Imaging method using an image sensor with multiple radiation detectors

Abstract

Disclosed herein is a method comprising: taking, with radiation detectors (100) of an image sensor (490), part images of scene parts (i), i = 1,..., N, of a scene. For i = 1,..., N, Qi part images of the scene part (i) are taken by Qi radiation detectors (100) of the P radiation detectors (100), respectively, Qi being an integer greater than 1. The Qi part images are Qi part images of the part images. The method further comprises: for i = 1,..., N, generating, from the Qi part images of the scene part (i), an enhanced part image (i). Generating the enhanced part image (i) is based on positions and orientations of the Qi radiation detectors (100) relative to the image sensor and displacements between Qi imaging positions of the scene relative to the image sensor (490). The scene is at the Qi imaging positions when the Qi part images are taken by the Qi radiation detectors (100), respectively.

Description

Imaging methods using image sensors with multiple radiation detectors Background Technology

[0001] A radiation detector is a device for measuring the properties of radiation. Examples of properties can include the spatial distribution of the intensity, phase, and polarization of the radiation. The radiation can be radiation that has already interacted with an object. For example, the radiation measured by a radiation detector can be radiation that has already penetrated an object. The radiation can be electromagnetic radiation, such as infrared light, visible light, ultraviolet light, X-rays, or gamma rays. The radiation can also be other types, such as alpha rays and beta rays. Imaging systems can include image sensors with multiple radiation detectors. Summary of the Invention

[0002] This document discloses a method comprising: capturing M partial images of N scene portions (scene portions (i), i = 1, ..., N) of a scene using P radiation detectors of an image sensor, wherein M, N, and P are positive integers, and wherein for i = 1, ..., N, Qi partial images of the scene portion (i) are captured by Qi radiation detectors of the P radiation detectors, where Qi is an integer greater than 1, and wherein the Qi partial images are Qi partial images among the M partial images; and generating an enhanced partial image (i) from the Qi partial images of the scene portion (i) for i = 1, ..., N, wherein the generation of the enhanced partial image (i) is based on (A) the position and orientation of the Qi radiation detectors relative to the image sensor, and (B) the displacement between Qi imaging positions of the scene relative to the image sensor, wherein the scene is located at the Qi imaging positions when the Qi radiation detectors capture the Qi partial images respectively.

[0003] In one respect, at least two of the M partial images are captured simultaneously by the image sensor.

[0004] In one respect, the at least two partial images are captured by at least two of the P radiation detectors.

[0005] On the one hand, for i = 1, ..., N, Qi > 2.

[0006] On the one hand, N>1.

[0007] On the one hand, for i = 1, ..., N, Qi = P.

[0008] In one aspect, generating enhanced partial images (i) includes applying one or more super-resolution algorithms to the Qi partial images.

[0009] In one aspect, applying the one or more super-resolution algorithms to the Qi partial images includes aligning the Qi partial images.

[0010] In one aspect, the method also includes stitching together the enhanced portion image (i), i = 1, ..., N, to obtain a stitched image of the scene.

[0011] In one respect, the stitching is based on the position and orientation of at least one of the P radiation detectors relative to the image sensor.

[0012] In one aspect, the method further includes using a stepper motor to determine the displacement between the Qi imaging positions, the stepper motor including a mechanism for measuring the distance of movement caused by the stepper motor.

[0013] In one aspect, the method also includes using optical diffraction to determine the displacement between the Qi imaging positions.

[0014] In one aspect, the shooting includes moving the scene in a straight line relative to the image sensor throughout the entire shooting process.

[0015] On one hand, the scene does not reverse its direction of movement throughout the entire shooting process.

[0016] On the one hand, N > 1, j and k belong to 1, ..., N, j ≠ k, and the Qj radiation detectors are different from the Qk radiation detectors.

[0017] On the one hand, N>1, j and k belong to 1, ..., N, j≠k, and Qj≠Qk.

[0018] This paper discloses a method comprising: capturing M partial images of N scene parts (scene parts (i), i = 1, ..., N) of a scene using P radiation detectors of an image sensor, wherein M, N, and P are positive integers, and wherein, for i = 1, ..., N, Qi partial images of the scene part (i) are captured by Qi radiation detectors of the P radiation detectors, where Qi is an integer greater than 1, and wherein the Qi partial images are Qi partial images among the M partial images; and generating an enhanced partial image (i) from the Qi partial images of the scene part (i) for i = 1, ..., N.

[0019] In one aspect, the generation of the enhanced partial image (i) is based on (A) the displacement and relative orientation between the Qi radiation detectors relative to the image sensor, and (B) the displacement between the Qi imaging positions of the scene relative to the image sensor, wherein the scene is located at the Qi imaging positions when the Qi radiation detectors respectively capture the Qi partial images.

