the fifth embodiment. The transfer time is very high up to the start address and no unnecessary part is transferred. It is greatly reduced. In this case, the transfer time is about half that of the configuration of FIG.

  FIG. 24 shows the state of the image memory 6 in FIG. 18 that receives image data.

  In FIG. 24, reference numeral 40 denotes the entire memory area for one image. Prior to receiving image data, the image memory writes a uniform numerical value (for example, 0) as a whole. When the image data is transferred line by line, the writing control device 5 in FIG. 18 writes the image data to the corresponding memory address according to the contents of the address memory 7, It is formed as 41 in FIG.

  As described above, according to the fifth embodiment, the sub-scanning direction is limited to the range including the entire irradiation field, and the reading range in the main scanning direction is changed for each row in accordance with the irradiation field region. By reading and transferring, it is possible to prevent transfer of pixel data in a useless area. Thereby, the total throughput of the entire apparatus can be improved.

<Embodiment 6>
In FIG. 21, when the main scanning selection control circuit is configured not by the shift register 14 but by a decoder that can input an arbitrary numerical value from the outside and appropriately select the corresponding signal, the main scanning selection can be randomly accessed. Become.

  In the case of such a configuration, as in the fifth embodiment, it is possible to read out only the effective image data without transferring the unnecessary portion of the effective image data at a high speed.

<Embodiment 7>
In the first embodiment, the irradiation field area is detected and image data of only the irradiation field area is read out, but the present invention is not limited to this. That is, generally, the range in which image data is read is not limited to the irradiation field region. Therefore, it is also possible to read out image data in an arbitrary range (area) regardless of the irradiation field area by a reading range specifying means (not shown) on the controller 8 in FIG.

  The reading range in this case is not limited to a rectangular range that faces the X-ray flat panel detector 3, and an arbitrary shape can be used. The address data can be recorded in the address memory 7 for each line corresponding to the reading range designated by the controller 8 and the image data can be read out by the same operation as in the sixth embodiment.

  Although the embodiment has been described in detail above, the present invention can take an embodiment as a system, apparatus, method, program, storage medium, or the like. Specifically, the present invention may be applied to a system composed of a plurality of devices, or may be applied to an apparatus composed of a single device.

  In the present invention, a software program (in the embodiment, a program corresponding to the flowchart shown in the drawing) that realizes the functions of the above-described embodiments is directly or remotely supplied to a system or apparatus. In addition, this includes a case where the system or the computer of the apparatus is also achieved by reading and executing the supplied program code.

  Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. In other words, the present invention includes a computer program itself for realizing the functional processing of the present invention.

  In that case, as long as it has the function of a program, it may be in the form of object code, a program executed by an interpreter, script data supplied to the OS, or the like.

  Examples of the recording medium for supplying the program include a floppy (registered trademark) disk, a hard disk, and an optical disk. Further, as a recording medium, magneto-optical disk, MO, CD-ROM, CD-R, CD-RW, magnetic tape, nonvolatile memory card, ROM, DVD (DVD-ROM, DVD-R), etc. is there.

  As another program supply method, a browser on a client computer is used to connect to an Internet home page. Then, the computer program itself of the present invention or a compressed file including an automatic installation function can be downloaded from a homepage of the connection destination to a recording medium such as a hard disk. It can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading each file from a different homepage. That is, a WWW server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer is also included in the present invention.

  In addition, the program of the present invention is encrypted, stored in a storage medium such as a CD-ROM, distributed to users, and key information for decryption is downloaded from a homepage via the Internet to users who have cleared predetermined conditions. Let It is also possible to execute the encrypted program by using the key information and install the program on a computer.

  Further, the functions of the above-described embodiments are realized by the computer executing the read program. Further, based on the instructions of the program, an OS or the like running on the computer performs part or all of the actual processing, and the functions of the above-described embodiments can be realized by the processing.

  Further, the program read from the recording medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Thereafter, the CPU of the function expansion board or function expansion unit performs part or all of the actual processing based on the instructions of the program, and the functions of the above-described embodiments are realized by the processing.

