JP5761926B2 - Image processing apparatus, image processing method, program, imaging system, and radiation imaging system - Google Patents

Description

  The present invention relates to an image processing device that reduces specific image information included in an image obtained by an imaging device, an image processing method, a program for performing the image processing, an imaging system that performs the image processing, and a radiation imaging system. .

  In photographing a subject, it should normally be avoided to place a structure different from the subject between the subject and the sensor. This is because the image of the structure is superimposed on the image of the subject and the image information of the subject is lost. However, there is a case where such a structure needs to be arranged due to the special feature of photographing and the restriction of the apparatus.

  For example, in radiography, the sensor unit detects radiation that has passed through the subject, but part of the radiation is scattered inside the subject. Noise is generated in the radiation image when the sensor unit receives the scattered radiation. In order to remove this, a structure called a grid in which members having a high X-ray transmittance and members having a high X-ray absorption rate are alternately arranged is arranged between the subject and the sensor unit. In this case, although noise due to scattered radiation is reduced, the grid image is superimposed on the subject image. As another example, a sensor used for radiography needs to be in close contact with the subject as much as possible, but the strength is not high. Therefore, a structure such as a lattice shape or a honeycomb shape is provided on the radiation incident surface of the housing to strengthen the structure of the housing. In this case, although the structure is strengthened, a lattice-like or honeycomb-like pattern is superimposed as noise on the radiation image.

  As described above, when a structure is arranged to give a specific function to the photographing apparatus or due to physical restrictions of the apparatus, an image of the structure may be superimposed on a part of the image. is there. For this reason, it is necessary to identify and eliminate or reduce the images resulting from these structures from the images.

  As a technique for identifying and reducing an image of a specific structure appearing in such an image, Patent Document 1 discloses a technique for identifying and subtracting a grid image from the image using grid pitch information and rotation state information. Has been. Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique for generating a grid stripe component model by analyzing an image and subtracting it from a radiation image. Patent Document 3 discloses a technique for analyzing an image and modeling a fundamental frequency component caused by a grid and a harmonic component of a predetermined multiple of the fundamental frequency component.

JP-A-10-262916 JP 2002-330344 A JP 2006-122695 A

  When the grid pitch information is used, the processing load is reduced compared to the case of analyzing the image. However, when the positional relationship between the grid and the radiation source is shifted, the grid image is blurred, so the grid pitch information In some cases, the grid image cannot be accurately identified. On the other hand, in the case of analyzing an image, the identification accuracy is higher than that in the case of identifying from the pitch information of the grid, but there is a problem that the processing load increases.

Therefore, an image processing apparatus according to an embodiment of the present invention is an image processing apparatus that processes an image obtained from a sensor unit by arranging and photographing a structure between the sensor unit and a subject. obtained from part to photograph an image obtaining unit for obtaining an image which the image is superimposed in the structure, and disposed obtaining means for obtaining information indicating the positional relationship between the sensor unit and the structure, the image Reduction means for reducing the image in accordance with shooting conditions, and the reduction means is based on information indicating an arrangement relationship acquired by the arrangement acquisition means when the image is a moving image. The image in the moving image is reduced .

  Since the present invention having such a configuration can perform image reduction processing by changing the image identification method according to the shooting conditions, there is a need for shooting when priority is given to fineness or processing speed. Accordingly, an image with a reduced image of the structure can be provided.

1 is a diagram illustrating a configuration of a radiation imaging system 100. FIG. 2 is a diagram illustrating an example of a hardware configuration of an image processing apparatus 102. FIG. It is a figure which shows the outline | summary of the process which reduces the image of a grid. 3 is a flowchart illustrating a processing flow of the image processing apparatus 102. 6 is a flowchart showing a flow of other processing of the image processing apparatus 102. 6 is a flowchart showing a flow of other processing of the image processing apparatus 102. 6 is a flowchart showing a flow of other processing of the image processing apparatus 102. It is a figure which shows the outline | summary of the rotation process of an image. It is a figure which shows the change process of the irradiation field in the sensor part. 6 is a flowchart showing a flow of other processing of the image processing apparatus 102.

  Embodiments of the present invention will be described below with reference to the drawings as appropriate.

  In this embodiment, an example in which the present invention is applied to the radiation imaging system 100 will be described.

  First, the configuration of the radiation imaging system 100 will be described with reference to FIG. The radiation imaging system 100 includes a radiation imaging apparatus 101, an image processing apparatus 102, an operation unit 103, a printer 104, a display device 105, and a server apparatus 106, which can communicate with each other by wired or wireless communication means. Yes. The radiation imaging apparatus 101 captures the subject 108 and obtains a radiation image on which the stripe image of the grid 109 is superimposed. The image processing apparatus 102 performs processing for reducing the fringe image of the grid 109 from the radiation image, outputs the processed image to the outside, and provides it to a doctor or the like.

  The radiation imaging apparatus 101 includes a radiation source 107, a grid 109, a sensor unit 110, a detection unit 111, and a transmission / reception unit 112. The radiation source 107 is an X-ray tube that emits X-rays, for example, and the subject 108 is irradiated with the X-rays. Among them, X-rays transmitted through the subject and scattered X-rays scattered by the subject enter the grid 109. The grid has an X-ray shielding material such as lead and an X-ray transmitting material such as wood, paper, aluminum, or carbon, which are alternately arranged and oriented at an angle so as to converge to the focal point of the X-ray tube. In addition, it has a structure in which they are alternately arranged with a predetermined width. Since the X-rays that are not scattered by the subject travel straight from the focal point of the X-ray tube, they pass through the X-ray transmitting material of the grid 109 and reach the sensor unit 110. On the other hand, X-rays scattered by the subject are captured by the X-ray shielding material and do not reach the sensor unit 110. In this way, the scattered rays are removed by regulating the incident angle of the X-rays to the sensor unit 110. The grid 109 is an example of a structure disposed between the subject and the sensor unit in the present invention.

