CSE 690: GPGPU Lecture 8: Image Processing PDE Solvers

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CSE 690 GPGPULecture 8 Image Processing
PDE Solvers

• Klaus Mueller
• Computer Science, Stony Brook University

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A Quick Note

• The recent generations of GPUs do seem to conform
  to the IEEE floating point standard
• Nvidia site explicitely confirms this for Quadro
  FX
• R. Fernando, Eurographics 2004 (general new FX)
• Older generations do not (new generations?)
• see paper GPU Floating Paranoia by
  Hillesland/Lastra, GPGPU Workshop 2004
• IEEE sets clear conventions for rounding
• round to nearest representable number (basis 2)
• when tie, round to nearest even number

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Image Processing

• Simple mask operations
• smoothing, edge detection, averaging, median
• pixels under the mask are processed, combined,
  and written to output pixel

fragment program
input texture
output texture
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Image Processing

• Very streamable
• no data reuse
• fragments in -gt fragments out
• highly applicable to video processing
• GPU/CPU speedup results obtained by Payne et al.
  (GeForce FX 5900 vs. 2.8GHz P4)
• for 3x3 convolution masks and 1k x 1k images 30
• for 5x5 masks and 1k x 1k images 50-60 speedup
• for 2k x 2k images (double HDTV) get 15 fps,
  while CPU gets 1.8 fps

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Multigrid Solver

• Cliff Woolleys presentation at the Graphics
  Hardware Workshop 2003
• A Multigrid Solver for Boundary Value Problems
  Using Programmable Graphics Hardware
• paper by N. Goodnight, C. Woolley, G. Lewin, D.
  Luebke, and G. Humphries, U Virginia