JP2015112432A - Information processing device and control method thereof, radiation image photographing device, and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology of afterimage correction capable of reducing influence on a photographing interval in the case of photographing a plurality of radiation images.SOLUTION: An information processing device for processing a radiation image includes acquisition means for acquiring a first image acquired by first photographing, a second image acquired by second photographing after the first photographing, and photographing conditions of the first photographing and the second photographing, determination means for determining an afterimage correction area in the second image on the basis of the first image, the second image, and the photographing conditions, and correction means for performing afterimage correction in the afterimage correction area of the second image.

Description

The present invention relates to an information processing apparatus, a control method thereof, an imaging apparatus, and a computer program, and more particularly, to an afterimage correction processing technique when an afterimage is included in a captured image in radiographic imaging.

  Radiographic imaging apparatuses are widely used in many fields such as medical images and industrial nondestructive inspection. Conventionally, an analog radiographic image capturing apparatus using a film has been used for a long time. In recent years, a digital radiographic image capturing apparatus called a flat panel detector (FPD) using a plurality of semiconductor elements for converting radiation into electrical signals arranged in a two-dimensional matrix has been widely used. .

  In a radiographic imaging apparatus using an FPD, after information on radiation that has passed through a subject is charged as a charge in a semiconductor element, a transfer operation is performed to read out the charge information and create digital image information. However, it is difficult to read out all the charges charged in one transfer operation, and a part of the charges may remain even after reading. When the next imaging is performed in this state, a phenomenon occurs in which the remaining charges are superimposed on the next radiation image as an afterimage.

JP 2009-201587 A

  However, in the conventional technique that performs afterimage correction as in Patent Document 1, the following problems may occur. In other words, since it is necessary to newly acquire an image and perform an analysis process immediately before the next image is captured, there is a possibility that the imaging interval until the next imaging becomes possible is long.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an afterimage correction technique that can reduce the influence on the imaging interval when a plurality of radiographic images are captured.

In order to achieve the above object, an information processing apparatus according to the present invention comprises the following arrangement. That is,
An information processing apparatus for processing radiographic images,
The first image acquired by the first shooting, the second image acquired by the second shooting after the first shooting, and the shooting conditions of the first shooting and the second shooting And an acquisition means for acquiring
Determination means for determining an afterimage correction area in the second image based on the first image, the second image, and the photographing condition;
Correction means for performing afterimage correction in the afterimage correction area of the second image.

  According to the present invention, it is possible to provide a technique capable of performing afterimage correction while reducing the influence on the imaging interval when capturing a plurality of radiographic images.

The block diagram which shows the example of the fundamental structure of a radiographic imaging apparatus. The flowchart which shows the procedure of the process which a radiographic imaging apparatus performs. The flowchart which shows the process sequence of an image analysis process. The schematic diagram of the picked-up image in case a radiographic imaging apparatus image | photographs twice. The figure explaining the principle of afterimage threshold value determination. The flowchart which shows the procedure of the process which a radiographic imaging apparatus performs. The flowchart which shows the process sequence of an image analysis process.

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

<< Embodiment 1 >>
(Configuration of radiographic imaging device)
First, the configuration of the radiographic image capturing apparatus according to the first embodiment (Embodiment 1) of the present invention will be described with reference to FIG. FIG. 1 is a block diagram illustrating an example of a basic configuration of a radiographic image capturing apparatus. The radiographic imaging apparatus 100 includes a radiation generation apparatus 101, a bed 103, a detection apparatus 104, a control apparatus 105, a data collection apparatus 106, and an information processing apparatus 107.

  The radiation generation apparatus 101 generates radiation and irradiates the subject 102. A subject 102 such as a human body is laid on the bed 103. The detection device 104 outputs image data corresponding to the radiation that has passed through the subject 102. The control device 105 controls radiation generation conditions such as radiation generation timing and radiation intensity of the radiation generation device 101. The data collection device 106 as an acquisition unit collects various digital data including captured images, shooting conditions output by the detection device 104, the control device 105, and the like. The information processing apparatus 107 performs image processing and overall device control according to user instructions.

