Method and apparatus for calibrating three-dimensional camera in X-ray imaging, and storage medium

An apparatus for calibrating a three-dimensional (3D) camera in X-ray imaging, comprising:

• acquisition circuitry configured to a 3D image of a calibration plate that has been captured by a 3D camera,
• wherein the calibration plate comprises a positioning marker, and
• wherein the calibration plate is disposed a distance from an X-ray tube;
• and
• processing circuitry configured to:
• compute first 3D coordinates of the positioning marker in a 3D camera coordinate system based upon the 3D image;
• compute second 3D coordinates of the positioning marker in an X-ray tube coordinate system based upon the distance;
• compute, based upon the first 3D coordinates and the second 3D coordinates, a transformation matrix adapted to calibrate the 3D camera;
• and
• calibrate the 3D camera based upon the transformation matrix;
• compute a first radiation field range and a second radiation field range on the calibration plate corresponding to the first radiation field range;
• and
• compute a radiation field width calibration parameter yw and a radiation field height calibration parameter yh by evaluating:
• γ
• w
• =
• w
• c
• *
• SID
• H
• 1
• *
• w
• s
• ⁢
• and
• ⁢
• γ
• h
• =
• h
• c
• *
• SID
• H
• 1
• *
• h
• S
• ,
• wherein:
• H1 represents the distance,
• SID represents a source to image distance,
• ws represents a width in the first radiation field range,
• hs represents a height in the first radiation field range,
• wc represents a width in the second radiation field range, and
• hc represents a height in the second radiation field range.

A non-transitory computer-readable storage medium, having computer-readable instructions stored thereon that, when executed by processing circuitry, perform a calibration of a three-dimensional (3D) camera in X-ray imaging by:

• acquiring a 3D image of a calibration plate that has been captured by a 3D camera,
• wherein the calibration plate comprises a positioning marker, and
• wherein the calibration plate is disposed a distance from an X-ray tube;
• computing first 3D coordinates of the positioning marker in a 3D camera coordinate system based upon the 3D image;
• computing second 3D coordinates of the positioning marker in an X-ray tube coordinate system based upon the distance;
• computing, based upon the first 3D coordinates and the second 3D coordinates, a transformation matrix adapted to calibrate the 3D camera;
• and
• calibrating the 3D camera based upon the transformation matrix;
• compute a first radiation field range and a second radiation field range on the calibration plate corresponding to the first radiation field range;
• and
• compute a radiation field width calibration parameter yw and a radiation field height calibration parameter yh by evaluating:
• γ
• w
• =
• w
• c
• *
• SID
• H
• 1
• *
• w
• ε
• and
• γ
• h
• =
• h
• c
• *
• SID
• H
• 1
• *
• h
• s
• .
• wherein:
• H1 represents the distance,
• SID represents a source to image distance,
• ws represents a width in the first radiation field range,
• hs represents a height in the first radiation field range,
• wc represents a width in the second radiation field range, and
• hc represents a height in the second radiation field range.