[0020] In one respect, at least two of the M partial images are captured simultaneously by the image sensor.

[0021] In one respect, the at least two partial images are captured by at least two of the P radiation detectors. Figure Description

[0022] Figure 1 schematically illustrates a radiation detector according to an embodiment.

[0023] Figure 2A schematically shows a simplified cross-sectional view of the radiation detector according to an embodiment.

[0024] Figure 2B schematically shows a detailed cross-sectional view of the radiation detector according to an embodiment.

[0025] Figure 2C schematically illustrates an alternative detailed cross-sectional view of the radiation detector according to an embodiment.

[0026] Figure 3 schematically shows a top view of a package including a radiation detector and a printed circuit board (PCB) according to an embodiment.

[0027] Figure 4 schematically shows a cross-sectional view of one of the packages of Figure 3 mounted to a system PCB according to an embodiment of an image sensor.

[0028] Figures 5A to 5N schematically illustrate the imaging process according to an embodiment.

[0029] Figures 6A and 6B schematically illustrate the image alignment process according to an embodiment.

[0030] Figure 7 is a flowchart summarizing and generalizing the imaging process according to the embodiments.

[0031] Figure 8 is another flowchart summarizing and generalizing the imaging process according to another embodiment. Detailed Implementation Methods

[0032] As an example, Figure 1 schematically illustrates a radiation detector 100. The radiation detector 100 includes an array of pixels 150 (also referred to as sensing elements 150). This array can be a rectangular array (as shown in Figure 1), a cellular array, a hexagonal array, or any other suitable array. The pixel 150 array in the example of Figure 1 has 4 rows and 7 columns; however, typically, the pixel 150 array can have any number of rows and any number of columns.

[0033] Each pixel 150 can be configured to detect radiation incident upon it from a radiation source (not shown) and can be configured to measure characteristics of the radiation (e.g., particle energy, wavelength, and frequency). The radiation can include particles, such as photons (electromagnetic waves) and subatomic particles. Each pixel 150 can be configured to count the number of radiant particles incident upon it over a period of time, with energy falling within multiple energy ranges. All pixels 150 can be configured to count the number of radiant particles incident upon it within multiple energy ranges simultaneously over the same period of time. When the incident radiant particles have similar energies, pixel 150 can simply be configured to count the number of radiant particles incident upon it over a period of time without measuring the energy of individual radiant particles.

[0034] Each pixel 150 may have its own analog-to-digital converter (ADC) configured to digitize an analog signal representing the energy of an incident radiating particle into a digital signal, or to digitize an analog signal representing the total energy of multiple incident radiating particles into a digital signal. Pixels 150 may be configured to operate in parallel. For example, while one pixel 150 is measuring an incident radiating particle, another pixel 150 may be waiting for the radiating particle to arrive. Pixels 150 do not necessarily need to be individually addressable.

[0035] The radiation detector 100 described herein can be applied to applications such as X-ray telescopes, X-ray mammography, industrial X-ray defect detection, X-ray microscopy or microradiography, X-ray casting inspection, X-ray non-destructive testing, X-ray weld inspection, and X-ray digital subtraction angiography. It may also be suitable to use the radiation detector 100 in place of photographic plates, photographic films, PSP plates, X-ray image intensifiers, scintillators, or other semiconductor X-ray detectors.

[0036] Figure 2A schematically illustrates a simplified cross-sectional view of the radiation detector of Figure 1 according to an embodiment, along line 2A-2A. More specifically, the radiation detector 100 may include a radiation absorbing layer 110 and an electronic device layer 120 (e.g., an ASIC) for processing or analyzing electrical signals generated in the radiation absorbing layer 110 by incident radiation. The radiation detector 100 may or may not include a scintillator (not shown). The radiation absorbing layer 110 may comprise a semiconductor material, such as silicon, germanium, GaAs, CdTe, CdZnTe, or combinations thereof. This semiconductor material may have a high-quality attenuation coefficient for the radiation of interest.

