Methods, systems, and computer-program products for estimating scattered radiation in radiographic projections

A method of estimating scattered radiation in a radiographic projection of an object, the radiographic projection generated by an imaging device irradiated by a radiation source spaced therefrom to provide a space for the object, the imaging device measuring incident radiation at a plurality of pixels at corresponding locations, the radiographic projection comprising a plurality of radiation values corresponding to a plurality of pixel locations of the imaging device, each radiation value comprising a primary radiation amount representative of the radiation reaching the corresponding pixel along a direct path from the radiation source and a scattered radiation amount representative of other radiation reaching the corresponding pixel, the method comprising:

• obtaining an estimate of a radiation amount associated with a first location of the radiographic projection, the radiation amount comprising one of a radiation amount emitted by the radiation source or the primary radiation amount at the first location;
• generating an estimate of scattered radiation at a plurality of locations of the radiographic projection using the estimate of the radiation amount at the first location and a kernel that generates a value representative of scattered radiation for a location of the radiographic projection in relation to the distance between that location and the first location, the kernel having a form that is asymmetric about the location of the first pixel location, wherein the kernel comprises an amplitude factor and an asymmetric form factor that is a function of at least one a set of estimates of the object thickness and a set of estimates of the primary radiation in the radiographic projection, wherein the amplitude factor varies with location on the radiographic projection, wherein generating the estimate of scattered radiation further comprises finding at least one edge of the object in the radiographic projection and adjusting the values of the amplitude factor in areas around the at least one edge;
• and
• storing the estimate of the scattered radiation in a computer-readable medium.

A method of estimating scattered radiation in a radiographic projection of an object, the radiographic projection generated by an imaging device irradiated by a radiation source spaced therefrom to provide a space for the object, the imaging device measuring incident radiation at a plurality of pixels at corresponding locations, the radiographic projection comprising a plurality of radiation values corresponding to a plurality of pixel locations of the imaging device, each radiation value comprising a primary radiation amount representative of the radiation reaching the corresponding pixel along a direct path from the radiation source and a scattered radiation amount representative of other radiation reaching the corresponding pixel, the method comprising:

• obtaining a plurality of estimates of radiation amounts at a plurality of corresponding locations of the radiographic projection, each radiation amount comprising one of a radiation amount emitted by the radiation source or the primary radiation amount at the first location, wherein the radiographic projection comprises at least one area that was at least partially shaded from source radiation by a second object, the shading reducing the primary radiation amount in radiation values in the at least one area but not substantially reducing the scattered radiation amount in the radiation values;
• generating an estimate of scattered radiation at a plurality of locations of the radiographic projection using the obtained estimates of the radiation amount and a kernel that generates a value representative of scattered radiation for a location of the radiographic projection in relation to the distance between that location and the first location, the kernel having a form that is asymmetric about the location of the first pixel location;
• generating a reference estimate of at least one scattered radiation amount in the at least one partially shaded area;
• adjusting the estimate of scattered radiation using the reference estimate;
• and
• storing the estimate of the scattered radiation in a computer-readable medium.

A method of estimating scattered radiation in a radiographic projection of an object, the radiographic projection generated by an imaging device irradiated by a radiation source spaced therefrom to provide a space for the object, the imaging device measuring incident radiation at a plurality of pixels at corresponding locations, the radiographic projection comprising a plurality of radiation values corresponding to a plurality of pixel locations of the imaging device, each radiation value comprising a primary radiation amount representative of the radiation reaching the corresponding pixel along a direct path from the radiation source and a scattered radiation amount representative of other radiation reaching the corresponding pixel, the method comprising:

• correcting the radiation values of the radiographic projection for scattered radiation caused by a housing of an imaging device;
• obtaining an estimate of a radiation amount associated with a first location of the radiographic projection, the radiation amount comprising one of a radiation amount emitted by the radiation source or the primary radiation amount at the first location;
• generating an estimate of scattered radiation at a plurality of locations of the radiographic projection using the estimate of the radiation amount at the first location and a kernel that generates a value representative of scattered radiation for a location of the radiographic projection in relation to the distance between that location and the first location, the kernel having a form that is asymmetric about the location of the first pixel location;
• and
• storing the estimate of the scattered radiation in a computer-readable medium.

A method of estimating scattered radiation in a radiographic projection of an object, the radiographic projection generated by an imaging device irradiated by a radiation source spaced therefrom to provide a space for the object, the imaging device measuring incident radiation at a plurality of pixels at corresponding locations, the radiographic projection comprising a plurality of radiation values corresponding to a plurality of pixel locations of the imaging device, each radiation value comprising a primary radiation amount representative of the radiation reaching the corresponding pixel along a direct path from the radiation source and a scattered radiation amount representative of other radiation reaching the corresponding pixel, the method comprising:

• obtaining estimates of the primary radiation amounts at a plurality of corresponding locations of the radiographic projection;
• generating an estimate of scattered radiation at a plurality of locations of the radiographic projection based upon the estimates of the primary radiation amounts at the plurality of corresponding locations of the radiographic projection, an amplitude factor SA(*), and a symmetric form factor SFF(x,y), wherein generating the estimate of scattered radiation comprises:
• generating a first quantity representative of a convolution of the symmetric form factor SFF(x,y) and estimates of the primary radiation amounts scaled by the amplitude factor SA(*), multiplying the first quantity by a first function of the estimates of radiation amounts, and generating a second quantity representative of the symmetric form factor SFF(x,y) convolved with estimates of the primary radiation amounts that has been scaled by the amplitude factor SA(*) and multiplied by a second function of the estimates of the primary radiation amounts;
• and
• storing the estimate of the scattered radiation in a computer-readable medium.