  The sensor unit 110 is an FPD type two-dimensional image sensor in which X-rays are made visible light or light having a wavelength close to this, and a phosphor and an image sensor that receives light from the phosphor and converts it into an electrical signal. is there. X-rays that have passed through the subject reach the sensor unit 110, are converted into visible light by the phosphor, and visible light is converted into an electrical signal by the imaging device, so that a radiographic image of the subject can be obtained. The sensor unit 110 can be driven to generate a moving image and a still image.

  Here, since the X-ray shielding material of the grid 109 does not substantially transmit X-rays, an image of the X-ray shielding material of the grid 109 can be formed in the radiation image formed by the sensor unit 110. Although this grid image depends on the structure of the grid 109, it is generally a substantially parallel stripe pattern, and this stripe is superimposed on the radiation image. Due to the stripe pattern, the image of the subject becomes unclear, and moire due to the stripe occurs, making it difficult to observe the image.

  The detection unit 111 detects the relative arrangement state of the grid 109 in the radiation imaging apparatus 101. The relative arrangement state is a positional relationship with the sensor unit 110 or the radiation source. When this changes, the grid image superimposed on the radiographic image also changes. As a result, the detection unit 111 can detect a change in the grid image superimposed on the image. In the present embodiment, the detection unit 111 mechanically or electromagnetically detects the amount of change when the sensor unit 110 rotates or translates. The change is also detected when the sensor unit 110 is installed or removed. The relative displacement between the grid 109 and the sensor unit 110 is detected. However, the movement of the grid 109 and the radiation source 107 may be detected. When the detection unit 111 detects the arrangement state, the detection unit 111 generates information indicating the arrangement state, and this is sent to the transmission / reception unit 112. Generation of information indicating the arrangement state is performed according to a change in the arrangement state. It may be generated at a predetermined interval.

  The transmission / reception unit 112 transmits image data formed by the sensor unit 110 and information indicating the arrangement state generated by the detection unit 111, and receives the imaging conditions transmitted from the imaging instruction unit 119 of the image processing apparatus 102. . The transmission / reception unit 112 enables communication between the radiation imaging apparatus 101 and the image processing apparatus 102. Transmission of images and information is appropriately performed according to image formation and information generation. The received imaging conditions are set in the sensor unit 110 or the radiation source 107 and the like, and the sensor unit 110 and the radiation source 107 perform driving suitable for the imaging conditions.

  Next, the configuration of the image processing apparatus 102 will be described. The image processing apparatus 102 includes an acquisition unit 113, an image specification unit 114, an analysis unit 115, an image reduction unit 116, an output control unit 117, a setting unit 118, a shooting instruction unit 119, and a storage unit 120.

  The acquisition unit 113 acquires information indicating an image and an arrangement state sent by the radiation imaging apparatus 101. Therefore, the acquisition unit 113 functions as an image acquisition unit and also functions as an arrangement acquisition unit. These data acquired by the acquisition unit 113 are stored in the storage unit 120 and sent to the image specifying unit 114. The image acquired by the acquisition unit 113 includes a subject image on which an image of the grid 109 is superimposed.

  The image specifying unit 114 performs processing for specifying the image of the grid 109 superimposed on the image acquired by the acquiring unit 113. The image specifying unit 114 can execute the following plurality of methods for specifying an image.

  One method is to use information indicating the arrangement state of the detection unit 111. From the arrangement state of the grid 109 acquired by the acquisition unit 113, the direction of the grid stripes is specified. Further, the image specifying unit 114 acquires the pitch of the grid 109 as information indicating the shape of the grid 109 as a structure. The grid pitch refers to the length of the repeating unit of the X-ray shielding member and the X-ray transmission member. When a grid is installed on the photographing stand, the pitch of the grid is set in advance as a photographing condition. When the sensor unit 110 is a portable cassette and the grid can be stored in the cassette, the pitch of the grid may be acquired from the detection mechanism of the grid type in the sensor unit 110. Although this grid image identification method is advantageous in terms of processing time, it is necessary to provide a detection unit, and if there is a shift between the focal point of the radiation source 107 and the focal point of the grid 109, blurring occurs. Therefore, the image may not be reduced.

  Another method is a method using information of the grid 109 set by the setting unit 118. In accordance with an input from the operation unit 103, the setting unit 118 sets information on the grid 109 as a shooting condition, and identifies an image of the grid based on the set information. Although the processing time is reduced as in the above method, it is necessary for the user to input information of the grid 109 via the operation unit 103, and a case where a setting error occurs is higher than other methods.

  Another method is a method of specifying the image of the grid 109 by the analysis unit 115 analyzing the image, as in a known method disclosed in Patent Document 2. Since the grid has a predetermined spatial frequency in the image, there is a method of identifying the image by analyzing the image of the grid from the image. A special detection mechanism and user operation are not required, and the processing takes time in consideration of blurring of the grid image.

  Another method is a method in which the analysis unit 115 identifies an image of the grid 109 by analyzing the image, as in a known method disclosed in Patent Document 3, but the basic method depends on the pitch of the grid. This is a method for specifying a grid image in consideration of a harmonic component of n times the frequency. Although the image due to the grid can be reduced with high accuracy, it takes a lot of processing time.

  As another method, there is a method of acquiring a pair of a white image acquired with the grid 109 installed and a white image acquired without installing the grid 109, and specifying the grid image from this difference. Grid images obtained from these white images are stored in the storage unit 120 and used for the grid reduction processing. The white image is an image obtained by irradiating the sensor unit 110 with radiation without a subject, and is an image showing a difference in characteristics of each pixel of the sensor unit 110. There is an advantage that the processing time at the time of photographing can be shortened, which can be acquired in advance, but a large amount of memory is required because a pair of white images must be prepared for each grid.

  Since the grid image identification method described above is not good at processing load and accuracy, the image identification unit 114 uses a combination or selection of these according to the shooting conditions. The imaging conditions here include the driving conditions of the radiation source 107 and the sensor unit 110 of the radiation imaging apparatus 101 and the part information of the subject 108 to be imaged. As a result, it is possible to perform a grid image identification process in accordance with the purpose of photographing. Note that the grid specifying method is not limited to the above example.

