A flat panel detector and its residual image correction method and detection system

Abstract

The present invention discloses a flat panel detector and a method and a detection system for correcting afterimages thereof, which are used to solve the technical problem in the prior art that the correction of images collected by an X-ray radio frequency detector is not fast and accurate enough. The method comprises: obtaining a time difference between a first image currently collected and a second image collected last time; determining, according to a relationship between the time difference and a light attenuation duration corresponding to the scintillator, an afterimage caused by the scintillator of the flat panel detector when collecting the second image, the grayscale of the afterimage at the ambient temperature when the flat panel detector collects the first image, and using the grayscale of the afterimage as a grayscale correction amount corresponding to the first image; and performing afterimage correction on the first image using the grayscale correction amount to obtain a corrected first image.

Description

Technical Field

[0001] The present invention relates to the field of imaging, and in particular to a flat panel detector and a method and a detection system thereof for correcting residual images. Background Art

[0002] Digital X-ray detectors are divided into direct X-ray detection and indirect detection. In comparison, indirect detection detectors have higher durability and DQE, lower cost, and are more widely used.

[0003] The indirect detection X-ray detector includes a thin film transistor (TFT) switch device array, and a photodiode device corresponding to each TFT device. The above two devices together constitute a pixel, and a scintillator covering the entire X-ray detector panel. The working principle of the indirect detection X-ray detector is: when X-rays irradiate the panel, the X-rays are converted into visible light through the scintillator, and the visible light continues to pass downward to the photodiode in the reverse bias state, converting the optical signal into an electrical signal and storing it in the storage capacitor of the pixel, and then opening the TFT switch devices row by row according to the readout timing, reading the data by reading the chip degree, and forming an image.

[0004] Due to the non-uniformity of the X-ray detector production process, there are slight differences between TFT and photodiode devices, as well as the non-uniformity of X-ray irradiation. Even the blank images often have the problem of uneven pixel grayscale. Image correction is often required to address this phenomenon. Existing image correction methods include dark field correction and gain correction, but the above image correction methods cannot handle the residual image caused by the acquisition of the previous frame of the image. The causes of the afterimage include two parts, namely the afterglow of the scintillator and the capture and release of electrons by the defects of the photodiode. For the release of the residual electrons of the photodiode, it can be achieved by resetting the photodiode or providing an electric field reversal for the photodiode when the X-ray detector is in an idle state. The afterglow of the scintillator is difficult to release quickly through human intervention. Since the release time of the afterglow of the scintillator is long, it is inevitable that the user (such as a doctor) needs to wait, or during continuous image acquisition, the image contains the residual image of the previous frame acquisition, which confuses the user's judgment.

[0005] In view of this, how to quickly and accurately correct the images collected by X-ray radio frequency detectors has become a technical problem that needs to be solved urgently. Summary of the invention

[0006] The present invention provides a flat panel detector and a method and a detection system for correcting an afterimage thereof, which are used to solve the technical problem in the prior art that the correction of images collected by an X-ray radio frequency detector is not fast and accurate enough.

[0007] In the first aspect, in order to solve the above technical problems, the technical solution of a method for correcting afterimages of a flat panel detector provided by an embodiment of the present invention is as follows:

[0008] Obtaining the time difference between the currently acquired first image and the last acquired second image;

[0009] Determine, according to the relationship between the time difference and the light attenuation duration corresponding to the scintillator, an afterimage caused by the scintillator of the flat-panel detector when acquiring the second image, the grayscale of the afterimage at the ambient temperature when the flat-panel detector acquires the first image, and use the grayscale of the afterimage as the grayscale correction amount corresponding to the first image;

[0010] Perform afterimage correction on the first image using the grayscale correction amount to obtain a corrected first image.

[0011] In a possible implementation, obtaining the time difference between capturing the current first image and the last second image includes:

[0012] Acquire a first time of acquiring the first image;

[0013] Acquire a second time for acquiring the second image;

[0014] A difference operation is performed on the first time and the second time to obtain the time difference.