[0037] As an example, Figure 2B schematically shows a detailed cross-sectional view of the radiation detector of Figure 1 along line 2A-2A. More specifically, the radiation absorption layer 110 may include one or more diodes (e.g., pin or pn) formed by one or more discrete regions 114 of a first doped region 111 and a second doped region 113. The second doped region 113 may be separated from the first doped region 111 by an optional intrinsic region 112. The discrete regions 114 are separated from each other by either the first doped region 111 or the intrinsic region 112. The first doped region 111 and the second doped region 113 have opposite types of doping (e.g., region 111 is p-type and region 113 is n-type, or region 111 is n-type and region 113 is p-type). In the example of Figure 2B, each discrete region 114 of the second doped region 113 forms a diode with the first doped region 111 and the optional intrinsic region 112. That is, in the example of FIG2B, the radiation absorption layer 110 has multiple diodes (more specifically, seven diodes correspond to seven pixels 150 in a row of the array in FIG1; for simplicity, only two of the pixels 150 are labeled in FIG2B). The multiple diodes have an electrode 119A as a common electrode. The first doped region 111 may also have discrete portions.

[0038] Electronics layer 120 may include electronic systems 121 suitable for processing or interpreting signals generated by radiation incident on radiation-absorbing layer 110. Electronic systems 121 may include analog circuitry such as filter networks, amplifiers, integrators, and comparators, or digital circuitry such as microprocessors and memories. Electronic systems 121 may include one or more ADCs. Electronic systems 121 may include components shared by pixels 150 or components dedicated to a single pixel 150. For example, electronic systems 121 may include amplifiers dedicated to each pixel 150 and microprocessors shared among all pixels 150. Electronic systems 121 may be electrically connected to pixels 150 via vias 131. The space between vias may be filled with filler material 130, which may increase the mechanical stability of the connection between electronics layer 120 and radiation-absorbing layer 110. Other bonding techniques may connect electronics 121 to pixels 150 without using vias 131.

[0039] When radiation from a radiation source (not shown) impacts the radiation-absorbing layer 110 of a diode, the radiation particles can be absorbed and generate one or more charge carriers (e.g., electrons, holes) through various mechanisms. The charge carriers can drift to an electrode of one of the diodes under an electric field. This field can be an external electric field. Electrical contacts 119B can include discrete portions, each of which is in electrical contact with a discrete region 114. The term "electrical contact" is used interchangeably with the term "electrode." In embodiments, charge carriers can drift in various directions such that charge carriers generated by a single radiation particle are substantially not shared by two different discrete regions 114 (here, "substantially not shared" means that less than 2%, less than 0.5%, less than 0.1%, or less than 0.01% of these charge carriers flow to a different discrete region 114 compared to the remaining charge carriers). Charge carriers generated by radiation particles incident around a coverage area of ​​one of these discrete regions 114 are substantially not shared with the other of these discrete regions 114. Pixel 150 associated with discrete region 114 can be a region surrounding discrete region 114 in which substantially all (greater than 98%, greater than 99.5%, greater than 99.9%, or greater than 99.99%) of the charge carriers generated by incident radiating particles flow to discrete region 114. That is, less than 2%, less than 1%, less than 0.1%, or less than 0.01% of these charge carriers flow through pixel 150.

[0040] Figure 2C schematically illustrates an alternative detailed cross-sectional view of the radiation detector 100 of Figure 1 according to an embodiment, along line 2A-2A. More specifically, the radiation absorbing layer 110 may comprise resistors made of semiconductor materials such as silicon, germanium, GaAs, CdTe, CdZnTe, or combinations thereof, but not diodes. This semiconductor material may have a high-quality attenuation coefficient for the radiation of interest. In an embodiment, the electronics layer 120 of Figure 2C is structurally and functionally similar to the electronics layer 120 of Figure 2B.

[0041] When radiation impacts the radiation-absorbing layer 110, which includes resistors but not diodes, it can be absorbed and generate one or more charge carriers through various mechanisms. The radiating particle can generate 10 to 100,000 charge carriers. These charge carriers can drift to electrical contacts 119A and 119B under an electric field. This electric field can be an external electric field. Electrical contact 119B includes discrete portions. In an embodiment, charge carriers can drift in various directions such that charge carriers generated by a single radiating particle are substantially not shared by the two distinct discrete portions of electrical contact 119B (here, "substantially not shared" means that less than 2%, less than 0.5%, less than 0.1%, or less than 0.01% of these charge carriers flow to a different discrete portion compared to the remaining charge carriers). Charge carriers generated by radiating particles incident on the coverage area of ​​one of these discrete portions of electrical contact 119B are substantially not shared with the other of these discrete portions of electrical contact 119B. Pixel 150 associated with a discrete portion of electrical contact 119B can be a region surrounding the discrete portion, in which substantially all (greater than 98%, greater than 99.5%, greater than 99.9%, or greater than 99.99%) of the charge carriers generated by incident radiant particles flow toward the discrete portion of electrical contact 119B. That is, less than 2%, less than 0.5%, less than 0.1%, or less than 0.01% of these charge carriers flow through a pixel associated with a discrete portion of electrical contact 119B.