  The image reducing unit 116 reduces the grid image specified by the image specifying unit 114. The reduction process is realized by a method such as interpolating the position of the specified grid image with surrounding pixels. In addition, the grid stripe reduction process may be performed by a known method.

  The output control unit 117 performs control to output a radiation image. Possible output destinations include a printer 104 for forming an image on a film or the like, a display device 105, a server device 106 for managing image information and patient information in an integrated manner. A process of changing the image format according to each output destination is performed. Note that, when outputting to the display device 105, the output control unit 117 functions as a display control unit.

  The setting unit 118 sets shooting condition information including the arrangement state of the grid 109 input by the user via the operation unit 103. The set shooting conditions are stored in the storage unit 120.

  The imaging instruction unit 119 transmits the imaging conditions set by the setting unit 118 to the radiation imaging apparatus 101. In this respect, the image processing apparatus 102 also has a function as a photographing instruction apparatus. An instruction to start exposure from the radiation source 107 is given via an operation unit (not shown). The imaging instruction unit and the acquisition unit 113 described above enable communication between the image processing apparatus 102 and the radiation imaging apparatus 101.

  The storage unit 120 stores information acquired from the radiation imaging apparatus 101 or the operation unit 103, input data necessary for processing by the image processing apparatus 102, and processing result data.

  In addition, the CPU (not shown in FIG. 1) controls each part of the image processing apparatus 102 in an integrated manner. For example, an instruction to store information by the storage unit 120 is performed by the CPU.

  Each part or functional block of the above-described image processing apparatus 102 may be implemented as a circuit, but each of the above-described functions may be executed by causing the CPU 1021 of the electronic computer to execute a software program. FIG. 2 is a diagram illustrating hardware of an electronic computer that functions as the above-described image processing apparatus 102. The image processing apparatus 102 includes a CPU 1021, a RAM 1022, a ROM 1023, an HDD 1024, and an I / F 1025 that enables communication between an external apparatus and the image processing apparatus 102 as hardware. Further, a keyboard 1031, a mouse 1032, and a display 1051 are connected. The ROM 1023 or the HDD 1024 stores a program for realizing the above-described functional blocks or executing the processing shown in FIG. When this program is expanded in the RAM 1022 and executed by the CPU 1021, the hardware and software of the image processing apparatus 102 are combined to realize the above-described functions. For example, the function of the storage unit 120 is realized by the cooperation of the CPU 1021, the HDD 1024, and the program, and the function of the acquisition unit 113 or the photographing instruction unit 119 is realized by the cooperation of the I / F 1025, the CPU 1021, and the program.

  FIG. 3 shows an outline of the grid image reduction processing executed by the above-described image processing apparatus 102 in this embodiment. On the left side of FIG. 3, a subject 108, a grid 109, and a sensor unit 110 are arranged. Photographing is performed in an arrangement state as shown on the left side of FIG. 3, and an image of the subject is formed. This image is an image in which grid stripes are superimposed as shown in FIG. The image processing apparatus 102 acquires the rotation angle of the sensor and the relative angle between the grid 109 and the sensor unit 110 from the imaging apparatus together with this image. In FIG. 3, “sensor rotation 0 °” indicates that the rotation angle of the sensor detected by the detection unit 111 is shifted from the value by 0 ° with respect to the reference, and “grid rotation 90 °” indicates the grid 109 and the sensor unit. 110 shows that the relative rotation angle of 110 is shifted by 90 ° from the reference. The direction of the stripes of the grid is specified from the rotation amount from the reference position of the grid, and the grid image in the image is specified by combining this direction and the pitch information of the grid. Then, as shown on the right side of FIG. 3, an image in which the identified grid image is reduced is created. Such a series of grid image identification processing is performed while changing according to the photographing conditions.

  Next, the flow of processing of the image processing apparatus 102 will be described with reference to the flowchart of FIG. In this embodiment, the image processing apparatus 102 performs a process of switching a grid image specifying method depending on whether an image captured by the radiation imaging apparatus 101 is a moving image or a still image.

  In step S <b> 101, the acquisition unit 113 acquires an image on which a grid image is superimposed in accordance with imaging by the radiation imaging apparatus 101. The acquired image is stored in the storage unit 120 by the CPU 1021 and input to the image specifying unit 114. Imaging is performed by the imaging instruction unit 119 transmitting imaging conditions to the radiation imaging apparatus 101 and exposing the radiation from the radiation source. The shooting conditions are stored in the storage unit 120.

  In step S102, the CPU 1021 determines whether the acquired image is a moving image. This determination is performed with reference to the shooting conditions stored in the storage unit 120. The determination may be made using supplementary information attached to the moving image data or the moving image data itself. If it is determined that the image is a moving image (Yes in step S102), the process proceeds to step S103. In the case of a moving image, since the processing time applied for each frame is shorter than that of a still image, the grid image specifying process is performed with priority on the processing time. Here, giving priority to processing time refers to adopting processing with a relatively short processing time among specific methods that the image processing apparatus 102 can take. Therefore, in the following steps, a grid image is specified using information indicating the arrangement state of the grid 109 detected by the radiation imaging apparatus 101 and grid pitch information. In step S <b> 103, the acquisition unit 113 acquires the arrangement state of the grid 109 from the radiation imaging apparatus 101. The information acquired in advance by the acquisition unit 113 and stored in the storage unit 120 is used to input this information to the image specifying unit 114. In this case, the subject of the acquisition process is the CPU 1021.

  In step S <b> 104, the image specifying unit 114 specifies a grid image based on the acquired information indicating the arrangement state and information indicating the grid pitch obtained from the storage unit 120. In the present embodiment, a process for specifying a grid image from only such information is performed. The grid image is specified as a frequency component necessary for forming the grid image from the grid direction and pitch information. As a result, the grid image superimposed on the image can be specified using the information of the grid 109.

  On the other hand, if it is determined in step S103 that the image is not a moving image (No in step S102), the process proceeds to step S105. In the case of a still image, the processing takes more time than a moving image, and there is a request for a high-definition image. Therefore, the processing prioritizing accuracy is performed contrary to step S103. In step S <b> 105, the analysis unit 115 performs processing for analyzing the image and identifying the image of the grid 109. As a method of obtaining an image of a grid by image analysis, a known technique for creating a grid stripe model described in Patent Document 2 or 3 is used.

