CN-122016878-A - Perovskite X-ray image acquisition system and method based on time domain signal processing

CN122016878ACN 122016878 ACN122016878 ACN 122016878ACN-122016878-A

Abstract

The invention relates to the technical field of signal processing, in particular to a perovskite X-ray image acquisition system and method based on time domain signal processing, comprising a ray source module, a detector module, an analog front end module, an ADC module, an FPGA module, a high-speed interface module and an upper computer module, wherein the ray source module is used for emitting photons, the detector module is used for collecting and integrating charges of the photons to obtain integrated node voltage in a pixel, the analog front end module is used for sampling the voltage of the integration node in the pixel to obtain a multichannel analog differential voltage, the ADC module is used for synchronously sampling and quantizing the multichannel analog differential voltage to obtain a pixel value sequence and a synchronous mark signal, the FPGA module is used for performing time domain signal processing to obtain an image frame and metadata, the high-speed interface module is used for packaging to obtain an Ethernet frame package, and the upper computer module is used for unpacking and displaying the Ethernet frame package to obtain a control signal. The invention improves the imaging quality and precision by adding the FPGA module.

Inventors

Niu guangda
Ling Qinghao
CHEN HAO

Assignees

华中科技大学
湖北光谷实验室

Dates

Publication Date: 20260512
Application Date: 20251212

Claims (10)

1. The perovskite X-ray image acquisition system based on time domain signal processing is characterized by comprising a ray source module (1), a detector module (2), an analog front end module (3), an ADC module (4), an FPGA module (5), a high-speed interface module (6) and an upper computer module (7), wherein, The ray source module (1) is used for emitting photons, transmitting an object to be imaged, attenuating the photons through the object to be imaged, obtaining attenuated photons, and sending the attenuated photons to the detector module (2); the detector module (2) is used for collecting and integrating charges of photons to obtain voltage of integration nodes in pixels and sending the voltage to the analog front-end module (3); the analog front-end module (3) is used for carrying out sample holding, resetting and correlated double sampling on the voltage of the integration node in the pixel to obtain a multichannel analog differential voltage and sending the multichannel analog differential voltage to the ADC module (4); The ADC module (4) is used for synchronously sampling and quantizing the multichannel analog differential voltage to obtain a pixel value sequence and a synchronous mark signal and sending the pixel value sequence and the synchronous mark signal to the FPGA module (5); The FPGA module (5) is used for performing time domain signal processing on the pixel value sequence and the synchronous mark signal to obtain image frames and metadata and sending the image frames and the metadata to the high-speed interface module (6); The high-speed interface module (6) is used for packaging the image frames and the metadata to obtain an Ethernet frame packet and sending the Ethernet frame packet to the upper computer module (7); the upper computer module (7) is used for unpacking and displaying the Ethernet frame package to obtain a control signal.
2. The perovskite X-ray image acquisition system based on time domain signal processing according to claim 1, wherein the FPGA module (5) comprises a data decoding module (51), a dynamic compensation module (52), a row-column readout noise correction module (53), a pixel-level time domain filtering module (54), an interframe fusion module (55) and an output encapsulation module (56).
3. The perovskite X-ray image acquisition system based on time domain signal processing as claimed in claim 2, wherein the data decoding module (51) is configured to perform channel alignment, row-column addressing and dead pixel replacement on the pixel value sequence and the synchronization mark signal to obtain a pixel value matrix.
4. A time domain signal processing based perovskite X-ray image acquisition system as claimed in claim 3 wherein the dynamic compensation module (52) is configured to map a matrix of pixel values from raw ADC code values to linear luminance code values while maintaining a slow variable baseline for each pixel and dynamically updating to obtain dynamically compensated pixel values.
5. The perovskite X-ray image acquisition system based on time domain signal processing as claimed in claim 4, wherein the row-column readout noise correction module (53) is configured to eliminate row-column fixed offsets introduced by readout links on a frame-by-frame basis for dynamically compensated pixel values, and recover global luminance baselines after subtracting row offsets from column offsets, to obtain corrected pixel values.
6. The perovskite X-ray image acquisition system based on time domain signal processing as claimed in claim 5, wherein the pixel level time domain filtering module (54) is configured to perform high pass slow drift and low pass high frequency suppression on each pixel of the corrected pixel value, respectively, to obtain a filtered real-time pixel stream.
7. The perovskite X-ray image acquisition system based on temporal signal processing as claimed in claim 6, wherein the interframe fusion module (55) is configured to enhance the signal-to-noise ratio of the filtered real-time pixel stream by adaptive exponential sliding temporal fusion and motion gating to obtain an enhanced visual pixel stream.
8. The time domain signal processing based perovskite X-ray image acquisition system as claimed in claim 7 wherein the output packaging module (56) is configured to statistically enhance saturation counts, means, variances, row and column residuals of the visual image pixel stream and record key parameters to obtain image frames and metadata.
9. The perovskite X-ray image acquisition system based on time domain signal processing as claimed in claim 8, wherein the control signals include tube voltage, tube current, integration time, analog gain, filter parameters and baseline step size, the control signals are applied to the FPGA module (5), the analog front-end module (3) and the radiation source module (1) through a control bus.
10. A perovskite X-ray image acquisition method based on time domain signal processing, implemented by using the perovskite X-ray image acquisition system based on time domain signal processing according to any one of claims 1 to 9, wherein the method comprises: the photon is emitted through the ray source module (1), penetrates through the object to be imaged, and is attenuated by the object to be imaged to obtain an attenuated photon; the attenuated photons are sent to a detector module (2) for charge collection and integration, and voltage of integration nodes in the pixels is obtained; Sending the voltage of the integration node in the pixel to an analog front-end module (3) for sampling, holding, resetting and correlated double sampling to obtain a multichannel analog differential voltage; Transmitting the multichannel analog differential voltage to an ADC module (4) for synchronous sampling quantization to obtain a pixel value sequence and a synchronous mark signal; Sending the pixel value sequence and the synchronous mark signal to an FPGA module (5) for time domain signal processing to obtain an image frame and metadata; transmitting the image frames and the metadata to a high-speed interface module (6) for packaging to obtain an Ethernet frame packet; And sending the Ethernet frame packet to an upper computer module (7) for unpacking and displaying to obtain a control signal.