[0042] Figure 3 schematically illustrates a top view of a package 200 including a radiation detector 100 and a printed circuit board (PCB) 400. The term "PCB" as used herein is not limited to a particular material. For example, a PCB may include semiconductors. The radiation detector 100 may be mounted to the PCB 400. For clarity, wiring between the detector 100 and the PCB 400 is not shown. The PCB 400 may have one or more radiation detectors 100. The PCB 400 may have an area 405 not covered by the radiation detector 100 (e.g., for accommodating bonding wires 410). The radiation detector 100 may have an effective area 190 where pixel 150 (Figure 1) is located. The radiation detector 100 may have a peripheral area 195 near the edge of the radiation detector 100. The peripheral area 195 does not contain pixel 150, and the radiation detector 100 does not detect radiation particles incident on the peripheral area 195.

[0043] Figure 4 schematically illustrates a cross-sectional view of an image sensor 490 according to an embodiment. The image sensor 490 may include multiple packages 200 of Figure 3 mounted to a system PCB 450. As an example, only two packages 200 are shown in Figure 4. The electrical connection between the PCB 400 and the system PCB 450 can be achieved via bonding wires 410. To accommodate the bonding wires 410 on the PCB 400, the PCB 400 may have a region 405 not covered by the detector 100. To accommodate the bonding wires 410 on the system PCB 450, there may be gaps between the packages 200. The gaps may be greater than about 1 mm. Radiation particles incident on the peripheral region 195, region 405, or gaps cannot be detected by the packages 200 on the system PCB 450. The dead zone of a radiation detector (e.g., radiation detector 100) is the area on the radiation receiving surface of the radiation detector that cannot be detected by the radiation detector. The dead zone of a package (e.g., package 200) is the area on which incident radiation particles on the radiation-receiving surface of the package cannot be detected by one or more detectors within the package. In the example shown in Figures 3 and 4, the dead zone of package 200 includes peripheral area 195 and area 405. The dead zone (e.g., image sensor 490) of an image sensor having a set of packages (e.g., packages 200 mounted on the same PCB, packages 200 arranged in the same layer) includes a combination of the dead zones of each package in the set and the gaps between the packages.

[0044] The image sensor 490, including the radiation detector 100, may have a dead zone 488 that cannot detect incident radiation. However, the image sensor 490 can capture local images of all points of an object or scene (not shown), and these captured local images can then be stitched together to form a complete image of the entire object or scene.

[0045] Figures 5A to 5N schematically illustrate an imaging session using the image sensor 490 of Figure 4 according to an embodiment. Referring to Figure 5A, in an embodiment, the image sensor 490 can be used to scan a scene 510. The image sensor 490 may include two radiation detectors 100a and 100b (similar to radiation detector 100), which may each include effective regions 190a and 190b. For simplicity, only the effective regions 190a and 190b of the image sensor 490 are shown, while other portions of the image sensor 490 are omitted. In an embodiment, the radiation detectors 100a and 100b of the image sensor 490 may be identical.

[0046] For illustrative purposes, object 512 (two swords) may be part of scene 510. In an embodiment, scene 510 may include four scene sections 510.1, 510.2, 510.3, and 510.4. In an embodiment, scene 510 may move from left to right while image sensor 490 scans scene 510, keeping image sensor 490 stationary.

[0047] Specifically, in an embodiment, scene 510 may begin at a first imaging position in which scene portion 510.1 is aligned with effective region 190a (FIG. 5A). In an embodiment, while scene 510 remains stationary at the first imaging position, effective region 190a may capture a partial image 520a1 of scene portion 510.1 (FIG. 5B).

[0048] Next, in this embodiment, scene 510 can be further moved to the right to a second imaging position where scene portion 510.2 is aligned with the effective area 190a (Figure 5C). In this embodiment, while scene 510 remains stationary at the second imaging position, the effective area 190a can capture a partial image 520a2 of scene portion 510.2 (Figure 5D).

[0049] Next, in this embodiment, scene 510 can be further moved to the right to a third imaging position where scene portion 510.3 is aligned with the effective area 190a (Fig. 5E). In this embodiment, while scene 510 remains stationary at the third imaging position, the effective area 190a can capture a partial image 520a3 of scene portion 510.3 (Fig. 5F).

[0050] Next, in this embodiment, scene 510 can be further moved to the right to a fourth imaging position (Figure 5G) where scene portion 510.4 is aligned with effective region 190a and scene portion 510.1 is aligned with effective region 190b. In this embodiment, while scene 510 remains stationary at the fourth imaging position, effective regions 190a and 190b can simultaneously capture partial images 520a4 and 520b1 of scene portions 510.4 and 510.1, respectively (Figure 5H).

