void FourierDescriptorsExtractor::_getBoundaryPolygon( const Image &_img,
std::vector<Vec2d> &poly )
{
IntDeque cont;
_getContour(_img, cont);
for (int i = cont.size() - 1; i >= 0; i--)
{
int &p = cont[i];
Vec2d v;
v.y = p / (_img.getWidth() + 1);
v.x = p % (_img.getWidth() + 1);
poly.push_back(v);
}
//return;
poly.push_back(Vec2d(poly[0])); //Vec2d(poly[0])
_approximatePolygon(poly);
//Array<Vec2d> approximated;
//Approximator::apply(poly, approximated);
//poly.copy(approximated);
//_drawPolygon(_img, poly);
}
bool Init()
{
int nRandom = 0;
for (int i = 0; i < g_nMax; ++i)
{
nRandom = i;
g_nSummary += nRandom;
g_dInts.push_back(nRandom);
g_hmInts.insert(std::make_pair(nRandom, nRandom));
g_hsInts.insert(nRandom);
g_lInts.push_back(nRandom);
g_mInts.insert(std::make_pair(nRandom, nRandom));
g_mmInts.insert(std::make_pair(nRandom, nRandom));
g_msInts.insert(nRandom);
g_sInts.insert(nRandom);
g_vInts.push_back(nRandom);
}
return true;
}
void FourierDescriptorsExtractor::_getContour( const Image &_img, IntDeque &cont )
{
Image img;
img.copy(_img);
Binarizer(img, 190).apply();
//ImageUtils::saveImageToFile(img, "output/gc.png");
int w = img.getWidth(), h = img.getHeight();
int k = (h + 1) * (w + 1);
int begin = 0, x, y;
byte ul, ur, dl, dr;
int i;
std::deque<int> prev(k, -1);
double dist = 0;
double min_dist = 1e16;
for (i = 0; i < w * h; i++)
{
if (img[i] != 255)
{
y = i / w;
x = i % w;
//begin = y * (w + 1) + x;
dist = sqrt((double)x * x + y * y);
if (min_dist - dist > EPS)
{
min_dist = dist;
begin = i + i / w;
}
//begin = i + i / w;
//break;
}
}
std::stack<int> stack;
int cur, p = 0;
int t = 0, s = 0;
int next[4] = {-1, -1, -1, -1};
int delta;
int first;
first = begin + 1;
y = first / (w + 1);
x = first % (w + 1);
if (begin >= w + 2 && img[first - 1 - y] != 255 &&
img[first - w - 1 - (y - 1)] != 255 &&
img[first - y] != 0 && img[first - w - 1 - 1 - (y - 1)] != 0)
{
first -= w + 1;
}
cur = first;
stack.push(cur);
int iterations = 0;
while (true)
{
iterations++;
if (iterations > k)
throw NoContourException("infinite loop");
if (stack.size() == 0)
throw NoContourException();
cur = stack.top();
stack.pop();
prev[cur] = p;
delta = cur - p;
if (cur == begin)
break;
y = cur / (w + 1);
x = cur % (w + 1);
if (y > 0 && y < h && x > 0 && x < w)
{
if (img[cur - y] != 255 && img[cur - w - 1 - 1 - (y - 1)] != 255 &&
img[cur - 1 - y] != 0 && img[cur - w - 1 - (y - 1)] != 0)
{
if (delta == w + 1 || delta == w)
t = cur + 1;
else if (delta == -1) // || delta == w + 2
t = cur - w - 1;
else if (delta == -(w + 1) || delta == -w)
t = cur - 1;
else if (delta == 1) // || delta == -(w + 2)
t = cur + w + 1;
prev[cur] = -1;
stack.push(t);
continue;
}
if (img[cur - 1 - y] != 255 && img[cur - w - 1 - (y - 1)] != 255 &&
img[cur - y] != 0 && img[cur - w - 1 - 1 - (y - 1)] != 0)
{
if (delta == w + 1) // || delta == w
t = cur - 1;
else if (delta == -1 || delta == -(w + 2))
t = cur + w + 1;
else if (delta == -(w + 1)) // || delta == -w
t = cur + 1;
else if (delta == 1 || delta == w + 2)
t = cur - (w + 1);
prev[cur] = -1;
stack.push(t);
continue;
}
}
if (delta == 1 || delta == (w + 2))
s = 4;
else if (delta == (w + 1) || delta == w || delta == 2 * (w + 1))
s = 3;
else if (delta == -1 || delta == -(w + 2))
s = 2;
else if (delta == -(w + 1) || delta == -w || delta == -2 * (w + 1))
s = 1;
//Where can we go from there
ul = (x - 1 >= 0 && y - 1 >= 0)?img.getByte(x - 1, y - 1):255;
ur = (x < w && y - 1 >= 0)?img.getByte(x, y - 1):255;
dl = (x - 1 >= 0 && y < h)?img.getByte(x - 1, y):255;
dr = (x < w && y < h)?img.getByte(x, y):255;
if (y - 1 >= 0 && (ul - ur) != 0)
{
next[(s + 0) % 4] = cur - w - 1;
}
if (x + 1 < w + 1 && (ur - dr) != 0)
{
next[(s + 1) % 4] = cur + 1;
}
if (y + 1 < h + 1 && (dr - dl) != 0)
{
next[(s + 2) % 4] = cur + w + 1;
}
if (x - 1 >= 0 && (dl - ul) != 0)
{
next[(s + 3) % 4] = cur - 1;
}
for (i = 3; i >= 0; i--)
{
if (next[i] != -1)
{
if (prev[next[i]] == -1)
stack.push(next[i]);
next[i] = -1;
}
}
p = cur;
}
cont.clear();
cur = prev[begin];
do
{
cont.push_back(cur);
cur = prev[cur];
} while (cur != first);
cont.push_back(begin);
}
IntList::iterator
copyList (IntList::iterator c, IntDeque &lst) {
return std::copy (lst.begin (), lst.end (), c);
}
