Method and apparatus for correcting excess signals in an imaging system
View Patent ↗A method and apparatus for excess signal compensation in an imaging system is described. In one particular embodiment, the invention provides for non-linear background, offset (due to time dependent dark current) and/or lag (including constant, linear and non-linear terms, due to image persistence) corrections of large area, flat panel imaging sensors.
1. An apparatus, comprising:
an imager; and
a processor coupled with the imager and configured to:
estimate an excess signal based on a non-linear correction to a decay response model and a frame rate; and
compensate for the excess signal in the image frame of an imaging system;
wherein the frame rate is faster than one tenth of a frame per second.
2. The apparatus of claim 1 , wherein the correction to the decay response model comprises a non-linear time variant decay response model.
3. The apparatus of claim 1 , wherein the correction to the decay response model comprises a representation of a measured signal of the image frame, and wherein the frame rate comprises a frame rate of a measured signal of an image frame.
4. The apparatus of claim 1 , further comprising the processor configured to select the frame rate.
5. The apparatus of claim 1 , wherein the frame rate is faster than 10 frames per second.
6. The apparatus of claim 1 , wherein the non-linear correction comprises a model based on one of a frame rate, a time difference between a frame time of a reference image and of exposure, an integral for a function over time, indexing a lookup table, integration of a smooth curve fit of experimentally derived excess signal data as a function of time, or any combination thereof.
7. An apparatus, comprising:
an imager; and
a processor coupled with the imager and configured to:
estimate an excess signal based on a non-linear correction to a decay response model of a non-saturated frame of a measured signal of an image frame of an imaging system; and
compensate for the excess signal in the image frame using the estimated excess signal.
8. The apparatus of claim 7 , wherein correction to the decay response model comprises a non-linear time variant decay response model.
9. The apparatus of claim 7 , wherein the correction to the decay response model comprises a representation of a measured signal of the image frame.
10. An apparatus, comprising:
an imager; and
a processor coupled with the imager and configured to:
estimate an excess signal based on a non-linear time variant correction to a decay response model of a measured signal of an image frame of an imaging system; and
subtract the excess signal from the measured signal of the image frame.
11. An apparatus, comprising:
an imager; and
a processor coupled with the imager and configured to:
estimate an excess signal based on a non-linear correction to a decay response model of a measured signal of an image frame of an imaging system; and
compensate for the excess signal in the image frame, wherein estimating the excess signal further comprises selecting a first reference image frame and selecting a second reference image frame.
12. The apparatus of claim 11 , wherein estimating is further based on a difference between two lag frames.
13. The apparatus of claim 11 , wherein the correction to the decay response model comprises a non-linear time variant decay response model.
14. The apparatus of claim 11 , wherein the correction to the decay response model comprises a representation of a measured signal of the image frame.
15. A system, comprising:
an x-ray source;
an imager to receive x-rays generated by the source; and
a processor coupled with the imager and configured to:
estimate an excess signal based on a non-linear correction to a decay response model and a frame rate; and
compensate for the excess signal in the image frame of an imaging system;
wherein the frame rate is faster than one tenth of a frame per second.
16. The system of claim 15 , wherein the correction to the decay response model comprises a non-linear time variant decay response model.
17. The system of claim 15 , wherein the correction to the decay response model comprises a representation of a measured signal of the image frame, and wherein the frame rate comprises a frame rate of a measured signal of an image frame.
18. The systems of claim 15 , further comprising the processor configured to select the frame rate.
19. The system of claim 15 , wherein the frame rate is faster than 10 frames per second.
20. The system of claim 15 , wherein non-linear correction comprises a model based on one of a frame rate, a time difference between a frame time of a reference image and of exposure, an integral for a function over time, indexing a lookup table, integration of a smooth curve fit of experimentally derived excess signal data as a function of time, or any combination thereof.
21. A system, comprising:
an x-ray source;
an imager to receive x-rays generated by the source; and
a processor coupled with the imager and configured to:
estimate an excess signal based on a non-linear time variant correction to a decay response model of a measured signal of an image frame of an imaging system; and
subtract the excess signal from the measured signal of the image frame.
22. The system of claim 21 , wherein the correction to the decay response model comprises a representation of a measured signal of the image frame, and wherein the correction to a model comprises a frame rate of a measured signal of an image frame.
23. The system of claim 21 , further comprising the processor configured to select the frame rate.
24. The system of claim 21 , wherein the non-linear time variant correction comprises a model based on one of a frame rate, a time difference between a frame time of a reference image and of exposure, an integral for a function over time, indexing a lookup table, integration of a smooth curve fit of experimentally derived excess signal data as a function of time, or any combination thereof.