[0051] Next, in this embodiment, scene 510 can be further moved to the right to a fifth imaging position where scene portion 510.2 is aligned with the effective area 190b (Fig. 5I). In this embodiment, while scene 510 remains stationary at the fifth imaging position, the effective area 190b can capture a partial image 520b2 of scene portion 510.2 (Fig. 5J).

[0052] Next, in this embodiment, scene 510 can be further moved to the right to a sixth imaging position (Fig. 5K) where scene portion 510.3 is aligned with the effective area 190b. In this embodiment, while scene 510 remains stationary at the sixth imaging position, the effective area 190b can capture a partial image 520b3 of scene portion 510.3 (Fig. 5L).

[0053] Next, in this embodiment, scene 510 can be further moved to the right to a seventh imaging position (Fig. 5M) where scene portion 510.4 is aligned with the effective area 190b. In this embodiment, while scene 510 remains stationary at the seventh imaging position, the effective area 190b can capture a partial image 520b4 of scene portion 510.4 (Fig. 5N).

[0054] Summarizing the imaging session described above, referring to Figures 5A to 5N, each of the effective regions 190a and 190b is scanned through all four scene portions 510.1, 510.2, 510.3, and 510.4. In other words, each of the scene portions 510.1, 510.2, 510.3, and 510.4 has an image captured by both effective regions 190a and 190b. Specifically, scene portion 510.1 has images 520a1 and 520b1 captured by effective regions 190a and 190b, respectively. Scene portion 510.2 has images 520a2 and 520b2 captured by effective regions 190a and 190b, respectively. Scene portion 510.3 has images 520a3 and 520b3 captured by effective regions 190a and 190b, respectively. Scene section 510.4 has images 520a4 and 520b4 captured by effective areas 190a and 190b, respectively.

[0055] In an embodiment, referring to Figures 5A to 5N, for scene portion 510.1, a first enhanced partial image (not shown) of scene portion 510.1 can be generated from partial images 520a1 and 520b1 of scene portion 510.1. In an embodiment, the resolution of the first enhanced partial image can be higher than the resolution of partial images 520a1 and 520b1. For example, the resolution of the first enhanced partial image can be twice the resolution of partial images 520a1 and 520b1. Specifically, partial images 520a1 and 520b1 can each have 28 image elements (Figure 1), while the first enhanced partial image can have 2 × 28 = 56 image elements.

[0056] In an embodiment, a first enhanced partial image can be generated from partial images 520a1 and 520b1 by applying one or more super-resolution algorithms to partial images 520a1 and 520b1. Figures 6A and 6B illustrate how, according to an embodiment, one or more super-resolution algorithms can be applied to partial images 520a1 and 520b1 to obtain the first enhanced partial image.

[0057] Specifically, Figure 6A shows scene 510 at a first imaging position (the left half of Figure 6A, where the effective area 190a captures a partial image 520a1 of scene portion 510.1), and then shortly thereafter at a fourth imaging position (the right half of Figure 6A, where the effective area 190b captures a partial image 520b1 of scene portion 510.1). For simplicity, only scene portion 510.1 of scene 510 is shown (i.e., the other three scene portions 510.2, 510.3, and 510.4 of scene 510 are not shown).

[0058] On one hand, in an embodiment, the position and orientation of radiation detectors 100a and 100b relative to image sensor 490 can be determined. Thus, the displacement and relative orientation between radiation detectors 100a and 100b relative to image sensor 490 can be determined. In an embodiment, these determinations can be performed by the manufacturer of image sensor 490, and the resulting determination data can be stored in image sensor 490 for later use in subsequent imaging sessions that include the aforementioned imaging session.

[0059] On the other hand, in an embodiment, during the aforementioned imaging session, a stepper motor (not shown) can be used to move scene 510 from a first imaging position through second and third imaging positions to a fourth imaging position. In an embodiment, the stepper motor may include a mechanism for measuring the distance traveled by the stepper motor. For example, electrical pulses can be sent to the stepper motor to determine the displacement of scene 510. Thus, the displacement between the first and fourth imaging positions relative to image sensor 490 can be determined. Alternatively, instead of using a stepper motor with a mechanism for measuring distance, optical diffraction can be used to determine the displacement between the first and fourth imaging positions relative to image sensor 490. Generally, any method used to determine the distance traveled by scene 510 relative to image sensor 490 can be used to determine the displacement between the first and fourth imaging positions relative to image sensor 490.