  The information processing device 107 includes a determination device 108, an afterimage correction device 109, an image processing device 110, a CPU 112, a memory 113, an operation panel 114, a storage device 115, and a display device 116. Each component of the information processing apparatus 107 is electrically connected via the CPU bus 111. The memory 113 is realized by a ROM (Read Only Memory), a RAM (Writable Memory) or the like. The ROM stores computer programs and various data necessary for processing by the CPU 112, and the RAM operates as a work work memory for the CPU 112. The CPU 112 is a central processing unit, and performs operation control of the entire apparatus in accordance with a user instruction input to the operation panel 114. The operation panel 114 is a component that receives an instruction input from a user, and can be realized by, for example, a keyboard, a pointing device, a touch panel, or the like. The storage device 115 is a device that functions as a large-capacity memory, and can be realized using, for example, a hard disk device or an SSD. The display device 116 displays a command input from the operation panel 114, a response output of the information processing device for the command, and the like. The determination device 108 as a determination unit performs an image analysis process for determining a region (afterimage correction region, afterimage correction necessary region) where an afterimage is to be corrected by analyzing a captured image. An afterimage correction device 109 as a correction unit performs afterimage correction processing for correcting an afterimage in the afterimage correction region of the captured image determined by the determination device 108. The image processing apparatus 110 performs various image processing such as dark correction, noise reduction processing, enhancement processing, and gradation conversion processing on the captured image.

  The information processing apparatus is realized by, for example, a general-purpose personal computer (PC), an embedded system, a tablet terminal, a smartphone, or the like.

  In this embodiment, a case where X-rays are used as radiation will be described as an example. However, the radiation is not limited to X-rays, but other than α-rays, β-rays, γ-rays, etc., which are beams produced by particles (including photons) emitted by radioactive decay, For example, particle beams and cosmic rays are included.

(Operation of radiographic equipment)
Next, the operation of the radiographic image capturing apparatus 100 having the above-described configuration will be described using FIG. FIG. 2 is a flowchart illustrating a procedure of processing performed by the radiographic image capturing apparatus according to the present embodiment. In this example, two images are continuously photographed, and afterimage correction is performed on the second image. The following steps are executed based on the control of the CPU 112.

  In step S <b> 201, the radiographic image capturing apparatus 100 captures a dark image by capturing an image without irradiating X-rays before capturing the subject 102 according to the user's instruction. The dark image is used for performing dark correction for removing dark current noise and fixed pattern noise of the detection device 104. Here, a plurality of dark images are taken and averaged to be held in a state in which random noise is reduced. When the charge accumulation time in photographing is not constant, a plurality of dark images having a plurality of accumulation times may be acquired and switched according to the accumulation time at the time of photographing.

Next, the photographing operation of the first subject is started in accordance with a user instruction. In S202, first, the data collection device 106 acquires information indicating the first imaging condition. Examples of the first shooting condition include the following.
The distance between the radiation generation apparatus 101 and the detection apparatus 104 (SID: (Source Image Distance)).
-X-ray irradiation conditions (tube voltage, tube current, irradiation time, etc.).
-Types of attenuators such as grids, presence and absence, and transmittance.
The sensitivity S of the detection device 104;
The operating temperature T of the detector 104;

  In S203, X-rays are irradiated from the radiation generation apparatus 101 to the detection apparatus 104, and first image capturing is performed. Hereinafter, the image acquired by the first image shooting is referred to as a first image.

  In S204, various image processing such as dark correction, noise reduction processing, enhancement processing, and gradation conversion processing by the image processing apparatus 110 is performed on the first image. The dark correction can be performed by subtracting the dark image acquired in S201, for example. The image subjected to image processing is subjected to operations such as storage in the storage device 115 and display on the display device 116 in accordance with a user instruction.

  Next, the photographing operation for the second subject is started according to the user's instruction. In step S205, the data collection device 106 acquires information indicating the second shooting condition. The second shooting condition includes a (narrowly defined) shooting condition related to the image shooting performed in S206 and an image processing condition related to the image processing performed in S210. The imaging conditions include, for example, the time interval t from the first imaging to the second imaging, the charge accumulation time C in the imaging of the detection device 104 in the second imaging, and the like. The image processing conditions include a gradation curve used for gradation conversion processing in the second image processing, an image processing parameter related to enhancement processing, and the like. Note that the above examples of the first shooting conditions are all related to the image shooting performed in S203, and thus are in a narrow sense.

