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authorjaseg <git@jaseg.de>2021-06-02 00:02:36 +0200
committerjaseg <git@jaseg.de>2021-06-02 00:02:36 +0200
commit3b553b3a1dcbecb684e4d7eb00dac1c26874247b (patch)
treecbb21e706aadc8628f849d473370b4d78cb6eba6 /svg-flatten/src/nopencv.cpp
parent3386e586ac0f0ae07535036efe6293f6118f7e2b (diff)
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Chain approximation approximately working
Diffstat (limited to 'svg-flatten/src/nopencv.cpp')
-rw-r--r--svg-flatten/src/nopencv.cpp43
1 files changed, 32 insertions, 11 deletions
diff --git a/svg-flatten/src/nopencv.cpp b/svg-flatten/src/nopencv.cpp
index f42b6ad..afe4881 100644
--- a/svg-flatten/src/nopencv.cpp
+++ b/svg-flatten/src/nopencv.cpp
@@ -156,7 +156,7 @@ void gerbolyze::nopencv::find_blobs(gerbolyze::nopencv::Image32 &img, gerbolyze:
} else if (val_xy >= 1 && img.at_default(x+1, y) == 0) { /* hole border starting point */
nbd += 1;
- follow(img, x, y, D_E, nbd, 8, poly);
+ follow(img, x, y, D_E, nbd, 8, poly); /* FIXME should be 4? */
cb(poly, CP_HOLE);
poly.clear();
}
@@ -170,7 +170,8 @@ static size_t region_of_support(Polygon_i poly, size_t i) {
double last_l = 0;
double last_r = 0;
size_t k;
- for (k=0; k<sz/2; k++) {
+ //cerr << "d: ";
+ for (k=1; k<(sz+1)/2; k++) {
size_t idx1 = (i + k) % sz;
size_t idx2 = (i + sz - k) % sz;
double x1 = poly[idx1][0], y1 = poly[idx1][1], x2 = poly[idx2][0], y2 = poly[idx2][1];
@@ -179,17 +180,19 @@ static size_t region_of_support(Polygon_i poly, size_t i) {
* TODO: Check whether distance-to-line is an ok implementation here, the paper asks for distance to chord.
*/
double d = ((x2-x1)*(y1-y0) - (x1-x0)*(y2-y1)) / sqrt(pow(x2-x1, 2) + pow(y2-y1, 2));
+ //cerr << d << " ";
double r = d/l;
bool cond_a = l < last_l;
- bool cond_b = (d > 0) ? (r < last_r) : (r > last_r);
+ bool cond_b = ((d > 0) && (r < last_r)) || ((d < 0) && (r > last_r));
- if (cond_a || cond_b)
+ if (k > 2 && (cond_a || cond_b))
break;
last_l = l;
last_r = r;
}
+ //cerr << endl;
k -= 1;
return k;
}
@@ -228,7 +231,7 @@ double k_curvature(const Polygon_i &poly, size_t i, size_t k) {
for (size_t idx = 0; idx < k; idx++) {
acc += freeman_angle(poly, (i + 2*sz - idx) % sz) - freeman_angle(poly, (i+idx + 1) % sz);
}
- return acc / (2*k);
+ return acc / k;
}
double k_cos(const Polygon_i &poly, size_t i, size_t k) {
@@ -244,15 +247,17 @@ double k_cos(const Polygon_i &poly, size_t i, size_t k) {
return dp / (sqrt(sq_a)*sqrt(sq_b));
}
-ContourCallback gerbolyze::nopencv::simplify_contours_teh_chin(int kcos, ContourCallback cb) {
- return [&cb, kcos](Polygon_i &poly, ContourPolarity cpol) {
+ContourCallback gerbolyze::nopencv::simplify_contours_teh_chin(ContourCallback cb) {
+ return [&cb](Polygon_i &poly, ContourPolarity cpol) {
size_t sz = poly.size();
vector<size_t> ros(sz);
vector<double> sig(sz);
+ vector<double> cur(sz);
vector<bool> retain(sz);
for (size_t i=0; i<sz; i++) {
ros[i] = region_of_support(poly, i);
- sig[i] = fabs(k_cos(poly, i, kcos));
+ sig[i] = fabs(k_cos(poly, i, ros[i]));
+ cur[i] = k_curvature(poly, i, 1);
retain[i] = true;
}
@@ -281,9 +286,23 @@ ContourCallback gerbolyze::nopencv::simplify_contours_teh_chin(int kcos, Contour
}
cerr << endl;
+ /* Pass 0 (like opencv): Remove points with zero 1-curvature */
+ for (size_t i=0; i<sz; i++) {
+ if (cur[i] == 0) {
+ retain[i] = false;
+ break;
+ }
+ }
+
+ cerr << "pass 0: ";
+ for (size_t i=0; i<sz; i++) {
+ cerr << (retain[i] ? "#" : ".");
+ }
+ cerr << endl;
+
/* 3a, Pass 1: Non-maxima suppression */
for (size_t i=0; i<sz; i++) {
- for (size_t j=0; j<ros[i]/2; j++) {
+ for (size_t j=1; j<ros[i]/2; j++) {
if (sig[i] < sig[(i + j) % sz] || sig[i] < sig[(i + sz - j) % sz]) {
retain[i] = false;
break;
@@ -299,8 +318,10 @@ ContourCallback gerbolyze::nopencv::simplify_contours_teh_chin(int kcos, Contour
/* 3b, Pass 2: Zero-curvature suppression */
for (size_t i=0; i<sz; i++) {
- if (retain[i] && k_cos(poly, i, kcos) == 0) {
- retain[i] = false;
+ if (retain[i] && ros[i] == 1) {
+ if (sig[i] <= sig[(i + 1) % sz] || sig[i] <= sig[(i + sz - 1) % sz]) {
+ retain[i] = false;
+ }
}
}