[0060] As a simplified example, assume that the positions and orientations of radiation detectors 100a and 100b relative to image sensor 490 are determined. Thus, (A) the displacement between radiation detectors 100a and 100b in the eastward direction is determined to be 12 sensing element widths (i.e., 12 times the width 102 of sensing element 150 in FIG. 1), and (B) the relative orientation between radiation detectors 100a and 100b is zero. In other words, radiation detector 100a will need to translate (without rotation) a distance of 12 sensing element widths in the eastward direction to reach and coincide with radiation detector 100b.

[0061] Furthermore, in the simplified example, it is further assumed that the displacement between the first and fourth imaging positions relative to the image sensor 490 in the eastward direction is determined to be 11.3 sensing element widths. In other words, scene 510 moves a distance of 11.3 sensing element widths in the eastward direction to reach the fourth imaging position.

[0062] As a result, in the simplified example, as shown in Figure 6B, when the two partial images 520a1 and 520b1 are aligned such that the points of the scene portion 510.1 in partial images 520a1 and 520b1 overlap, the 28 image elements 150b' of partial image 520b1 are shifted to the right of the 28 image elements 150a' of partial image 520a1, with an offset 610 of 0.7 (i.e., 12-11.3) sensor element widths. In Figure 6B, for simplicity, the portion of partial image 520b1 that overlaps with partial image 520a1 is not shown.

[0063] In an embodiment, given an offset of 610 (i.e., 0.7 times the width of the sensing element), one or more super-resolution algorithms can be applied to portions of images 520a1 and 520b1 based on the determined offset of 610 to obtain a first enhanced portion image of scene portion 510.1.

[0064] The above description is a simplified example in which radiation detector 100a needs to be translated to reach and coincide with radiation detector 100b. Typically, to reach and coincide with radiation detector 100b, radiation detector 100a may need to both translate and rotate simultaneously. This means that the orientations of radiation detectors 100a and 100b relative to image sensor 490 are different, or in other words, the relative orientation between radiation detectors 100a and 100b is not zero.

[0065] Furthermore, under normal circumstances, the displacement between the first and fourth imaging positions relative to the image sensor 490 can be in a direction different from the eastward direction. However, under normal circumstances, with sufficient information (i.e., (A) the position and orientation of radiation detectors 100a and 100b relative to the image sensor 490, and (B) the displacement between the first and fourth imaging positions relative to the image sensor 490), partial images 520a1 and 520b1 can be aligned in a manner similar to that described above in the simplified example.

[0066] In summary, given the positions and orientations of radiation detectors 100a and 100b relative to image sensor 490, and the displacement between the first and fourth imaging positions relative to image sensor 490, partial images 520a1 and 520b1 can be aligned, and the offset 610 between image elements 150a' and 150b' can be determined. As a result, one or more super-resolution algorithms can be applied to partial images 520a1 and 520b1 based on the determined offset 610 between image elements 150a' and 150b', thereby obtaining a first enhanced partial image of scene portion 510.1.

[0067] In an embodiment, a second enhanced partial image of scene portion 510.2 can be generated from partial images 520a2 and 520b2 in a similar manner; a third enhanced partial image of scene portion 510.3 can be generated from partial images 520a3 and 520b3 in a similar manner; and a fourth enhanced partial image of scene portion 510.4 can be generated from partial images 520a4 and 520b4 in a similar manner.

[0068] Figure 7 is a flowchart 700 summarizing and generalizing the above-described imaging session (Figures 5A to 5N) according to an embodiment. Specifically, in step 710, M partial images (e.g., M = 8 partial images 520a1, 520a2, 520a3, 520a4, 520b1, 520b2, 520b3, and 520b4) of N scene parts (scene parts (i), i = 1, ..., N) of a scene (e.g., scene 510) (e.g., N = 4 scene parts 510.1, 510.2, 510.3, and 510.4) are captured by P radiation detectors (e.g., P = 2 radiation detectors 100a and 100b) of an image sensor (e.g., image sensor 490).

[0069] Furthermore, for i = 1, ..., N, the Qi partial images of scene part (i) (e.g., scene part 510.1) (e.g., in the case of i = 1, Q1 = 2 partial images 520a1 and 520b1) are captured by Qi radiation detectors (e.g., Q1 = 2 radiation detectors 100a and 100b) out of P radiation detectors. Additionally, the Qi partial images (e.g., in the case of i = 1, Q1 = 2 partial images 520a1 and 520b1) are Qi partial images out of M partial images (e.g., M = 8 partial images 520a1, 520a2, 520a3, 520a4, 520b1, 520b2, 520b3, and 520b4).