  After the grid image is specified in step S104 or S105, in step S106, the image reduction unit 116 creates an image obtained by reducing the specified grid image from the image. In step S107, the output control unit 117 performs control to output this image to the outside.

  As described above, the method for specifying the grid image is changed according to the shooting conditions. The speed and accuracy of the processing performed by the image processing apparatus 102 largely depend on the processing for specifying the grid image performed by the image specifying unit 114, and when taking priority, for example, when priority is given to accuracy or processing speed. It is possible to provide an image according to the request. In addition, since the identification method is changed according to the shooting conditions, grid image reduction processing corresponding to a plurality of different driving can be automatically performed without imposing a burden on the user.

  In addition, when shooting a moving image, by performing a grid image specifying process that prioritizes processing time, it is possible to provide a moving image with a reduced grid image while suppressing the processing time. Further, when taking a still image, by performing a grid elephant specifying process giving priority to accuracy, a still image with a reduced grid image can be provided with higher accuracy.

  [Modification 1] In the above embodiment, the grid image is reduced based on the arrangement state detected by the detection unit 111 for the moving image. However, the present invention is not limited to this, and other methods giving priority to the processing speed are used. It may be adopted. For example, as described in the above embodiment, a correction method using a white image may be adopted, or grid arrangement information set by a user may be used.

  [Modification 2] In relation to the modification 1, the method for the still image may adopt other methods giving priority to the definition or the processing accuracy. In addition, in situations where the accuracy of the grid image identification by image processing is improved according to the processing time, a process for increasing the time required for the image processing according to the processing time allowed for the still image is adopted. Also good.

  [Modification 3] Since the method of analyzing the image and specifying the image of the grid requires processing time, in the case of a moving image, the image specifying unit 114 does not perform the process of analyzing the image, and the detection information of the detection unit 111 and The grid image is identified using the pitch information. On the other hand, in the case of a still image, it is also possible to perform processing for analyzing a captured subject image and specifying a grid image. As a result, it is possible to reduce the grid image giving priority to the processing time in the case of a moving image, and it is possible to reduce the reduction of the grid image with high accuracy in the case of a still image.

  In this embodiment, the grid image is specified based on the arrangement state set via the operation unit for the moving image. Further, it is determined whether or not the arrangement state of the grid 109 detected by the detection unit 111 of the radiation imaging apparatus 101 can be acquired. Furthermore, it is determined whether the information indicating the arrangement state generated by the detection unit 111 matches the arrangement state set via the operation unit. Since the system configuration is the same as that of the first embodiment, the description thereof is omitted.

  A flow of processing executed by the image processing apparatus 102 will be described with reference to the flowchart of FIG. Note that description of steps for performing the same processing as in the first embodiment is omitted.

  In step S <b> 203, the setting unit 118 refers to the imaging condition input via the operation unit 103 and sets the arrangement state of the grid 109. When the setting is not made, a warning to the effect that the setting should be made is displayed on the display unit 105. The set arrangement state of the grid 109 is stored in the storage unit 109 together with information indicating the setting input from the operation unit.

  In step S <b> 204, the CPU 1021 determines whether or not the arrangement state of the grid 109 can be acquired from the radiation imaging apparatus 101. This process is necessary because there is no detection unit 111 that detects the arrangement state of the grid 109 when the radiation imaging apparatus 101 does not have a fixing mechanism for the sensor unit 110. Further, this is a process for preventing a processing error when there is a cause in a point where there is an abnormality in the detection unit 111 or communication. This determination is performed according to the fact that the arrangement state cannot be acquired by the acquisition unit 113 for a certain period from the request for information. When the CPU 1021 determines that the arrangement state can be acquired (Yes in step S204), the process proceeds to step S205, and the acquisition unit 113 acquires the arrangement state. On the other hand, if the CPU 1021 determines that the arrangement state cannot be acquired (No in step S204), the process proceeds to step S207, where the image specifying unit 114 is based on the arrangement state set according to the input via the operation unit. Identify the image.

  In step S206, the CPU 1021 determines whether or not the arrangement state obtained from the operation unit 103 set in step S203 matches the arrangement state obtained from the detection unit 111 acquired in step S205. . If it is determined that they match (Yes in step S206), it is considered that there was no error in the input via the operation unit 103. In this case, the process proceeds to step S207, and the grid image is specified in the set arrangement state. On the other hand, if it is determined that they do not match (No in step S206), it is considered that there was an error in input. In this case, the process proceeds to step S208, and the image specifying unit 114 specifies the grid image based on the arrangement state acquired by the acquiring unit 113.

  As described above, there are many cases where the acquisition unit 113 cannot obtain information indicating the arrangement state from the detection unit 111 due to reasons such as the absence of the grid detection unit 111. In such a case, the image of the grid 109 is specified based on the arrangement state of the grid 109 set in advance by the operation unit 103, and when the information detected by the detection unit 111 cannot be acquired, the user input The information set according to is used. Thereby, the grid image can be specified. In addition, in situations where shooting conditions span multiple items and multiple different shootings are performed in succession, the user may mistakenly set the grid layout. Therefore, the grid image can be appropriately reduced.

  In the present embodiment, the grid specifying method is switched depending on whether the moving image is obtained by cine loop photography or the perspective photography. For still images, in addition to displaying an image before grid reduction, a process for outputting a still image with reduced grid images to the outside is performed. Since the system configuration is the same as that of the first embodiment, the description thereof is omitted.

  A flow of processing executed by the image processing apparatus 102 will be described with reference to the flowchart of FIG. Note that a description of steps that perform the same processing as in the first embodiment will be omitted.