Description

Perovskite X-ray image acquisition system and method based on time domain signal processing Technical Field The invention relates to the technical field of signal processing, in particular to a perovskite X-ray image acquisition system and method based on time domain signal processing. Background The perovskite direct conversion X-ray detector is becoming a potential core device for medical imaging and industrial nondestructive detection due to the advantages of high X-ray absorption efficiency, integration with a large-area readout array and the like. The true availability of imaging systems is not only dependent on device materials and pixel architecture, but is also greatly affected by time domain processing in the signal link. The key indicators for evaluating the comprehensive imaging capability of the detector are the detection quantum efficiency DQE and the modulation transfer function describing detail fidelity. The existing direct conversion area array is generally composed of detector pixel array, analog readout (integration/sample hold/CDS), ADC, digital processing/upper computer. To improve image quality, common methods include, but are not limited to, static dark field/gain correction (based on off-line or periodic calibration frames), spatial domain denoising (median/mean/bilateral filtering, non-local mean, etc.), line-column streak correction (line-by-line/column-by-column de-biasing, frequency domain streak suppression), inter-frame averaging (trade signal-to-noise ratio with time, sacrifice of time resolution). Although the prior art improves the image quality to a certain extent, the problems often exist that time domain statistics is not coupled with a DQE target, filtering parameters are selected empirically, the DQE is difficult to maximize around a target space frequency, MTF is kept for system optimization, dynamic distortion response is insufficient, dark current drift, gain nonlinearity/saturation and the like are changed along with dosage, temperature and time, static compensation is difficult to track in time, real-time implementation is difficult, complex space domain algorithms have large resource/bandwidth/time sequence pressure on an FPGA, and stable operation under high frame rate is difficult. Disclosure of Invention In view of the above, the invention provides a perovskite X-ray image acquisition system and method based on time domain signal processing, which realizes real-time processing in a full-link frame by adding an FPGA module, reduces the load of an upper computer by algorithm hardware, delays less than one frame period, and can adapt to rapid working condition change by online switching of parameters. By adopting the parallel of the localization and the DSP, the filtering/compensating calculation amount and the resource cost are controlled, the deployability of engineering is enhanced, higher image quality can be obtained under the condition of not increasing the dose, the radiation dose can be reduced equivalently to achieve the same diagnosis target, the irradiation of patients/samples is reduced, the dependence on extremely low-noise and extremely uniform expensive devices is reduced, the index of front-end devices is relaxed, the system image quality target can be achieved, and the cost is saved from the system level. In a first aspect, the invention provides a perovskite X-ray image acquisition system based on time domain signal processing, which comprises a ray source module, a detector module, an analog front end module, an ADC module, an FPGA module, a high-speed interface module and an upper computer module, wherein, The ray source module is used for emitting photons, transmitting the object to be imaged, attenuating the photons by the object to be imaged, obtaining attenuated photons, and transmitting the attenuated photons to the detector module; the detector module is used for collecting and integrating charges of photons to obtain voltage of integration nodes in pixels and sending the voltage to the analog front-end module; the analog front-end module is used for carrying out sampling, holding, resetting and correlated double sampling on the voltage of the integration node in the pixel to obtain a multichannel analog differential voltage and sending the multichannel analog differential voltage to the ADC module; The ADC module is used for synchronously sampling and quantizing the multichannel analog differential voltage to obtain a pixel value sequence and a synchronous mark signal and sending the pixel value sequence and the synchronous mark signal to the FPGA module; The FPGA module is used for performing time domain signal processing on the pixel value sequence and the synchronous mark signal to obtain an image frame and metadata and sending the image frame and metadata to the high-speed interface module; the high-speed interface module is used for packaging the image frames and the metadata to obtain an Ethernet frame packet and sending the Ethern