  In S206, the detection device 104 is irradiated with X-rays, and second image capturing is performed. Hereinafter, the image acquired by the second image shooting is referred to as a second image.

  In S207, image analysis processing by the determination device 108 is performed. The image analysis process is a process of analyzing the first image acquired in S203 and the second image acquired in S206, determining an area that requires afterimage correction in the second image, and labeling the area. It is. Details of the image analysis processing will be described later.

  In S208, in response to the result of S207, the process branches depending on whether or not it is necessary to perform afterimage correction on the second image. That is, if it is determined that there is an area that requires afterimage correction processing in the second image (YES in S208), the process proceeds to S209. If it is determined that no afterimage correction processing is necessary (NO in S208), the process proceeds to S210. move on.

  In S209, afterimage correction processing is performed to correct the region of the second image determined to require afterimage correction in the image analysis processing in S207, and remove the afterimage. Details of the afterimage correction processing will be described later.

  In S210, various image processing such as dark correction, noise reduction processing, enhancement processing, and gradation conversion processing by the image processing apparatus 110 is performed on the second image. Note that the dark correction is performed, for example, by subtracting the dark image acquired in S201. The image subjected to image processing is subjected to operations such as storage in the storage device 115 and display on the display device 116 in accordance with a user instruction. Then, the process ends.

(Image analysis processing)
Next, details of the image analysis processing in S207 of FIG. 2 performed by the determination apparatus 108 will be described with reference to FIGS. FIG. 3 is a flowchart of the image analysis process. FIG. 4 is a schematic diagram of a photographed image when photographing is performed twice according to the flow of FIG. FIG. 4A shows an example of a captured image of the first image, and FIG. 4B shows an example of a captured image of the second image. FIG. 5 is a diagram for explaining the processing performed in S302.

  In S301, the second image is divided into three regions based on the pixel values of the first image. Hereinafter, the pixel value at the coordinates (x, y) of the first image will be described as I (x, y) using the example of the first image shown in FIG. The first area 401 is a subject area where I (x, y) <Th1. The X-rays pass through the subject 102 and the intensity thereof is attenuated to reach the detection device 104. For this reason, the amount of electric charge accumulated during photographing is small, and the amount of residual electric charge remaining as an afterimage after readout is also small. The second region 402 is a blank region where I (x, y) ≧ Th1. Since X-rays do not pass through the subject 102 and directly reach the detection device 104, the amount of charge accumulated during imaging increases, and afterimages tend to remain after reading. The third region 403 is a boundary region where | I (x, y) −I (x + 1, y) | ≧ Th2 or | I (x, y) −I (x, y + 1) | ≧ Th2. The difference in accumulated charge amount (pixel value) between adjacent pixels is large, and the afterimage can appear as a steep step. Here, the threshold values Th <b> 1 and Th <b> 2 are values determined in advance according to the characteristics of the detection device 104.

In S <b> 302, the amount of afterimage that can be included in the second image based on the image processing conditions related to the image processing performed on the second image acquired by the data collection device 106 and the pixel value of the second image. An acceptable threshold is calculated. The afterimage that has the most adverse effect in diagnosis is a steep stepped shape that occurs at the boundary between a region where a lot of afterimages are generated and a region where no afterimages occur so much. It is greatly influenced by the following three factors.
-The first factor is the relationship between the amount of step and the surrounding pixel values. As the surrounding pixel value is smaller, the ratio of the step to the signal increases and becomes more conspicuous. From this relationship, it is possible to create an LUT having such a characteristic that the allowable afterimage threshold value decreases as the pixel value of the second image decreases, and can be used as the first threshold value determining means.
The second element is the relationship between the region where the step has occurred and the gradation curve used for the image processing executed in S210. For example, as shown in FIG. 5A, when a general sigmoid curve is used as a gradation curve, the regions 501 and 502 having the same step amount before gradation conversion are steeper after the gradation change. 502 where gradation conversion is performed is displayed with emphasis (503, 504). In other words, the steep gradation change due to the gradation curve is more likely to cause a residual image, and the threshold value needs to be reduced. From this point, in consideration of the effect of gradation conversion for each gradation curve to be applied, the relationship between the pixel value of the second image and the threshold value of the afterimage is used as the second threshold value determining means by having as a LUT. it can.
-Third, it is related to the enhancement process. When frequency edge enhancement processing typified by unsharp mask processing is performed, stepped artifacts are displayed with higher emphasis. As shown in FIG. 5B, as the enhancement process becomes stronger, the allowable afterimage threshold tends to be smaller. From this, it is possible to use, as the third threshold value determining means, a product obtained by multiplying the LUT determined by the first and second threshold value determining means by a coefficient according to the strength of the enhancement process and the presence / absence thereof.