[0070] Next, in step 720, for i = 1, ..., N, an enhanced partial image (i) is generated from the Qi partial images of scene part (i) (e.g., scene part 510.1) (e.g., from the Q1 = 2 partial images 520a1 and 520b1) (e.g., in the case of i = 1, a first enhanced partial image is generated). Furthermore, the enhanced partial image (i) is generated based on (A) the position and orientation of the Qi radiation detectors (e.g., in the case of i=1, Q1=2 radiation detectors 100a and 100b) relative to the image sensor, and (B) the displacement between the Qi imaging positions (e.g., the first imaging position and the fourth imaging position) relative to the scene (e.g., scene 510) of the image sensor, wherein the scene is located at the Qi imaging positions when the Qi radiation detectors respectively capture the Qi partial images (e.g., when Q1=2 radiation detectors 100a and 100b capture Q1=2 partial images 520a1 and 520b1 respectively, scene 510 is located at the first imaging position and the fourth imaging position).

[0071] In an embodiment, referring to flowchart 700 of FIG7, at least two partial images of M partial images are captured simultaneously by an image sensor. For example, referring to FIGS. 5G to 5H, two partial images 520a4 and 520b1 are captured simultaneously by two radiation detectors 100a and 100b, respectively.

[0072] In an embodiment, referring to flowchart 700 of FIG7, the capturing process may include moving the scene in a straight line relative to the image sensor throughout the capturing process, wherein the scene does not reverse its direction of movement throughout the capturing process. For example, referring to FIGS. 5A to 5N, scene 510 moves in a straight line in the eastward direction relative to image sensor 490 and does not move in the westward direction at any time during the scanning of scene 510.

[0073] In the embodiment, referring to flowchart 700 of FIG7, for i = 1, ..., N, Qi can be equal to P. For example, in the imaging session described above, Q1 = Q2 = Q3 = Q4 = P = 2. In other words, each of the four scene portions 510.1, 510.2, 510.3, and 510.4 is scanned by each of P = 2 radiation detectors 100a and 100b.

[0074] In an embodiment, the first, second, third, and fourth enhanced partial images can be stitched together to obtain a stitched image (not shown) of scene 510 (Figures 5A to 5M). In an embodiment, the stitching of the first, second, third, and fourth enhanced partial images can be based on the position and orientation of at least one of the radiation detectors 100a and 100b relative to the image sensor 490. For example, the stitching of the first, second, third, and fourth enhanced partial images can be based on the position and orientation of the radiation detector 100a.

[0075] Figure 8 is a flowchart 800 summarizing and generalizing the imaging session described above (Figures 5A to 5N) according to an alternative embodiment. Specifically, in step 810, M partial images (e.g., M = 8 partial images 520a1, 520a2, 520a3, 520a4, 520b1, 520b2, 520b3, and 520b4) of N scene portions (scene portions (i), i = 1, ..., N) of a scene (e.g., scene 510) (e.g., N = 4 scene portions 510.1, 510.2, 510.3, and 510.4) are captured using P radiation detectors (e.g., P = 2 radiation detectors 100a and 100b) of an image sensor (e.g., image sensor 490).

[0076] Furthermore, for i = 1, ..., N, the Qi partial images of scene part (i) (e.g., scene part 510.1) (e.g., in the case of i = 1, Q1 = 2 partial images 520a1 and 520b1) are captured by Qi radiation detectors out of P radiation detectors (e.g., Q1 = 2 radiation detectors 100a and 100b). Additionally, the Qi partial images (e.g., in the case of i = 1, Q1 = 2 partial images 520a1 and 520b1) are among M partial images (e.g., M = 8 partial images 520a1, 520a2, 520a3, 520a4, 520b1, 520b2, 520b3, and 520b4).

[0077] Next, in step 820, for i = 1, ..., N, an enhanced partial image (i) is generated from the Qi partial images of scene part (i) (e.g., scene part 510.1) (e.g., from the Q1 = 2 partial images 520a1 and 520b1) (e.g., in the case of i = 1, a first enhanced partial image is generated).

[0078] In the above embodiments, referring to Figures 5A to 5N, the image sensor 490 remains stationary while the scene 510 (along with the object 512) moves. Alternatively, while the image sensor 490 scans the scene 510, the scene (along with the object 512) can remain stationary while the image sensor 490 (along with the radiation detectors 100a and 100b) can move.

[0079] In the above embodiment, the image sensor 490 includes two radiation detectors 100a and 100b. Typically, the image sensor 490 may include any number of radiation detectors 100. Furthermore, each of the four scene portions 510.1, 510.2, 510.3, and 510.4 does not necessarily need to have images captured by all the radiation detectors of the image sensor 490. Moreover, each of the four scene portions 510.1, 510.2, 510.3, and 510.4 does not necessarily need to have an image captured by the same radiation detector.