[0015] In a possible implementation manner, determining, according to a magnitude relationship between the time difference and a light attenuation duration corresponding to the scintillator, an afterimage caused by the scintillator of the flat panel detector when acquiring the second image, and a grayscale of the afterimage at an ambient temperature when the flat panel detector acquires the first image, includes:

[0016] If the time difference is greater than or equal to the light attenuation duration corresponding to the scintillator, the grayscale of the afterimage is 0;

[0017] If the time difference is less than the light attenuation duration corresponding to the scintillator, the grayscale of the afterimage is determined according to the second image, the light attenuation coefficient corresponding to the second image, the ambient temperature, and the time difference.

[0018] In a possible implementation manner, determining the grayscale of the afterimage according to the second image, the light attenuation coefficient corresponding to the second image, the ambient temperature, and the time difference includes:

[0019] The ambient temperature and the time difference are calculated using a preset relationship to determine the light attenuation coefficient; wherein the preset relationship is determined based on the first dark state image and the second dark state image corresponding to different interval lengths under different temperature conditions of the flat panel detector, the first dark state image is a dark state image collected after exposing the bright state image, and the second dark state image is a dark state image after the interval length is fitted based on the bright state image;

[0020] A product operation is performed on the second image, the light attenuation coefficient, the current temperature, and the time difference to obtain a grayscale of the residual image.

[0021] In a possible implementation manner, the method for obtaining the preset relationship includes:

[0022] Under different test environment temperatures, collecting the bright state image, and after exposing the bright state image, collecting the first dark state image;

[0023] Fitting the grayscale value of the second dark-state image at the test environment temperature according to the bright-state image and at the interval time after the bright-state image is collected;

[0024] The preset relationship is determined according to the grayscale value of the first dark state image, the grayscale value of the second dark state image, and the interval time.

[0025] In a possible implementation manner, the preset relationship is:

[0026] a t =[Graylevel(1st) t –Graylevel(n) t ] / [Time·Graylevel(1st) t ];

[0027] Wherein, t is the test environment temperature, a t is the light attenuation coefficient at the test ambient temperature, Graylevel(1st) t Graylevel(n) is the grayscale value of the first dark state image at the test ambient temperature. t is the grayscale value of the second dark state image under the test environment temperature, and Time is the set time length.

[0028] In a possible implementation manner, correcting the first image using the grayscale correction amount to obtain a corrected first image includes:

[0029] A matrix difference operation is performed on the first image and the grayscale correction amount to obtain the corrected first image.

[0030] In a second aspect, an embodiment of the present invention provides a flat panel detector, comprising:

[0031] Flat panel detector panel;

[0032] A temperature sensor, disposed in the flat panel detector panel, for collecting the ambient temperature of the environment where the flat panel detector panel is located;

[0033] The programmable logic array FPGA is used to store a preset relationship for determining the light attenuation coefficient, collect a first image from the flat panel detector panel, and obtain the current ambient temperature from the temperature sensor to execute the method described in the first aspect.

[0034] In a possible implementation manner, the flat panel detector panel includes:

[0035] A plurality of light emitting diodes arranged in a neat pattern, and thin film transistors corresponding to the plurality of light emitting diodes one by one;

[0036] The thin film transistor is reset during idle time, and at the same time, the electric field of the light emitting diode is reversed.

[0037] In a third aspect, an embodiment of the present invention further provides a detection system, including:

[0038] The flat panel detector according to the second aspect;

[0039] The host computer is used to acquire images from the flat panel detector and display the images. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A flowchart of a flat panel detector afterimage correction method provided by an embodiment of the present invention;

[0041] Figure 2 A schematic diagram of the structure of a flat panel detector provided by an embodiment of the present invention;

[0042] Figure 3 A schematic diagram of the structure of a detection system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The embodiment of the present invention provides a flat panel detector and a method and a detection system for correcting afterimages thereof, so as to solve the technical problem in the prior art that the correction of images collected by X-ray radio frequency detectors is not fast and accurate enough.

[0044] In order to better understand the above technical scheme, the technical scheme of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical scheme of the present invention, rather than limitations on the technical scheme of the present invention. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0045] The luminescence mechanism of the scintillator of the flat-panel detector is as follows: high-energy X-rays irradiate the flat-panel detector, causing the electrons in the valence band of the scintillator material in the flat-panel detector to cross the forbidden band to reach the conduction band, and gradually release energy in the subsequent de-excitation process. The energy is released in the form of photons, and its light decay time is long, so afterglow will continue to be generated for a certain period of time. The long afterglow release time of the scintillator inevitably causes users (such as doctors) to wait, or when continuous image acquisition, the image contains the residual image of the previous frame acquisition, confusing the user's judgment.