  In accordance with the above consideration factors, the afterimage threshold value for each pixel is determined according to the pixel value of the second image, the type of gradation curve selected according to the subject, and the strength of the enhancement process. As a threshold setting method, for example, visual evaluation is performed in advance based on various criteria, a threshold LUT corresponding to the criteria is created, and the threshold can be determined based on the LUT. At that time, the first to third threshold value determining means may be used alone or in combination. In the example of FIG. 4B, an area corresponding to 402 having a boundary 403 where an afterimage may occur as a step becomes more noticeable in the subject area 404 than the unexposed area 405, and the afterimage threshold is lower. Become.

In S303, the afterimage amount of the second image is estimated based on the pixel value of the first image, the shooting condition of the first image, and the shooting condition of the second image. If the afterimage amount remaining in the second image is L (x, y), the pixel value I (x, y) of the first image, the shooting interval t, the operating temperature T, and the second shooting accumulation time From C, it can be estimated using Equation 1 shown below. Here, the coefficients α and β are coefficients determined by the characteristics of the detection device 104. In the first image, as indicated by 402 in FIG. 4A, when the X-ray directly reaches the detection device 104, the digital output value of the detection device 104 is saturated, and I (x , Y) may be estimated lower than actual. For this reason, when I (x, y) is a certain value Th or more,
The SID acquired as the first shooting condition.
-X-ray irradiation conditions (tube voltage, tube current, irradiation time).
・ Transmittance according to the type of grid.
The transmittance of the attenuator between the radiation generator 101 and the subject.
From this, the arrival dose E reaching the detection device 104 is calculated. Then, I (x, y) is estimated from the sensitivity S of the detection device 104 by I (x, y) = E / S. Here, Th is a constant determined from the saturation characteristic of the detection device 104.
[Formula 1]
L (x, y) = αC × I (x, y) exp (−βTt)
if I (x, y) ≧ Th then I (x, y) = E / S.

  In step S304, the threshold value of each pixel calculated in step S302 is compared with the afterimage amount of the second image estimated in step S303, and an area that requires afterimage correction is labeled. Specifically, an area where the afterimage amount exceeds the allowable threshold is determined as an area that requires afterimage correction. Here, when the processing time when performing the processing of S302 to S304 on the entire image becomes a problem, the processing area may be limited to increase the speed. Referring to FIG. 4 as an example, the step-like afterimage, which can be the most problematic, occurs only at the same coordinates as the third region 403 in the first image. For this reason, the processes in S302 to S304 may be performed on the area around the third area 403, and the process may be terminated if the area that requires afterimage correction is not labeled.

(Afterimage correction processing)
In S209 of FIG. 2, the afterimage correction apparatus 109 performs a process of subtracting the estimated afterimage amount L from the second image in an area where afterimage labeling by the determination apparatus 108 is necessary. If the pixel value at the coordinates (x, y) of the second image is J (x, y), correction processing is performed as shown in Equation 2 to create an afterimage corrected image K (x, y).
[Formula 2]
K (x, y) = J (x, y) -L (x, y).

