Meaning
Mathematical algorithm used to generate three-dimensional volumes from two-dimensional X-ray projections captured by a cone-beam scanner. The feldkamp-davis-kress reconstruction provides a computationally efficient way to process data by weighting and filtering projections before back-projecting them into a grid. It represents the standard approach for circular trajectory scans in industrial metrology.
Image Synthesis
Synthesis of the volume occurs through a filtered back-projection technique that accounts for the divergent geometry of the X-ray cone. This method ensures that the voxels at the top and bottom of the scan are as accurate as those in the center.
Geometric Accuracy
Accuracy of the reconstruction depends on the precise alignment of the source, the object and the detector. If the axis of rotation is slightly off, the resulting image will show blurring or double edges. Regular calibration of the scanning hardware is required to maintain the integrity of the measurements.
Artifact Reduction
Reduction of cone-beam artifacts is the primary challenge for this algorithm when scanning flat or long objects. The reconstruction uses weighting functions to minimize the distortion caused by the steep angle of the X-rays at the edges of the detector. High-performance computing allows these calculations to finish in minutes rather than hours.