[0080] For example, assume that image sensor 490 includes radiation detectors 100a, 100b, and a third radiation detector (not shown, but similar to radiation detector 100). Then, in an embodiment, scene portion 510.1 may have two images captured by radiation detectors 100a and 100b, respectively; scene portion 510.2 may have two images captured by radiation detectors 100a and the third radiation detector, respectively; scene portion 510.3 may have two images captured by radiation detectors 100b and the third radiation detector, respectively; and scene portion 510.4 may have three images captured by all the radiation detectors (100a, 100b, and the third radiation detector), respectively.

[0081] In the above embodiment, the position and orientation of radiation detectors 100a and 100b relative to image sensor 490 are used to help align portions of images 520a1 and 520b1 (FIG. 7, step 720, part (A)). Alternatively, the displacement and relative orientation between radiation detectors 100a and 100b relative to image sensor 490 can be used instead of the position and orientation of radiation detectors 100a and 100b to help align portions of images 520a1 and 520b1. Specifically, as shown in the simplified example above, a displacement of 12 sensing element widths in the eastward direction between radiation detectors 100a and 100b relative to image sensor 490 and a zero relative orientation between radiation detectors 100a and 100b are used to help determine offset 610 (i.e., to help align portions of images 520a1 and 520b1).

[0082] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for illustrative purposes and are not intended to be limiting; the true scope and spirit are indicated by the appended claims.

Claims

1. An imaging method, comprising: M partial images of N scene portions are captured using P radiation detectors of an image sensor, where M, N, and P are positive integers, and N > 1. For i = 1, ..., N, Qi partial images of the i-th scene portion are captured by Qi radiation detectors from the P radiation detectors, where Qi is an integer greater than 1, and the Qi partial images are the Qi partial images from the M partial images. For i = 1, ..., N, enhanced partial images are generated from the Qi partial images of the i-th scene portion. The generation of enhanced partial images is based on the position and orientation of the Qi radiation detectors relative to the image sensor, and the displacement between the Qi imaging positions of the scene relative to the image sensor. When the Qi radiation detectors capture the Qi partial images, the scene is located at the Qi imaging positions. The generation of enhanced partial images includes applying one or more super-resolution algorithms to the Qi partial images.

2. The method according to claim 1, wherein, At least two of the M partial images are captured simultaneously by the image sensor.

3. The method according to claim 2, wherein, The at least two partial images are captured by at least two of the P radiation detectors.

4. The method according to claim 1, wherein, For i = 1, ..., N, Qi > 2.

5. The method according to claim 1, wherein, For i = 1, ..., N, Qi = P.

6. The method according to claim 1, wherein, The P radiation detectors are identical.

7. The method according to claim 6, wherein, Applying the one or more super-resolution algorithms to the Qi partial images includes aligning the Qi partial images.

8. The method according to claim 1 further includes stitching together N of the enhanced partial images to obtain a stitched image of the scene.

9. The method according to claim 8, wherein, The stitching is based on the position and orientation of at least one of the P radiation detectors relative to the image sensor.

10. The method of claim 1, further comprising using a stepper motor to determine the displacement between the Qi imaging positions, the stepper motor including a mechanism for measuring the distance of movement caused by the stepper motor.

11. The method of claim 1, further comprising using optical diffraction to determine the displacement between the Qi imaging positions.

12. The method according to claim 1, wherein, The shooting involves moving the scene in a straight line relative to the image sensor throughout the entire shooting process.

13. The method according to claim 12, wherein, The scene does not reverse its direction of movement throughout the entire shooting process.

14. The method according to claim 1, wherein N > 1, wherein j and k belong to 1, ..., N, wherein j ≠ k, and wherein Qj radiation detectors are different from Qk radiation detectors.

15. The method according to claim 1, wherein N>1, wherein j and k belong to 1, ..., N, wherein j≠k, and wherein Qj≠Qk.

16. An imaging method, comprising: M partial images of N scene parts are captured using P radiation detectors of an image sensor, where M, N, and P are positive integers, and N > 1. For i = 1, ..., N, Qi partial images of the i-th scene part are captured by Qi radiation detectors of the P radiation detectors, where Qi is an integer greater than 1, and the Qi partial images are the Qi partial images among the M partial images. For i = 1, ..., N, enhanced partial images are generated from the Qi partial images of the i-th scene part, wherein generating enhanced partial images includes applying one or more super-resolution algorithms to the Qi partial images.

17. The method according to claim 16, wherein, At least two of the M partial images are captured simultaneously by the image sensor.

18. The method according to claim 17, wherein, The at least two partial images are captured by at least two of the P radiation detectors.

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