[0046] In order to reduce the influence of residual image on the collected image, the present invention provides the following solutions:

[0047] Please refer to Figure 1 An embodiment of the present invention provides a method for correcting afterimages of a flat panel detector, and the processing process of the method is as follows.

[0048] Step 101: Obtaining a time difference between a currently captured first image and a last captured second image;

[0049] Usually, when a flat panel detector is used, it needs to be turned on and preheated, and then a variety of initial dark state images and initial bright state images without obstructions are collected to make dark field correction templates, bright field correction templates and gain correction templates. The above templates need to be substituted into the collected images for basic image correction during subsequent normal image collection. Therefore, the first image and the second image in the embodiment of the present invention may refer to images after the above basic image correction is implemented.

[0050] The above-mentioned acquisition of the time difference between the current first image and the last second image can be achieved by the following method:

[0051] Acquire a first time for acquiring a first image; acquire a second time for acquiring a second image;

[0052] A difference operation is performed on the first time and the second time to obtain a time difference.

[0053] For example, the first time to acquire the first image of the flat panel detector is t 1 , the second time when the second image was acquired last time is t 2 , then the time difference between collecting the first image and the second image is t 1 -t 2 .

[0054] Of course, in addition to using the above method to calculate the time difference between capturing the first image and the second image, the time difference between capturing the first image and the second image can also be determined in other ways, such as starting a timer after capturing the second image, stopping the timer when capturing the first image, and reading the value in the timer as the time difference between capturing the first image and the second image.

[0055] After obtaining the time difference between the currently acquired first image and the last acquired second image, step 102 and step 103 may be performed.

[0056] Step 102: determining the grayscale of the residual image caused by the scintillator of the flat panel detector when acquiring the second image at the ambient temperature when the flat panel detector acquires the first image according to the relationship between the time difference and the light attenuation time corresponding to the scintillator, and using the grayscale of the residual image as the grayscale correction amount corresponding to the first image;

[0057] Step 103: Correct the first image using the grayscale correction amount to obtain a corrected first image.

[0058] In the embodiment provided by the present invention, by obtaining the time difference between the currently acquired first image and the last acquired second image; and according to the relationship between the time difference and the light attenuation duration corresponding to the scintillator, determining the afterimage caused by the scintillator of the flat-panel detector when acquiring the second image, and the grayscale of the afterimage at the ambient temperature when acquiring the first image, and using it as the grayscale correction amount corresponding to the first image; and then using the grayscale correction amount to perform afterimage correction on the first image to obtain a corrected first image, thereby reducing the afterimage contained in the corrected first image. Since the afterimage in the corrected first image is reduced, the user does not need to wait for the afterglow of the scintillator to be completely released before using it, and can thus continuously acquire images, and quickly and accurately acquire the image acquired by the corrected flat-panel detector, thereby improving the user's work efficiency.

[0059] In step 102, the grayscale of the residual image caused by the scintillator of the flat panel detector when acquiring the second image at the ambient temperature when the flat panel detector acquires the first image is determined according to the relationship between the time difference and the light attenuation duration corresponding to the scintillator. This can be achieved by:

[0060] If the time difference is greater than or equal to the light attenuation duration corresponding to the scintillator, the grayscale of the afterimage is 0;

[0061] If the time difference is less than the light attenuation time corresponding to the scintillator, the grayscale of the residual image is determined according to the second image, the light attenuation coefficient corresponding to the second image, the ambient temperature, and the time difference. The above light attenuation coefficient is related to the material properties of the scintillator and can usually be affected by temperature. In practical applications, the flat panel detector can provide corresponding settings to set whether the above light attenuation coefficient is allowed to be used.

[0062] For example, if the time difference between the currently acquired first image and the last acquired second image is greater than or equal to the light attenuation duration corresponding to the scintillator, it can be determined that the grayscale of the afterimage caused by the scintillator of the flat-panel detector when acquiring the second image is 0 after the above time difference (that is, the grayscale correction amount corresponding to the first image is 0). This indicates that the interval between acquiring the first image and acquiring the second image is relatively long and has exceeded the light attenuation duration corresponding to the scintillator. In this case, there is no need to perform afterimage correction on the first image, that is, the first image can be used as the corrected first image.