  In step S303, the output control unit 117 causes the display 105 to display the image determined as a still image in step S302. This displays a still image that has not been subjected to grid image reduction processing. In this way, the grid reduction process is omitted, and an image is displayed promptly after photographing, enabling quick confirmation by a diagnostician. Thereafter, an image in which the image of the grid is reduced with high accuracy is created by image analysis in the processing in step S305 and subsequent steps. It is possible to meet the demand for examining the subject image in detail using a still image. In general, it is possible to provide a still image corresponding to the diagnostic process of the diagnostician by providing an image with a reduced grid image with high accuracy for detailed examination while enabling quick image display after imaging. it can.

  In step S304, the CPU 1021 determines whether or not the image determined as the moving image in step S302 is an image obtained by fluoroscopic imaging. Here, the fluoroscopic imaging is an imaging method in which the captured moving image is mainly used for real-time observation and is not recorded thereafter. This is a shooting for positioning and still image shooting timing, or a shooting for observing a relatively easy-to-understand structure, and is a low-definition, small image or shooting with a relatively small dose. On the other hand, cine loop photography is a photography method used mainly for examining the operation of a subject in detail. Since it is used for repeatedly viewing and examining a captured moving image after shooting, it is a shooting method for obtaining a relatively high-definition moving image.

  If it is determined that fluoroscopic imaging is performed, it is considered that a moving image is used in parallel with the imaging at the time of imaging. Therefore, the processing time is prioritized and the process proceeds to step S306, and the arrangement state of the grid 109 detected by the detection unit 111 The grid image is detected based on the above. On the other hand, in the case of cine instead of fluoroscopy, importance is placed on the use after shooting. Therefore, after moving image shooting ends, the process proceeds to step S305, and the image specifying unit 114 specifies a grid image from the image. In this manner, the grid image specifying method is changed in accordance with the difference in photographing conditions for whether the same moving image is a fluoroscopic image or a cine image. Thereby, the grid image reduction process according to the request | requirement of each image can be performed.

  [Modification 1] In step S303, the still image displayed on the display unit 105 is an image that does not reduce the grid image. However, the grid image specifying process may be performed with priority given to the processing time.

  In this embodiment, the detection unit 111 notifies the image processing apparatus 102 that the arrangement state of the grid 109 has changed, and the image specifying unit 114 stores the grid stored in the storage unit 120 in accordance with the notified change. Update the image information. Since the system configuration is the same as that of the first embodiment, the description thereof is omitted.

  A flow of processing executed by the image processing apparatus 102 will be described with reference to the flowchart of FIG. Note that description of steps for performing the same processing as in the first embodiment is omitted.

  It is assumed that the model of the grid image has already been specified and stored in the storage unit 120 before step S401. In step S <b> 401, the acquisition unit 113 acquires change information on the arrangement state of the grid 109 from the radiation imaging apparatus 101.

  In step S <b> 404, when the captured image is a moving image, a grid image model is newly created based on the acquired arrangement state and stored in the storage unit 120 to update the image of the grid 109. Here, the grid image is updated by a method in which accuracy is prioritized.

  By such processing, the grid image superimposed on the moving image can be reduced by repeatedly using this model stored in the storage unit 120 until the next change information of the arrangement state is acquired. In particular, if a grid image model is created by acquiring the change information of the arrangement state in a moving image, the grid reduction processing is performed for each subsequent frame image of the moving image using a highly accurate grid image model. It can be carried out. Therefore, the creation of the grid image model is not completed for the first predetermined number of frame images, and the grid image is not reduced. However, when the model creation is completed, the grid image is accurately obtained for moving images acquired thereafter. Image can be reduced.

  [Modification 1] In the case of a moving image, a predetermined number of frame images are analyzed by the analysis unit 115 to identify a grid image, and the specified grid image reduction processing is executed for the other frame images. It is good as well. In this case, after the image analysis is completed, the grid image can be accurately reduced from each frame of the moving image. This is effective when the shooting period is relatively long.

  In the present embodiment, the rotation amount of the sensor unit 110 detected by the detection unit 111 is detected, the image is rotated and an image is output in a direction that is easy to diagnose, and the irradiation of the sensor unit 110 is performed according to the rotation amount of the sensor. Change the field or readout range. Since the system configuration is the same as that of the first embodiment, the description thereof is omitted.

  The outline of the image rotation process will be described with reference to FIG. FIG. 8A shows a reference state in which image rotation is not necessary. In the case of FIG. 8A, image rotation and irradiation field change processing are not performed, and the contents of the grid image reduction processing are the same as those in FIG. On the other hand, in FIG. 8B, the sensor is rotated by 90 ° with respect to the state shown in FIG. 8A, and the relative rotation of the grid with respect to the sensor is different by 90 °. The deviation is 0 °. In such a case, the image data acquired by the acquisition unit 113 from the sensor is in a state of being rotated by 90 ° with respect to the normal display position as shown in the lower middle part of FIG. In such a case, the image is rotated and output as an image as shown in the upper right part of FIG. As described above, the direction of the grid stripe and the rotation of the image are executed based on the common information.

  The outline of the irradiation field changing process will be described with reference to FIG. The rectangle shown by connecting the points P1, P2, P3, and P4 in FIG. 9 indicates the irradiation field irradiated with radiation. Signals from areas other than the irradiation field are not used for image formation, and signals within the irradiation field are used for formation of the subject image. Since the irradiation field region is set as a range in the sensor unit 110, the region having the charge used for forming the subject image in the sensor unit 110 changes according to the rotation. Therefore, it is necessary to acquire an area of the sensor unit 110 that extracts a signal as a subject image.

  By detecting the rotation amount of the sensor and the relative rotation amount between the grid and the sensor, the reading range specifying process can be executed together with the image rotation process and the grid stripe direction specifying process. For example, it is assumed that the irradiation field is a rectangular region defined by P1 to P4 in a state where the sensor unit 110 is arranged as shown in the upper part of FIG. Under this situation, when the sensor unit 110 is rotated 90 ° to be changed to the arrangement shown in the lower part of FIG. 9, the irradiation field is defined as a rectangular area defined by P1 ′ to P4 ′ in the lower part of FIG. Change to

  A flow of the above-described processing executed by the image processing apparatus 102 will be described according to the flowchart of FIG. Note that description of steps for performing the same processing as in the first embodiment is omitted.

