Fastest CPU (AVX/SSE) implementation of RGB to grayscale. Roughly 3x faster than OpenCV's implementation with AVX2, or 2x faster than OpenCV's implementation if using SSE only.

Converts an RGB color image to grayscale.

You can use equal weighting by calling the templated function with weight set to 'false', or you can specify non-equal weights (only slightly slower).

The default non-equal weights match OpenCV's default.

For even more speed see the CUDA version: github.com/komrad36/CUDARGB2Y

If you do not have AVX2, uncomment the #define NO_AVX_PLEASE below to use only SSE isntructions. NOTE THAT THIS IS ABOUT 50% SLOWER. A processor with full AVX2 support is highly recommended.

All functionality is contained in RGB2Y.h. 'main.cpp' is a demo and test harness.