void ImageUtility3::ComputeCDConvex(Image3<int>& image)
{
int const dim0 = image.GetDimension(0);
int const dim1 = image.GetDimension(1);
int const dim2 = image.GetDimension(2);
Image3<int> temp = image;
int i0, i1, i2;
for (i1 = 0; i1 < dim1; ++i1)
{
for (i0 = 0; i0 < dim0; ++i0)
{
int i2min;
for (i2min = 0; i2min < dim2; ++i2min)
{
if ((temp(i0, i1, i2min) & 1) == 0)
{
temp(i0, i1, i2min) |= 2;
}
else
{
break;
}
}
if (i2min < dim2)
{
int i2max;
for (i2max = dim2 - 1; i2max >= i2min; --i2max)
{
if ((temp(i0, i1, i2max) & 1) == 0)
{
temp(i0, i1, i2max) |= 2;
}
else
{
break;
}
}
}
}
}
for (i2 = 0; i2 < dim2; ++i2)
{
for (i0 = 0; i0 < dim0; ++i0)
{
int i1min;
for (i1min = 0; i1min < dim1; ++i1min)
{
if ((temp(i0, i1min, i2) & 1) == 0)
{
temp(i0, i1min, i2) |= 2;
}
else
{
break;
}
}
if (i1min < dim1)
{
int i1max;
for (i1max = dim1 - 1; i1max >= i1min; --i1max)
{
if ((temp(i0, i1max, i2) & 1) == 0)
{
temp(i0, i1max, i2) |= 2;
}
else
{
break;
}
}
}
}
}
for (i2 = 0; i2 < dim2; ++i2)
{
for (i1 = 0; i1 < dim1; ++i1)
{
int i0min;
for (i0min = 0; i0min < dim0; ++i0min)
{
if ((temp(i0min, i1, i2) & 1) == 0)
{
temp(i0min, i1, i2) |= 2;
}
else
{
break;
}
}
if (i0min < dim0)
{
int i0max;
for (i0max = dim0 - 1; i0max >= i0min; --i0max)
{
if ((temp(i0max, i1, i2) & 1) == 0)
{
temp(i0max, i1, i2) |= 2;
}
else
{
break;
}
}
}
}
}
for (size_t i = 0; i < image.GetNumPixels(); ++i)
{
image[i] = (temp[i] & 2 ? 0 : 1);
}
}
void ImageUtility3::GetComponents(int numNeighbors, int const* delta,
Image3<int>& image, std::vector<std::vector<size_t>>& components)
{
size_t const numVoxels = image.GetNumPixels();
int* numElements = new int[numVoxels];
size_t* vstack = new size_t[numVoxels];
size_t i, numComponents = 0;
int label = 2;
for (i = 0; i < numVoxels; ++i)
{
if (image[i] == 1)
{
int top = -1;
vstack[++top] = i;
int& count = numElements[numComponents + 1];
count = 0;
while (top >= 0)
{
size_t v = vstack[top];
image[v] = -1;
int j;
for (j = 0; j < numNeighbors; ++j)
{
size_t adj = v + delta[j];
if (image[adj] == 1)
{
vstack[++top] = adj;
break;
}
}
if (j == numNeighbors)
{
image[v] = label;
++count;
--top;
}
}
++numComponents;
++label;
}
}
delete[] vstack;
if (numComponents > 0)
{
components.resize(numComponents + 1);
for (i = 1; i <= numComponents; ++i)
{
components[i].resize(numElements[i]);
numElements[i] = 0;
}
for (i = 0; i < numVoxels; ++i)
{
int value = image[i];
if (value != 0)
{
// Labels started at 2 to support the depth-first search,
// so they need to be decremented for the correct labels.
image[i] = --value;
components[value][numElements[value]] = i;
++numElements[value];
}
}
}
delete[] numElements;
}
