BoxBlur2DKernel

The BoxBlur2DKernel does a two-dimensional box blur on its input. The horizontal radius, RadiusX, and vertical radius, RadiusY can be separately controlled.

kernel BoxBlur2D : public ImageComputationKernel<eComponentWise>
{
  Image<eRead, eAccessRanged2D, eEdgeClamped> src;
  Image<eWrite, eAccessPoint> dst;

param:
  int xRadius;  //The horizontal radius of our box blur
  int yRadius;  //The vertical radius of our box blur

local:
  int _filterSize;

  void define() {
    defineParam(xRadius, "RadiusX", 5, eParamProxyScale);
    defineParam(yRadius, "RadiusY", 3, eParamProxyScale);
  }

  void init() {
    //Set the range we need to access from the source 
    src.setRange(-xRadius, -yRadius, xRadius, yRadius);

    _filterSize = (2 * xRadius + 1) * (2 * yRadius + 1);
  }

  void process() {
    float sum = 0.0f;
    for(int j = -yRadius; j <= yRadius; j++)
      for(int i = -xRadius; i <= xRadius; i++)
        sum += src(i, j);
    dst() = sum / (float)_filterSize;
  }
};