  As described above, according to the present embodiment, it is not necessary to acquire afterimage data again when acquiring the second image, which may affect the imaging interval until the next imaging is possible. Absent. That is, in the present embodiment, the first image acquired by the first shooting, the second image acquired by the second shooting after the first shooting, and the first and second shooting The imaging conditions are acquired, and the afterimage correction area of the second image is determined based on the first and second images and the imaging conditions. Then, afterimage correction is performed in the afterimage correction area of the second image. In other words, when the first image is acquired, the shooting conditions of the first image and the first image are held, and when the second image is acquired, these information and the second image are acquired. Afterimage correction is performed on the second image based on the imaging conditions and the second image itself. As described above, in this embodiment, since it is not necessary to acquire and analyze an image immediately before the second shooting, it is possible to start shooting in a short time in accordance with the second shooting instruction.

  Further, by analyzing the second image and determining the necessity for afterimage correction, it is possible to select and process only a region having a high afterimage risk more accurately. That is, in the present embodiment, an image analysis based on the pixel values of the first and second images, the first and second imaging conditions, and the like in the second image that requires afterimage correction by the first imaging. And afterimage correction is performed as necessary. For this reason, it is possible to appropriately reduce the occurrence of afterimage remaining due to failure of afterimage correction processing, artifacts due to unnecessary afterimage correction processing, and noise increase according to the properties of the image.

<< Embodiment 2 >>
Next, the configuration of the radiographic image capturing apparatus according to the second embodiment of the present invention will be described. The basic apparatus configuration of this embodiment is shown in FIG. Many of the processing flows according to the present embodiment are also common to the first embodiment. Therefore, detailed description of overlapping configurations and processes will be omitted, and differences from the first embodiment will be mainly described.

  As a dark correction method, the radiographic image capturing apparatus according to the second embodiment captures a dark image under the same conditions immediately after reading a captured image every time a subject is captured, as disclosed in JP-A-2003-244557. The subtraction process is performed. Here, there is a difference that the image used in the analysis performed by the determination apparatus 108 is the first image in the first embodiment, but is the first dark image in the second embodiment.

(Operation of radiographic equipment)
The operation of the radiation image capturing apparatus 100 according to the second embodiment will be described with reference to FIG. FIG. 6 is a flowchart of processing performed by the radiographic image capturing apparatus according to the second embodiment. In this example, two images are continuously photographed, and afterimage correction is performed on the second image. The processes in S601, S602, S605 to S607, and S610 to S613 in FIG. 6 are the same as the processes in S202 to S210 in FIG. The following steps are executed based on the control of the CPU 112.

  In step S601, a shooting operation for the first subject is started in accordance with a user instruction. Here, the operating temperature of the detection device 104 is acquired as the first imaging condition. In step S602, the subject 102 and the detection device 104 are irradiated with X-rays, and a first image is taken.

  In step S603, the first dark image is captured. The dark image shooting is equivalent to the first image shooting in the state where the subject 102 does not exist immediately after the first image shooting is completed and the read operation is performed using the first shooting conditions acquired in S601. Is done in the accumulation time. In S604, dark correction of the first image is performed. The dark correction process subtracts the first dark image from the first image.

  In step S <b> 605, various image processing such as noise reduction processing, enhancement processing, and gradation conversion processing by the image processing apparatus 110 is performed on the first image. The processed image is subjected to processing such as storage in the storage device 115 and display on the display device 116 in accordance with a user instruction.

  Next, the photographing operation for the second subject is started in accordance with the user's instruction. In step S606, the data collection device 106 acquires information indicating the second imaging condition. The second shooting condition includes a (narrowly defined) shooting condition related to the image shooting performed in S607 and an image processing condition related to the image processing performed in S613. The shooting conditions include, for example, an accumulation time in shooting, a time interval from the first shooting to the second shooting, and the like. The image processing conditions include, for example, a gradation curve performed in the second image processing, an image processing parameter related to enhancement processing, and the like.

  In step S <b> 607, the subject 102 and the detection device 104 are irradiated with X-rays, and second image shooting is performed. In step S608, the second dark image is captured. The dark image is captured immediately after the second image is captured and the readout operation is performed, with the same accumulation time as the second image capturing in the absence of the subject 102. In S609, dark correction of the second image is performed. Similar to S604, in the dark correction process, the second dark image is subtracted from the second image.