[0063] For another example, the time difference between the currently acquired first image and the last acquired second image is less than the light attenuation time corresponding to the scintillator, which means that the interval between acquiring the first image and acquiring the second image is short. When acquiring the second image, the afterimage caused by the scintillator of the flat-panel detector will affect the first image. At this time, it is necessary to determine the grayscale correction amount based on the second image, the light attenuation coefficient corresponding to the second image, the corresponding ambient temperature when acquiring the first image, and the time difference, and use the determined grayscale correction amount to perform afterimage correction on the first image to obtain the corrected first image.

[0064] In the embodiment provided by the present invention, when the time difference between the first image collected and the second image collected last is greater than or equal to the light attenuation duration corresponding to the scintillator, the grayscale of the afterimage is set to 0; and when the time difference between the first image collected and the second image collected last is less than the light attenuation duration corresponding to the scintillator, the grayscale of the afterimage at the ambient temperature when the flat-panel detector collects the first image is determined based on the second image, the light attenuation coefficient corresponding to the second image, the ambient temperature, and the time difference, and then the grayscale of the afterimage is used to perform afterimage correction on the first image, so as to quickly remove the influence of the afterimage on the first image.

[0065] In a possible implementation, the grayscale of the residual image is determined according to the second image, the light attenuation coefficient corresponding to the second image, the ambient temperature, and the time difference, which can be achieved in the following manner:

[0066] The ambient temperature and the time difference are calculated using a preset relationship to determine the light attenuation coefficient; wherein the preset relationship is determined based on the first dark state image and the second dark state image corresponding to different interval lengths under different temperature conditions of the flat-panel detector, the first dark state image is a dark state image captured after exposing the bright state image, and the second dark state image is a dark state image after the interval length is fitted according to the bright state image; a product operation is performed on the second image, the light attenuation coefficient, the current temperature, and the time difference to obtain a grayscale correction amount.

[0067] The above-mentioned preset relationship can be obtained by the following methods:

[0068] Under different test environment temperatures, a bright state image is collected, and after exposing the bright state image, a first dark state image is collected; the grayscale value of a second dark state image separated by an interval time from the collection of the bright state image under the test environment temperature is fitted based on the bright state image; a preset relationship is determined based on the grayscale value of the first dark state image, the grayscale value of the second dark state image, and the interval time.

[0069] The default relationship is:

[0070] a t =[Graylevel(1st) t –Graylevel(n) t ] / [Time·Graylevel(1st) t ];

[0071] Where, t is the test environment temperature, a t is the light attenuation coefficient at the test ambient temperature, Graylevel(1st) t Graylevel(n) is the gray value of the first dark state image at the test ambient temperature. t is the grayscale value of the second dark state image under the test environment temperature, and Time is the set duration.

[0072] For example, before leaving the factory, bright-state images at corresponding ambient temperatures can be collected at different ambient temperatures (such as at 10 ambient temperatures respectively), and the corresponding first dark-state image can be collected immediately after exposing the bright-state image. The grayscale value of the second dark-state image corresponding to a period of time (such as interval duration) after the interval exposure of the bright-state image is fitted based on the bright-state image, and then the preset relationship is determined based on the relationship between the grayscale value of the second dark-state image and the grayscale value of the first dark-state image.

[0073] The relationship between the grayscale value of the second dark state image and the grayscale value of the first dark state image is:

[0074] Graylevel(n) t =Graylevel(1st) t –a t Graylevel (1st) t Time;

[0075] Where, t is the test environment temperature, a t is the light attenuation coefficient at the test ambient temperature, Graylevel(1st) t Graylevel(n) is the gray value of the first dark state image at the test ambient temperature. t is the grayscale value of the second dark state image under the test environment temperature, and Time is the set duration.

[0076] According to the relationship between the grayscale value of the second dark state image and the grayscale value of the first dark state image, the preset relationship can be determined as:

[0077] a t =[Graylevel(1st) t –Graylevel(n) t ] / [Time·Graylevel(1st) t ].

