Fig 1.
The principle of HDR-CT imaging.
For the complicated components, get multi-voltage sequences at one projection angle, which are responding to different thickness. Then by HDR fusion and CT reconstruction, get the full information.
Fig 2.
The thickness is the notable difference. The bottom is solid, the center is hollowed-out, and the top is irregular.
Fig 3.
The image sequences collected at varying energies.
Each row corresponds to a different projection angle (0° and 90°), and each column corresponds to a different transillumination voltage (60 kV, 70 kV, 80 kV, 90 kV, and 100 kV).
Fig 4.
This system is composed by X-ray (GE ISOVOLT 450KV) and detector (VARIAN PaxScan2520).
Fig 5.
Single-voltage CT images with different energy and different part.
Every column is the 60kV, 80kV and 100kV at the same prat. Every row is the bottom, center, and top part at the same voltage.
Fig 6.
The corresponding gray figure between 90kV and 100 kV at 0°.
Horizontal axis represents the gray of one tube-voltage image, and vertical axis represents the next tube-voltage. These points represent the gray of one point about object in the adjacent two frames images.
Fig 7.
The processed gray figure about 90kV and 100kV.
That has excluded the non-interesting area (overexposed area and “strip-like” noise).
Fig 8.
The fused HDR projections at 0°, 90°, 180°, and 270°.
Fig 9.
HDR-CT reconstruction results.
The first row CT image from left to right is corresponding to bottom, center and top about workpiece, The second row is respectively the gray curve at the indicated line. In these CT image the construction is full, but the image quality is poor, and noise level is higher.
Fig 10.
CT images obtained using the improved fused images.
The first row CT image from left to right is corresponding to bottom, center and top about workpiece, The second row is respectively the gray curve at the indicated line. Relative to Fig 8, image quality and noise have major improvement
Fig 11.
3D visualizations of the real workpiece at various viewing angles.
Fig 12.
3D sections viewed from various axes.