ocl-examples

This repository includes several examples using OpenCL.

Build

cmake is used to generate either Makefiles or projects for Visual Studio.

Out-of-source build is recommended, e.g.

mkdir ocl-examples-build
cd ocl-examples-build
cmake ocl-examples/CMakeLists.txt

For fft and blas, clFFT and clBLAS have to be available for linking. If the libraries are not installed system-wide, they have to be placed in the dist-directory.
The file dist/tree shows the directory structure expected.

Example Image Format

Some examples contain .dat images. These are essentially pgm images with stripped headers, containing only raw pixels, one byte per pixel, in the range of 0...ff to simplify reading images.

Results are generated using Bitmap file format.

Examples

• transpose:
  Simple Matrix transposition using only global memory.

• matrix:
  Different implementations of matrix-matrix multiplication. The examples are inspired by http://www.cs.bris.ac.uk/home/simonm/workshops/OpenCL_lecture3.pdf.

• sync:
  Reduction in shared memory to demonstrate barrier functions to synchronize work items inside a work group.

• reduce:
  Parallel reduction, inspired by http://developer.amd.com/resources/documentation-articles/articles-whitepapers/opencl-optimization-case-study-simple-reductions/.

• gauss:
  Demonstrate data transfer between OpenCL images and normal buffers using a gauss filter to smooth a distorded image.

• interpolation:
  Enlarge/reduce the size of an image using OpenCL images.

• blas:
  Matrix-Matrix multiplication using clBLAS.

• fft:
  Remove a regular distortion pattern from an image using forward- and backward FFT-transformation with the external library clFFT.