[0078] After obtaining the above relationship, the above relationship can be stored in the flat panel detector. After leaving the factory, when the flat panel detector is actually used, after the flat panel detector acquires the first image, if the time difference between acquiring the first image and acquiring the second image is less than the light attenuation time corresponding to the scintillator, the above preset relationship can be read to determine the light attenuation coefficient corresponding to the ambient temperature at which the first image is acquired, and then the determined light attenuation coefficient, the second image, and the time difference between acquiring the first image and acquiring the second image are multiplied to obtain the residual image caused by the scintillator of the flat panel detector when acquiring the second image, and the grayscale of the residual image at the ambient temperature when the flat panel detector acquires the first image, which can be expressed by the following formula:

[0079] Offset(x,y)=Pic_(T-1)(x,y)╳a t ╳△T;

[0080] Wherein, Offset(x,y) is the gray value corresponding to the pixel at position (x,y) in the residual image, Pic_(T-1)(x,y) is the gray value of the pixel at position (x,y) in the second image at ambient temperature (T-1), and a t is the light attenuation coefficient at the ambient temperature t when the first image is collected, and ΔT is the time difference between the time when the first image is collected and the time when the second image is collected.

[0081] After determining the grayscale of the afterimage at the ambient temperature when the flat panel detector acquires the first image, the grayscale can be used as the grayscale correction amount corresponding to the first image to perform afterimage correction on the first image. Specifically, the afterimage correction on the first image can be performed in the following manner:

[0082] A matrix difference operation is performed on the first image and the grayscale correction amount to obtain a corrected first image.

[0083] Each pixel in the first image is regarded as an element at the corresponding position in the matrix, and the grayscale value of the pixel is recorded as the value of the corresponding element in the matrix. Similarly, the grayscale correction amount can also be regarded as a matrix. Therefore, by performing a matrix difference operation on the two, the corrected first image can be obtained. After that, the corrected first image can be directly sent to the host computer or display for display. In this way, no matter what frequency the user collects images, the collected images will not be affected by the afterimage and distorted.

[0084] Based on the same inventive concept, an embodiment of the present invention provides a flat panel detector. The specific implementation of the afterimage correction method of the flat panel detector can be found in the description of the method embodiment part. The repeated parts will not be repeated. Please refer to Figure 2 , the flat panel detector comprises:

[0085] Flat panel detector panel 1;

[0086] A temperature sensor 2, arranged in the flat panel detector panel, for collecting the ambient temperature of the environment where the flat panel detector panel is located;

[0087] The programmable logic array FPGA3 is used to store a preset relationship for determining the light attenuation coefficient, collect a first image from the flat panel detector panel, obtain the current ambient temperature from the temperature sensor, and execute the flat panel detector afterimage correction method as described above.

[0088] In a possible implementation manner, the flat panel detector panel 1 includes:

[0089] A plurality of light emitting diodes arranged in a neat pattern, and thin film transistors corresponding to the plurality of light emitting diodes one by one;

[0090] The thin film transistor is reset during idle time, and at the same time, the electric field of the light emitting diode is reversed.

[0091] The flat panel detector can be an X-ray flat panel detector, which can be applied to medical imaging detection, industrial flaw detection, etc. For example, in the field of medical imaging, clinicians can take X-rays for patients without waiting for the light attenuation time, which reduces the waiting time of doctors and patients, and can achieve continuous image acquisition. Doctors can more accurately judge the patient's lesions through accurate image information; in the field of industrial exploration, it is convenient for engineers to accurately confirm the location and shape of the target; in the field of public safety, it assists security personnel to accurately find dangerous objects and ensure people's safety.

[0092] Based on the same inventive concept, see Figure 3 In one embodiment of the present invention, a detection system is provided, comprising:

[0093] The flat panel detector 10 as described above;

[0094] The host computer 20 is used to acquire images from the flat panel detector and display the images.

[0095] The host computer may be a computer with a display, or a server, an industrial computer, a portable computer, a tablet computer, etc.

[0096] Those skilled in the art will appreciate that the embodiments of the present invention may be provided as methods, systems, or program products. Therefore, the embodiments of the present invention may be in the form of complete hardware embodiments, complete software embodiments, or embodiments combining software and hardware. Moreover, the embodiments of the present invention may be in the form of machine program products implemented on one or more readable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer / processor available program codes.