  In step S <b> 501, the image processing apparatus 102 acquires shooting condition information including the rotation amount of the sensor unit 110. This information may be acquired by the acquisition unit 113 from the radiation imaging apparatus 101 or may use the imaging conditions stored in the storage unit 120.

  In step S <b> 502, the CPU 1021 sets a sensor reading range in the coordinate system of the sensor unit 110 based on the rotation state of the sensor unit 110.

  In step S503, the radiographic apparatus 101 captures the subject 108.

  An image with reduced grid stripes is created from the images taken up to step S508. In step S509, the output control unit 117 rotates the image 105 so that the image can be easily viewed when displayed on the display unit 105. For example, if the image is an image of a lung field, the display 105 displays the neck so that the neck is on the top and the abdomen is on the bottom.

  As described above, the rotation state of the sensor and the relative rotation information of the grid can be detected, and the irradiation field can be changed, the image can be rotated, and the grid image can be specified based on this information. When performing a plurality of photographings with one sensor unit, it is necessary to rotate the sensor unit or change the gantry between the photographings according to the photographing conditions and parts. Under such circumstances, by acquiring the rotation information of the sensor and the relative rotation information of the grid, it is possible to appropriately perform image rotation, grid image specification, and irradiation field setting. In addition, by providing a detection unit for detecting the rotation state of the sensor and the relative rotation information of the grid in the gantry or the like, manual input by the user is unnecessary.

  [Modification 1] In the above-described embodiment, the process of reducing the image of the grid after rotating the image is shown. However, the present invention is not limited to this, and the process of reducing the image of the grid after rotating the image may be performed. . By doing in this way, when the accuracy of the grid image specifying process by the image specifying unit 114 depends on the direction of the grid image, the image specifying process and the reducing process can be stably performed.

  [Modification 2] Let us consider a case where an image processing algorithm is adopted that can specify and reduce a grid image only when the rotation of the grid from the reference position is n times 90 °. In such a case, when the rotation amount is other than n times 90 °, the grid image specifying process and the reduction process may not be performed.

[Other Examples]
In the above-described embodiment, the process of reducing the image of the grid from the radiation image has been described. However, the present invention can also be applied to a structure other than the grid 109 as long as the image is superimposed on the image. For example, in a radiation detector, a cover may be provided on a radiation incident surface, and a lattice-like or honeycomb-like structure may be provided on a surface opposite to the radiation incident surface of the cover in order to increase the strength of the cover. It is conceivable that a lattice-like or honeycomb-like pattern is superimposed on the image due to this structure. The present invention can also be applied to processing for reducing this image. In addition, it is possible to use the present invention for a process of reducing the image in the case where a structure is arranged to give a specific function to the photographing apparatus or due to physical restrictions of the apparatus. .

  Moreover, although the example which applied this invention to the radiography system was shown in the above-mentioned embodiment, it is not restricted to this. For example, the present invention may be applied to a long image obtained by pasting together images taken by other photographing devices, such as an image obtained by an image sensor that receives visible light reflected or scattered by a subject. . Since it is considered that the system other than the radiographic system has the same problem as the above-described problem, the present invention is significant in the system other than the radiographic system.

  Also, even if the processing performed in the image processing device is distributed by multiple devices and realized as an image processing system, the processing combined as one functional block is realized by distributing it by multiple circuits or functional blocks. May be. Further, the present invention may be realized by the photographing apparatus by incorporating the functions of the image processing apparatus and the display device in the above-described embodiment into the photographing apparatus or the detector.

  The present invention can also be realized by cooperation of hardware and software of an electronic computer. For this purpose, by executing the program code read out by the electronic computer, an operating system (OS) or the like operating on the electronic computer performs part or all of the actual processing. The case where the function is realized is also included. Further, a plurality of CPUs may be included in the computer, and in this case, the present invention may be realized by being distributed by a plurality of CPUs. In this case, the program code read from the recording medium itself realizes the functions of the above-described embodiments, and the recording medium recording the program or the program code constitutes the present invention.

  Further, the program code read from the recording medium is written in a memory in the function expansion card or function expansion unit attached to the computer, and the arithmetic unit in the expansion card or the expansion unit performs part or all of the actual processing. This includes the case where the functions of the embodiment are realized. In this case, the present invention is realized by a circuit implemented by hardware and a function realized by cooperation of software and hardware.

  The above embodiment of the present invention is a preferred example according to the present invention, and the present invention is not limited to this.

DESCRIPTION OF SYMBOLS 100 Radiography system 101 Radiography apparatus 102 Image processing apparatus 109 Grid 110 Sensor part 113 Acquisition part 114 Image specific part 115 Analysis part 116 Image reduction part 117 Output control part 118 Setting part

Claims (38)

