Acceleration of 3D, nonlinear warping using standard video graphics hardware: implementation and initial validation.
Thin Plate Spline (TPS) transformations are used in many medical imaging algorithms, but are time-prohibitive for iterative or interactive use. We have utilized current generation consumer 3D graphics cards to accelerate the application of the TPS nonlinear transformation by combining hardware accelerated 3D textures, vertex shaders and trilinear interpolation. Our hardware accelerated algorithm warped a 512x512x173 Computed Tomography (CT) dataset in 2.3 s, and the same study, scaled to 256x256x173, in 0.5 s, using a set of 92 landmarks. An accelerated software implementation of the TPS transformation warped the 512x512x173 study in 32.9 s and the 256x256x173 study in 9.5 s. Subtracted images were used for qualitative analysis of the warp and the Mutual Information (MI) and Sum of Absolute Difference (SAD) similarity metrics were used to quantitatively compare the output of the hardware accelerated algorithm to that of the software algorithm. The hardware accelerated algorithm provided a 7-65 times performance increase when compared to the software algorithm, and produced output of comparable quality (MI > 300 and SAD < 1.75%).
Levin
David
D
Department of Medical Biophysics, University of Western Ontario, London, Ont., Canada.
Dey
Damini
D
Slomka
Piotr J
PJ
D000465:Algorithms; D016477:Artifacts; D003196:Computer Graphics; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D014057:Tomography, X-Ray Computed