#include "CHelpers.h" double* createEllipsoidKernel(Vec<size_t> radii, Vec<size_t>& kernelDims) { kernelDims.x = radii.x*2+1; kernelDims.y = radii.y*2+1; kernelDims.z = radii.z*2+1; double* kernel = new double[kernelDims.product()]; memset(kernel,0,sizeof(double)*kernelDims.product()); Vec<size_t> mid; mid.x = (kernelDims.x+1)/2; mid.y = (kernelDims.y+1)/2; mid.z = (kernelDims.z+1)/2; Vec<float> dimScale(1.0f/((float)SQR(radii.x)),1.0f/((float)SQR(radii.y)),1.0f/((float)SQR(radii.z))); Vec<size_t> cur(0,0,0); for (cur.z=0; cur.z<kernelDims.z ; ++cur.z) { for (cur.y=0; cur.y<kernelDims.y ; ++cur.y) { for (cur.x=0; cur.x<kernelDims.x ; ++cur.x) { if (dimScale.x*SQR(cur.x-mid.x)+dimScale.y*SQR(cur.y-mid.y)+dimScale.z*SQR(cur.z-mid.z)<=1) kernel[kernelDims.linearAddressAt(cur)] = 1.0f; } } } 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; }