An image processing apparatus for processing an image obtained from a sensor unit by arranging and photographing a structure between the sensor unit and a subject,
Image acquisition means for acquiring an image obtained by superimposing an image of the structure obtained from the sensor unit;
An arrangement acquisition unit that acquires information indicating an arrangement relationship between the sensor unit and the structure, and a reduction unit that reduces the image according to an imaging condition for imaging the image;
When the image is a moving image, the reduction unit reduces the image in the moving image based on information indicating the arrangement relationship acquired by the arrangement acquisition unit.   The image processing apparatus according to claim 1, wherein when the image is a still image, the reduction unit reduces the image based on a result of analyzing the still image.   The image processing apparatus according to claim 1, further comprising a specifying unit that specifies the image by a method according to a shooting condition for shooting the image.   The image processing according to claim 3, wherein when the image is a moving image, the specifying unit specifies the image based on information indicating an arrangement relationship acquired by the arrangement acquisition unit. apparatus.   5. The image processing apparatus according to claim 3, wherein when the image is a still image, the specifying unit performs processing for analyzing the image and specifying the image. The specifying means specifies an image of the structure by a method that prioritizes accuracy when the image is a still image, and uses a method that prioritizes processing time when the image is a moving image. The image processing apparatus according to any one of claims 3 to 5, wherein the image is specified. The structure is a grid for removing scattered radiation,
The image processing apparatus according to claim 3, wherein the specifying unit specifies a direction of a striped pattern of the image formed by the structure. A setting unit for setting information indicating an arrangement state of the structure according to an external input to the operation unit;
The said reduction means reduces the said image in the said moving image obtained based on the information which shows the arrangement state set by the said setting means when the said acquisition means cannot acquire the said arrangement state. Item 8. The image processing apparatus according to any one of Items 1 to 7. When the image is a still image, the image display device includes an output control unit that causes the display unit to display an image before the image is reduced by the reduction unit and to transmit the image with the reduced image to the outside. The image processing apparatus according to claim 1, wherein the image processing apparatus is characterized. The specifying unit specifies the image by analyzing a predetermined number of frame images of the moving image when the image of the subject is a moving image;
The image processing apparatus according to claim 1, wherein the reduction unit reduces the identified image with respect to the moving image.   The said arrangement | positioning acquisition means is acquired from the detection part which detects the arrangement | positioning state of at least any one of the said sensor part and the said structure as information which shows the said arrangement | positioning relationship. The image processing apparatus according to item. The arrangement acquisition means receives information indicating a rotation amount from a reference position of the sensor unit in the imaging device as information indicating the arrangement relationship,
The image processing apparatus according to claim 1, wherein the reduction unit reduces the image obtained based on the received information indicating the rotation amount. The image processing apparatus according to claim 12, further comprising display control means for rotating and displaying the image based on the received information indicating the rotation amount. The sensor unit includes a radiation detector that detects radiation emitted from a radiation source and transmitted through the subject,
The image processing apparatus according to claim 1, wherein the structure is a grid for removing scattered radiation. Information indicating the arrangement state of the structure according to an input from the outside to the operation unit, and an arrangement acquisition unit that acquires the arrangement state from a detection unit that detects a relative arrangement state of the structure and the sensor unit And at least one of setting means for setting the image and analysis means for analyzing the image and identifying the image,
15. The method according to claim 1, wherein the method is a method of specifying the image using at least one of the arrangement acquisition unit, the setting unit, and the analysis unit. Image processing apparatus. The image processing apparatus according to claim 1, wherein the specifying unit specifies the image based on information indicating a shape of the structure. An image processing apparatus for processing an image obtained from a sensor unit by arranging and photographing a structure between the sensor unit and a subject,
Image acquisition means for acquiring an image obtained by superimposing an image of the structure obtained from the sensor unit;
Arrangement acquisition means for acquiring information indicating an arrangement relationship between the sensor unit and the structure based on information from a detection unit that detects an arrangement state of at least one of the sensor unit and the structure;
Setting means for setting information indicating an arrangement relationship between the sensor unit and the structure in accordance with an external input to the operation unit;
Reduction means for reducing the image based on information indicating an arrangement relationship between the sensor unit and the structure obtained from either the arrangement acquisition means or the setting means;
An image processing apparatus comprising:   The image processing apparatus according to claim 17, wherein the reduction unit reduces the image based on information set by the setting unit when the information cannot be acquired by the arrangement acquisition unit.   When the arrangement relationship indicated in the information acquired by the arrangement acquisition unit is different from the arrangement relationship indicated in the information set by the setting unit, the reduction unit is information acquired by the arrangement acquisition unit. The image processing apparatus according to claim 17, wherein the image is reduced based on the image. An image processing apparatus for processing an image obtained from a sensor unit by arranging and photographing a structure between the sensor unit and a subject,
Image acquisition means for acquiring an image obtained by superimposing an image of the structure obtained from the sensor unit;
Arrangement acquisition means for acquiring information indicating the arrangement relationship between the sensor unit and the structure, a first process for reducing the image of the structure in the image by a method that prioritizes accuracy, and prioritize processing time A second process for reducing an image of the structure in an image subjected to the first process in a method;
Display control means for displaying on the display unit the image subjected to the first process and the image subjected to the second process;
An image processing apparatus comprising: An image processing apparatus for processing an image obtained from a sensor unit by arranging and photographing a structure between the sensor unit and a subject,
Image acquisition means for acquiring an image obtained by superimposing an image of the structure obtained from the sensor unit;
Arrangement acquisition means for acquiring information indicating the arrangement relationship between the sensor unit and the structure, information indicating the arrangement relationship acquired by the arrangement acquisition means, and the structure is arranged without a subject. A first process for reducing the image in the image based on at least one of a white image obtained by irradiating the sensor unit with uniform radiation or visible light in a state, and a result of analyzing the image A second process for reducing the image based on:
Display control means for displaying on the display unit the image subjected to the first process and the image subjected to the second process;
An image processing apparatus comprising:   The display control means displays the image subjected to the second process on the display unit after displaying the image subjected to the first process. Image processing apparatus. An image processing apparatus that processes a moving image obtained from a sensor unit by arranging and shooting a structure between the sensor unit and a subject,
Image obtaining means for obtaining a moving image obtained by superimposing an image of the structure obtained from the sensor unit;
Arrangement acquisition means for acquiring information indicating an arrangement relationship between the sensor unit and the structure, and whether the moving image is a moving image obtained by X-ray fluoroscopy or a moving image obtained by cine loop imaging In response, a reduction unit that performs processing for reducing the image from the moving image in a different manner, and a display control unit that displays the moving image with the image reduced by the reduction unit on a display unit,
