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#include "CHelpers.h"
double* createCircleKernel(int rad, Vec<unsigned int>& kernelDims)
{
kernelDims.x = rad%2==0 ? rad+1 : rad;
kernelDims.y = rad%2==0 ? rad+1 : rad;
kernelDims.z = rad%2==0 ? rad+1 : rad;
double* kernel = new double[kernelDims.product()];
memset(kernel,0,sizeof(double)*kernelDims.product());
Vec<unsigned int> mid;
mid.x = kernelDims.x/2+1;
mid.y = kernelDims.y/2+1;
mid.z = kernelDims.z/2+1;
Vec<unsigned int> cur(0,0,0);
for (cur.x=0; cur.x < kernelDims.x ; ++cur.x)
{
for (cur.y=0; cur.y < kernelDims.y ; ++cur.y)
{
for (cur.z=0; cur.z < kernelDims.z ; ++cur.z)
{
if (cur.EuclideanDistanceTo(mid)<=rad)
kernel[kernelDims.linearAddressAt(cur)] = 1;
}
}
}
return kernel;
}
int calcOtsuThreshold(const double* normHistogram, int numBins)
{
//code modified from http://www.dandiggins.co.uk/arlib-9.html
double totalMean = 0.0f;
for (int i=0; i<numBins; ++i)
totalMean += i*normHistogram[i];
double class1Prob=0, class1Mean=0, temp1, curThresh;
double bestThresh = 0.0;
int bestIndex = 0;
for (int i=0; i<numBins; ++i)
{
class1Prob += normHistogram[i];
class1Mean += i * normHistogram[i];
temp1 = totalMean * class1Prob - class1Mean;
curThresh = (temp1*temp1) / (class1Prob*(1.0f-class1Prob));
if(curThresh>bestThresh)
{
bestThresh = curThresh;
bestIndex = i;
}
}
return bestIndex;
}