[0097] The embodiments of the present invention are described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0098] These program instructions may also be stored in a readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the readable memory produce a manufactured product including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0099] These program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer / processor-implemented process, thereby providing instructions executed on the computer / processor or other programmable device for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0100] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for correcting residual image of a flat panel detector, characterized in that: The method comprises: Obtaining the time difference between the currently acquired first image and the last acquired second image; Determine, according to the relationship between the time difference and the light attenuation duration corresponding to the scintillator of the flat-panel detector, an afterimage caused by the scintillator when acquiring the second image, the grayscale of the afterimage at the ambient temperature when the flat-panel detector acquires the first image, and use the grayscale of the afterimage as the grayscale correction amount corresponding to the first image; Performing afterimage correction on the first image using the grayscale correction amount to obtain a corrected first image; Wherein, determining the afterimage caused by the scintillator of the flat panel detector when acquiring the second image according to the magnitude relationship between the time difference and the light attenuation duration corresponding to the scintillator, and the grayscale of the afterimage at the ambient temperature when the flat panel detector acquires the first image, comprises: If the time difference is greater than or equal to the light attenuation duration corresponding to the scintillator, the grayscale of the afterimage is 0; If the time difference is less than the light attenuation duration corresponding to the scintillator, the grayscale of the afterimage is determined according to the second image, the light attenuation coefficient corresponding to the second image, the ambient temperature, and the time difference.

2. The method according to claim 1, characterized in that Obtain the time difference between the current first image and the last second image, including: Acquire a first time of acquiring the first image; Acquire a second time for acquiring the second image; A difference operation is performed on the first time and the second time to obtain the time difference.

3. The method according to claim 1, characterized in that Determining the grayscale of the afterimage according to the second image, the light attenuation coefficient corresponding to the second image, the ambient temperature, and the time difference includes: The ambient temperature and the time difference are calculated using a preset relationship to determine the light attenuation coefficient; wherein the preset relationship is determined based on the first dark state image and the second dark state image corresponding to different interval lengths under different temperature conditions of the flat panel detector, the first dark state image is a dark state image collected after exposing the bright state image, and the second dark state image is a dark state image after the interval length is fitted based on the bright state image; Performing a product operation on the second image, the light attenuation coefficient, the current temperature, and the time difference to obtain a grayscale of the residual image; Wherein, the preset relationship is: ； Where, t is the test environment temperature, a t is the light attenuation coefficient at the test ambient temperature, Graylevel(1st) t Graylevel(n) is the grayscale value of the first dark state image at the test ambient temperature. t is the grayscale value of the second dark state image under the test environment temperature, and Time is the set duration.

4. The method according to claim 3, characterized in that The method for obtaining the preset relationship includes: Under different test environment temperatures, collecting the bright state image, and after exposing the bright state image, collecting the first dark state image; Fitting the grayscale value of the second dark-state image at the test environment temperature according to the bright-state image and at the interval time after the bright-state image is collected; The preset relationship is determined according to the grayscale value of the first dark state image, the grayscale value of the second dark state image, and the interval time.

5. The method according to any one of claims 1 to 4, characterized in that: Correcting the first image using the grayscale correction amount to obtain a corrected first image includes: A matrix difference operation is performed on the first image and the grayscale correction amount to obtain the corrected first image.

6. A flat panel detector, characterized in that: include: Flat panel detector panel; A temperature sensor, disposed in the flat panel detector panel, for collecting the ambient temperature of the environment where the flat panel detector panel is located; A programmable logic array FPGA is used to store a preset relationship for determining the light attenuation coefficient, collect a first image from the flat panel detector panel, and obtain the current ambient temperature from the temperature sensor to execute the method according to any one of claims 1 to 5.

7. The flat panel detector according to claim 6, characterized in that: The flat panel detector comprises: A plurality of light emitting diodes arranged in an array, and thin film transistors corresponding one by one to the plurality of light emitting diodes; The thin film transistor is reset during idle time, and at the same time, the electric field of the light emitting diode is reversed.

8. A detection system, characterized in that: include: The flat panel detector according to claim 6 or 7; The host computer is used to acquire images from the flat panel detector and display the images.

Images