It is a figure which shows the structure of the X-ray fluoroscopic apparatus of this invention. It is a figure which shows the hardware constitutions for implement | achieving the X-ray fluoroscopic imaging apparatus of this invention. It is a flowchart which shows operation | movement of the image imaging device of Embodiment 1 of this invention. It is a figure which shows the example of the execution method of the rough reading of Embodiment 1 of this invention. It is a figure which shows the example of the image size conversion process of Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the image imaging device of Embodiment 2 of this invention. It is a figure for demonstrating the frame process of Embodiment 2 of this invention. It is a flowchart which shows operation | movement of the image imaging device of Embodiment 3 of this invention. It is a figure for demonstrating the irradiation field confirmation process of Embodiment 3 of this invention. It is a figure for demonstrating Embodiment 4 of this invention. It is a figure for demonstrating the example of X-ray imaging. It is a figure for demonstrating the flat detector which concerns on this invention, and its reading operation | movement. It is a figure for demonstrating the component of the flat detector which concerns on this invention. It is a figure for demonstrating each timing for the signal state of each selection control signal 1-N of the subscanning selection control circuit based on this invention. It is a figure for demonstrating the X-ray imaging which concerns on this invention. It is a figure which shows the detail of the plane detector which concerns on this invention, and its periphery structure. It is a figure for demonstrating an example of the shape of the irradiation field area | region which concerns on this invention. It is a block diagram which shows the structure of the X-ray imaging apparatus of Embodiment 5 of this invention. It is a figure which shows the detailed structure of the X-ray flat panel detector of Embodiment 5 of this invention. It is a figure which shows the memory structural example of the address memory of Embodiment 5 of this invention. It is a block diagram which shows the internal structure of the X-ray flat panel detector of Embodiment 5 of this invention. It is a figure which shows the timing chart of the pixel clock of the X-ray flat panel detector of Embodiment 5 of this invention. It is a figure for demonstrating the read time of Embodiment 5 of this invention. It is a figure which shows the structure of the image memory of Embodiment 5 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Reading mode control part 102 Image reading part 103 Irradiation field recognition process part 104 Image processing part for display 105 Image display part 201 Control PC
202 Planar detector 203 CPU
204 RAM
205 ROM
206 Input unit 207 Display unit (operation monitor)
208 storage unit 209 display unit (real-time monitor)
210 Image processing unit 211 HDD
212 NIC
221 Bus 222 Optical fiber

Claims (7)

An image processing apparatus that reads out pixel data from a detector that detects radiation emitted from a radiation source and executes image processing,
Control means for controlling switching between a full area readout mode for reading out pixel data of the whole detection area of the detector and a partial area readout mode for reading out pixel data of the partial area of the detection area based on a designated cycle. When,
Reading means for reading out pixel data of the detection area of the detector based on a reading mode specified by the control means;
Recognizing means for recognizing an irradiation field area of the radiation with respect to the detector based on an image composed of pixel data read by the reading means in the whole area reading mode;
Generating means for generating a display image corresponding to the irradiation field area recognized by the recognition means,
When the all area read mode is specified,
The reading means reads out pixel data by thinning out a part of the pixel data group to be read from the detector for one frame,
It said generating means, by resolution conversion irradiation Noga image corresponding to the radiation area, the image processing apparatus and generates the irradiation field image that is the resolution conversion as the display image. The image processing apparatus according to claim 1, further comprising a storage unit that stores irradiation field region information related to the irradiation field region recognized by the recognition unit in order to update the partial region in the partial region reading mode. . When the partial region readout mode is designated, the readout unit reads out pixel data of the partial detection region of the detector based on irradiation field region information stored in the storage unit. The image processing apparatus according to claim 2. In the partial area reading mode, the first irradiation field region extracted by the reading means reading based on the irradiation field region information stored in the storage means, and then the recognition by the recognition means is executed for recognition. The image processing apparatus according to claim 2, further comprising: a correction unit that corrects the irradiation field region information stored in the storage unit based on the second irradiation field region that is performed. Setting means for setting a feedback area including the center of the irradiation field area recognized by the recognition means;
Adjusting means for adjusting a set value relating to radiation of the radiation source based on pixel data detected in a detection area of the detector corresponding to a feedback area set by the setting means; The image processing apparatus according to claim 1. A control method for an image processing apparatus that reads out pixel data from a detector that detects radiation emitted from a radiation source and executes image processing,
Based on a specified cycle, the control means switches between an entire region reading mode for reading pixel data of the entire detection region of the detector and a partial region reading mode for reading pixel data of the partial region of the detection region. A control process to control;
A reading step for reading out pixel data of a detection region of the detector based on a reading mode specified by the control step;
A recognition step of recognizing an irradiation field region of the radiation with respect to the detector based on an image composed of pixel data read out in the reading step in the full-region reading mode;
A generating step of generating a display image corresponding to the irradiation field area recognized in the recognition step;
When the all area read mode is specified,
The reading step reads out pixel data by thinning out a part of a pixel data group to be read for one frame from the detector,
The generating step, by resolution conversion irradiation Noga image corresponding to the exposure field region, control of the image processing apparatus and generates the irradiation field image that is the resolution conversion as the display image Method. Computer
An image processing apparatus that reads out pixel data from a detector that detects radiation emitted from a radiation source and executes image processing,
Control means for controlling switching between a full area readout mode for reading out pixel data of the whole detection area of the detector and a partial area readout mode for reading out pixel data of the partial area of the detection area based on a designated cycle. When,
Reading means for reading out pixel data of the detection area of the detector based on a reading mode specified by the control means;
Recognizing means for recognizing an irradiation field area of the radiation with respect to the detector based on an image composed of pixel data read by the reading means in the whole area reading mode;
To function as a generating unit that generates a display image corresponding to the irradiation field recognized by said recognition means,
When the all area read mode is specified,
The reading means reads out pixel data by thinning out a part of the pixel data group to be read from the detector for one frame,
It said generating means, by resolution conversion irradiation Noga image corresponding to the radiation area, the computer program characterized by generating the irradiation field image that is the resolution conversion as the display image.

Images