  In S610, image analysis processing by the determination device 108 is performed. The image analysis process analyzes the first dark image acquired in S603 and the second image that has undergone dark correction in S609, determines an area in the second image that requires afterimage correction, This is a process of labeling an area. Details of the image analysis processing will be described later.

  In S611, in response to the result of S610, the process branches depending on whether or not afterimage correction is necessary for the second image. That is, if it is determined that the afterimage correction process is necessary for the second image (YES in S611), the process proceeds to S612. If it is determined that the afterimage correction process is not necessary (NO in S611), the process proceeds to S613.

  In S612, afterimage correction processing is performed on the second image. Details of the afterimage correction processing are the same as those in the first embodiment.

In step S613, the image processing apparatus 110 performs various image processing such as noise reduction processing, enhancement processing, and gradation conversion processing on the second image. The image subjected to image processing is subjected to operations such as storage in the storage device 115 and display on the display device 116 in accordance with a user instruction. Then, the process ends.
(Image analysis processing)
Next, details of the image analysis processing in S610 performed by the determination apparatus 108 will be described with reference to FIG. FIG. 7 is a flowchart of image analysis processing according to the second embodiment. The basic processing contents are the same as S301 to S304 of the first embodiment, but the target of the image to be analyzed is the first image in S301 of the first embodiment, whereas the first image is the first in the second embodiment. There is a difference in dark images. Since the first dark image is an image taken immediately after reading out the first image, there is very little possibility that the output is saturated even when a strong dose is applied, and the amount of charge remaining depending on the time of photographing is directly grasped. can do.

In S701, the image is divided into three regions based on the pixel values of the first dark image. Hereinafter, the pixel value at the coordinates (x, y) of the first dark image is set to D (x, y), and the image is divided into the following three regions as in S301.
A region where D (x, y) <Th3.
A region where D (x, y) ≧ Th3.
A region where | D (x, y) −D (x + 1, y) | ≧ Th4 or | D (x, y) −D (x, y + 1) | ≧ Th4.
Here, the threshold values Th <b> 3 and Th <b> 4 are values determined in advance according to the characteristics of the detection device 104.

  In S <b> 702, as in S <b> 302, the allowable threshold for the afterimage amount that can be included in the second image based on the conditions acquired by the data collection device 106 and the pixel value of the second image on which dark correction has been performed in S <b> 609. Is calculated.

In S703, the afterimage amount of the second image is estimated. When the amount of afterimage remaining in the second image is L (x, y), L (x, y) is the pixel value D (x, y) of the first dark image, the shooting interval t, and the operating temperature T. From the accumulation time C of the second imaging, it can be estimated using the following formula 3. Here, the coefficients γ and δ are coefficients that vary depending on the characteristics of the detection device 104.
[Formula 3]
L (x, y) = γC × D (x, y) exp (−δTt).

  In step S704, the threshold value of each pixel calculated in step S702 is compared with the afterimage amount of the second image estimated in step S703, and an area that requires afterimage correction is labeled.

  As described above, in the present embodiment, a region requiring afterimage correction is determined using the first dark image and the second image after dark correction, and afterimage correction is performed for the region. For this reason, according to the present embodiment, even in a photographing apparatus that needs to perform dark image photographing and perform offset correction every time an image is photographed, such as a moving image photographing apparatus, the photographing interval is not affected. Thus, it is possible to perform afterimage correction appropriately.

  In the present embodiment, in the image analysis processing in S610, the afterimage correction necessary area is determined using the first dark image acquired in S603 and the second dark corrected image acquired in S609. It is not limited to this. For example, instead of the first dark image, the dark corrected first image acquired in S604 may be used.

<< Other Embodiments >>
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

Claims (14)