An image processing apparatus comprising: An image processing apparatus that processes a moving image obtained from a sensor unit by arranging and shooting a structure between the sensor unit and a subject,
Image obtaining means for obtaining a moving image obtained by superimposing an image of the structure obtained from the sensor unit;
Arrangement acquisition means for acquiring information indicating an arrangement relationship between the sensor unit and the structure, and reduction means for reducing the image in accordance with imaging conditions for imaging the moving image;
Display control means for displaying the moving image on a display unit by the reduction means, and the reduction means, when the moving image is a moving image obtained by X-ray fluoroscopy, the arrangement acquisition means The moving image is reduced based on the analysis result of the moving image when the image in the moving image is reduced based on the information indicating the arrangement relationship acquired by the above, and the moving image is not a moving image obtained by X-ray fluoroscopy. An image processing apparatus for reducing the image in an image.   24. The image processing apparatus according to claim 23, wherein when the moving image is a moving image obtained by cine-loop imaging, the image in the moving image is reduced based on an analysis result of the moving image. .   The image processing apparatus according to claim 23 or 24, wherein the moving image displayed on the display unit is not left in the storage unit in the X-ray fluoroscopy.   The image processing apparatus according to any one of claims 23 to 25, wherein in the cine-loop imaging, the moving image displayed on the display unit is left in a storage unit. An image processing apparatus for processing an image obtained from a sensor unit by arranging and photographing a structure between the sensor unit and a subject,
Image acquisition means for acquiring an image obtained by superimposing an image of the structure obtained from the sensor unit;
Arrangement acquisition means for acquiring information indicating an arrangement relationship between the sensor unit and the structure, and reduction means for reducing the image in the image based on information indicating the arrangement relationship between the sensor unit and the structure; Have
The arrangement acquisition means acquires information indicating the arrangement relationship after the change according to the change of the arrangement relationship between the sensor unit and the structure,
The image processing apparatus according to claim 1, wherein the reduction unit reduces the image based on the information when the information indicating the changed arrangement relationship is acquired.   29. The image processing apparatus according to claim 28, further comprising a range changing unit that changes a reading range of the sensor unit in response to acquisition of information indicating the changed arrangement relationship.   30. The irradiation field changing means according to claim 28, further comprising irradiation field changing means for changing an irradiation field of the sensor unit by a radiation generator in response to acquisition of information indicating the changed arrangement relationship. Image processing apparatus. A radiation detector that obtains a radiation image of a subject by receiving radiation emitted from the radiation source and transmitted through the subject;
A grid for removing scattered radiation disposed between the radiation detector and the subject;
Detecting means for detecting a direction of the grid stripes with respect to the radiation detector;
An acquisition means for acquiring a radiation image on which an image of the grid stripes obtained by the radiation detector is superimposed;
Grid stripe reduction means for reducing an image of grid stripes in the radiographic image according to imaging conditions for imaging the radiographic image;
Output means for outputting the radiation image with the image reduced,
When the image is a moving image, the grid stripe reducing unit reduces the image in the moving image based on information indicating an arrangement relationship acquired by the detecting unit.
Radiation imaging system characterized by having the. An image processing apparatus for processing an image obtained from a sensor unit by arranging and photographing a structure between the sensor unit and a subject,
An image obtaining step for obtaining an image obtained by superimposing an image of the structure obtained from the sensor unit;
An arrangement obtaining step for obtaining information indicating an arrangement relationship between the sensor unit and the structure, and a reduction step for reducing the image according to a photographing condition for photographing the image. An image processing method, wherein, when the image is a moving image, the image in the moving image is reduced based on information indicating the arrangement relationship acquired in the arrangement acquisition step. An image processing method for processing an image obtained from a sensor unit by arranging and photographing a structure between the sensor unit and a subject,
An image obtaining step for obtaining an image obtained by superimposing an image of the structure obtained from the sensor unit;
An arrangement acquisition step for acquiring information indicating an arrangement relationship between the sensor unit and the structure based on information from a detection unit that detects an arrangement state of at least one of the sensor unit and the structure;
A setting step for setting information indicating an arrangement relationship between the sensor unit and the structure in response to an external input to the operation unit;
A reduction step of reducing the image based on information indicating an arrangement relationship between the sensor unit and the structure, which is obtained by either the arrangement acquisition step or the setting step. Processing method. An image processing method for processing an image obtained from a sensor unit by arranging and photographing a structure between the sensor unit and a subject,
A step of obtaining an image obtained by superimposing an image of the structure obtained from the sensor unit; a placement obtaining step for obtaining information indicating a placement relationship between the sensor unit and the structure; and the placement obtaining unit. At least one of information indicating the obtained arrangement relationship and a white image obtained by irradiating the sensor unit with uniform radiation or visible light without the subject being interposed and the structure being arranged Performing a first process to reduce the image in the image based on:
Performing a second process of reducing the image in the image based on a result of analyzing the image subjected to the first process;
Displaying an image on which the first processing has been performed and an image on which the second processing has been performed on a display unit;
An image processing method comprising: An image processing method for processing a moving image obtained from a sensor unit by arranging and photographing a structure between the sensor unit and a subject,
An image obtaining step for obtaining an image obtained by superimposing an image of the structure obtained from the sensor unit;
An arrangement acquisition step of acquiring information indicating an arrangement relationship between the sensor unit and the structure, and whether the moving image is a moving image obtained by X-ray fluoroscopy or a moving image obtained by cine loop imaging Accordingly, a reduction step of reducing the image in different ways;
And displaying the moving image in which the image has been reduced in the reduction step on a display unit. An image processing method for processing a moving image obtained from a sensor unit by arranging and photographing a structure between the sensor unit and a subject,
An image obtaining step for obtaining a moving image obtained by superimposing an image of the structure obtained from the sensor unit;
An arrangement acquisition step of acquiring information indicating an arrangement relationship between the sensor unit and the structure, a reduction step of reducing the image by a method according to an imaging condition for capturing the moving image, and the moving image by the reduction means A display control step for displaying an image on a display unit, and in the reduction step, when the moving image is a moving image obtained by X-ray fluoroscopy, the arrangement relationship acquired by the arrangement acquiring unit If the moving image is not a moving image obtained by X-ray fluoroscopy, the image in the moving image is reduced based on the analysis result of the moving image. An image processing method. An image processing method for processing an image obtained from a sensor unit by arranging and photographing a structure between the sensor unit and a subject,
Obtaining an image obtained by superimposing an image of the structure obtained from the sensor unit; obtaining information indicating an arrangement relationship between the sensor unit and the structure;
Reducing the image in the image;
Obtaining information indicating the post-change arrangement relationship in response to the arrangement relationship between the sensor unit and the structure being changed;
Reducing the image based on the information in response to the acquisition of information indicating the post-change arrangement relationship;
An image processing method comprising: Program for executing the image processing method according to the computer in any one of claims 32 to 3 7.