INFERENCE OF BRIGHT FLAT-FIELD CORRECTION BASED ON SCAN RADIOGRAPHS
Systems, methods, apparatuses, and computer program products for nonintrusive scanning of objects using X-ray electromagnetic radiation. One method can include generating at least one two-dimensional X-ray radiograph image; generating synthetic flat field data using the at least one two-dimensional X-ray radiograph image, a second two-dimensional X-ray radiograph image, or both; and applying flat field image correction using the synthetic flat field data to the at least one two-dimensional X-ray radiograph image.
1 . A method of flat field image correction, comprising:
generating at least one two-dimensional X-ray radiograph image;
generating synthetic flat field data using the at least one two-dimensional X-ray radiograph image, a second two-dimensional X-ray radiograph image, or both; and
applying flat field image correction using the synthetic flat field data to the at least one two-dimensional X-ray radiograph image.
2 . The method of claim 1 , wherein generating the synthetic flat field data comprises generating the synthetic flat field data using at least the second two-dimensional X-ray radiograph image of a scan object that is partially out of a field of view of an X-ray scanner that scans the scan object.
3 . The method of claim 1 , wherein generating the synthetic flat field data comprises:
generating a two-dimensional image comprising background pixels that do not include a scan object, wherein the background pixels of the two-dimensional image are generated using one or more background pixels in the at least one two-dimensional X-ray radiograph image, the second two-dimensional X-ray radiograph image, or both;
fitting an inverse paraboloid function to the background pixels of the two-dimensional image; and
generating the synthetic flat field data using the inverse paraboloid function fit to the background pixels of the two-dimensional image.
4 . The method of claim 3 , wherein a pixel value of a background pixel of the two-dimensional image is an average of values of corresponding background pixels in at least two radiograph images.
5 . The method of claim 1 , wherein the synthetic flat field data comprises data generated from the second two-dimensional X-ray radiograph image that is collected under a different scanner condition than a scanner condition under which the at least one two-dimensional X-ray radiograph image is collected.
6 . The method of claim 1 , wherein the synthetic flat field data comprises data generated from stitched data.
7 . The method of claim 1 , wherein the synthetic flat field data comprises data generated from a plurality of radiograph images collected under a plurality of scanner conditions.
8 . The method of claim 7 , wherein generating the synthetic flat field data comprises generating the synthetic flat field data by assembling the plurality of radiograph images collected under the plurality of scanner conditions.
9 . The method of claim 1 , wherein the synthetic flat field data comprises inferred synthetic flat field data.
10 . The method of claim 9 , wherein the inferred synthetic flat field data comprises data inferred from at least one portion of a radiograph for empty field, and a predefined property associated with a representative field.
11 . The method of claim 1 , wherein the synthetic flat field data comprises at least one dark field image, at least one bright field image, or a combination thereof.
12 . The method of claim 1 , wherein the synthetic flat field data is associated with at least one of a low brightness condition, a low sensitivity condition, and a time of day condition.
13 . The method of claim 1 , wherein the synthetic flat field data comprises at least one pixel linearly sensitive to visible light.
14 . The method of claim 1 , wherein the synthetic flat field data is configured for pixelated correction.
15 . A system comprising:
an X-ray scanner; and
a computer communicatively coupled with the X-ray scanner, wherein the computer comprises a hardware processor and a non-transitory computer-readable medium encoding instructions configured to cause the hardware processor to perform operations comprising:
receiving or generating at least one two-dimensional X-ray radiograph image from or using the X-ray scanner,
generating synthetic flat field data using the at least one two-dimensional X-ray radiograph image, a second two-dimensional X-ray radiograph image, or both, and
applying flat field image correction using the synthetic flat field data to the at least one two-dimensional X-ray radiograph image.
16 . The system of claim 15 , wherein generating the synthetic flat field data comprises generating the synthetic flat field data using at least the second two-dimensional X-ray radiograph image of a scan object that is partially out of a field of view of the X-ray scanner that scans the scan object.
17 . The system of claim 15 , wherein generating the synthetic flat field data comprises:
generating a two-dimensional image comprising background pixels that do not include a scan object, wherein the background pixels of the two-dimensional image are generated using one or more background pixels in the at least one two-dimensional X-ray radiograph image, the second two-dimensional X-ray radiograph image, or both;
fitting an inverse paraboloid function to the background pixels of the two-dimensional image; and
generating the synthetic flat field data using the inverse paraboloid function fit to the background pixels of the two-dimensional image.
18 . The system of claim 17 , wherein a pixel value of a background pixel of the two-dimensional image is an average of values of corresponding background pixels in at least two radiograph images.
19 . The system of claim 15 , wherein the synthetic flat field data comprises data generated from the second two-dimensional X-ray radiograph image that is collected under a different scanner condition than a scanner condition under which the at least one two-dimensional X-ray radiograph image is collected.
20 . A non-transitory computer-readable medium encoding instructions operable to cause a data processing apparatus to perform operations comprising:
generating at least one two-dimensional X-ray radiograph image;
generating synthetic flat field data using the at least one two-dimensional X-ray radiograph image, a second two-dimensional X-ray radiograph image, or both; and
applying flat field image correction using the synthetic flat field data to the at least one two-dimensional X-ray radiograph image.