An information processing apparatus for processing radiographic images,
The first image acquired by the first shooting, the second image acquired by the second shooting after the first shooting, and the shooting conditions of the first shooting and the second shooting And an acquisition means for acquiring
Determination means for determining an afterimage correction area in the second image based on the first image, the second image, and the photographing condition;
An information processing apparatus comprising: correction means for performing afterimage correction in the afterimage correction area of the second image. The acquisition unit further acquires an image processing condition related to image processing performed on the second image,
The determination means includes
Calculating means for calculating an allowable threshold for an afterimage amount included in each pixel of the second image based on at least one of the pixel value of the second image and the image processing condition;
Estimating means for estimating an afterimage amount included in each pixel of the second image based on a pixel value of the first image and the photographing condition;
And a determination unit configured to determine the afterimage correction area in the second image by comparing the allowable threshold calculated by the calculation unit with the afterimage amount estimated by the estimation unit. Item 4. The information processing apparatus according to Item 1.   The information processing apparatus according to claim 2, wherein the calculation unit calculates a smaller allowable threshold for a pixel having a smaller pixel value in the second image.   The calculation means calculates a smaller allowable threshold for a pixel indicated by the image processing condition and having a larger gradation change due to image processing performed on the second image. Item 4. The information processing apparatus according to Item 2 or 3. The imaging conditions include an imaging interval between the first imaging and a second imaging, an operating temperature of a detecting unit that detects radiation from a generating unit that generates radiation, and the second imaging. Charge accumulation time in the detection means, and
5. The afterimage amount is estimated based on the photographing interval, the operating temperature, the accumulation time, and a pixel value of the first image. The information processing apparatus according to any one of claims. The estimation means estimates the afterimage amount L (x, y) at the coordinates (x, y), the pixel value I (x, y) of the first image, the imaging interval t, and the operating temperature. Using T, the accumulation time C, and the coefficients α and β determined by the type of the detection means,
L (x, y) = αC × I (x, y) exp (−βTt)
The information processing apparatus according to claim 5, wherein The imaging conditions include the distance between the generating means and the detecting means, the irradiation condition of the radiation by the generating means, the sensitivity of the detecting means, and the transmittance of the attenuating body between the generating means and the subject. And at least one of
When the pixel value of the first image exceeds a certain value, the estimation unit calculates an arrival dose to the detection unit based on at least one of the distance, the irradiation condition, and the transmittance. The afterimage amount L (x, y) is estimated using the pixel value I (x, y) as a value estimated from the arrival dose and the sensitivity instead of the pixel value of the first image. The information processing apparatus according to claim 6.   The information processing apparatus according to any one of claims 2 to 7, wherein the determination unit determines an area in which the afterimage amount exceeds the allowable threshold as the afterimage correction area.   The said correction | amendment means subtracts the said afterimage amount estimated by the said estimation means from the pixel value of a said 2nd image, The said afterimage correction is performed, The any one of Claim 2 to 8 characterized by the above-mentioned. Information processing device. Before the first imaging, further comprising a control means for controlling the generating means and the detecting means so as to obtain a dark image by irradiating with radiation in the absence of a subject,
The information processing apparatus according to claim 5, wherein dark correction is performed on the first image and the second image by subtracting the dark image, respectively. The control means controls the generation means and the detection means so as to acquire a dark image by irradiating with radiation in a state where no subject exists after each photographing,
The estimation means estimates the afterimage amount L (x, y) at coordinates (x, y), a pixel value D (x, y) of a dark image acquired immediately after the first image, and the Using the imaging interval t, the operating temperature T, the accumulation time C, and the coefficients γ and δ determined by the type of the detection means,
L (x, y) = γC × D (x, y) exp (−δTt)
The information processing apparatus according to claim 10, wherein: A radiographic imaging device that captures radiographic images,
The first image acquired by the first shooting, the second image acquired by the second shooting after the first shooting, and the shooting conditions of the first shooting and the second shooting And an acquisition means for acquiring
Determination means for determining an afterimage correction area in the second image based on the first image, the second image, and the photographing condition;
A radiographic imaging apparatus comprising: correction means for performing afterimage correction in the afterimage correction area of the second image. A control method for an information processing apparatus that processes a radiation image,
The acquisition means includes a first image acquired by the first shooting, a second image acquired by the second shooting after the first shooting, the first shooting, and the second image. An acquisition process for acquiring the shooting conditions of the shooting;
A determination step of determining a residual image correction area in the second image based on the first image, the second image, and the imaging condition;
A control method for an information processing apparatus, comprising: a correction unit that performs afterimage correction in the afterimage correction area of the second image.   The computer program for functioning a computer as each means with which the information processing apparatus of any one of Claim 1 to 11 is provided.

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