Industrial CT Reconstruction Algorithm Acceleration And 3D Visualization Technology

In industrial CT reconstruction, large amounts of reconstruction data and high computation complexity always lead to problems such as long reconstruction time, expensive reconstruction hardware platform, hardly meeting the engineering needs. Thus, the acceleration of CT reconstruction algorithm on ordinary PC has been a hotspot for several years. In addition, we have to face to the high cost brought by using commercial software in3 D visualization for CT. To solve these problems, this paper mainly studies the implementation of accelerating algorithm and the design of 3D visualization software for CT reconstruction. The main contributions are outlined as follows:1. Each step of FDK reconstruction algorithm is accelerated by using CUDA. Such operations can obtain 70 times speed-up ratio comparing with CPU. In the process of weighting and filtering, data transmission time in the host and device is reduced to increase bandwidth utilization ratio and shorten data transmission delay. Also, reconstruction data is rearranged to decrease the storage space and invalid operations in filtering. In addition,texture hardware interpolation is utilized in projection reconstruction to improve the computation speed instead of software interpolation. Further more, the result of trigonometric function is bound to the constant storage early to reduce the time to access the memory.2. An improved method for 2D projection coefficient calculation is put forward, which uses double arrays to correct projection coefficient in ART reconstruction algorithm.Experiments show that this algorithm can achieve almost 11 times speed-up radio comparing with Siddon algorithm, and 1.6 times faster than the algorithm mentioned in literature [45].Comparing with Siddon algorithm, the speed-up ratio can reach more than 30 when using CUDA to accelerate. The improved method can also extend to SART, ML-EM, OS-EM andOS-SART and it obtains close to 2 times speed-up radio comparing with the algorithm mentioned in literature [45].3. A 3D visualization software based on VTK is designed and developed combining with MFC. This software is divided into four display window to show the overall and each section.The slices in both 2D raw format and DICOM format can be read and showed. The software also supports for rotation, scaling, translation of 3D data and can realize the arbitrary cutting from any angle.