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-rw-r--r--svg-flatten/src/nopencv.cpp84
-rw-r--r--svg-flatten/src/nopencv.hpp3
-rw-r--r--svg-flatten/src/test/nopencv_test.cpp8
-rw-r--r--svg-flatten/src/test/svg_tests.py3
-rw-r--r--svg-flatten/src/vec_core.cpp6
5 files changed, 91 insertions, 13 deletions
diff --git a/svg-flatten/src/nopencv.cpp b/svg-flatten/src/nopencv.cpp
index 0643b20..121e9e1 100644
--- a/svg-flatten/src/nopencv.cpp
+++ b/svg-flatten/src/nopencv.cpp
@@ -1,6 +1,7 @@
#include <iostream>
#include <iomanip>
+#include <stack>
#include "nopencv.hpp"
@@ -399,6 +400,79 @@ ContourCallback gerbolyze::nopencv::simplify_contours_teh_chin(ContourCallback c
};
}
+static double dp_eps(double dx, double dy) {
+ /* Implementation of:
+ *
+ * Prasad, Dilip K., et al. "A novel framework for making dominant point detection methods non-parametric."
+ * Image and Vision Computing 30.11 (2012): 843-859.
+ * https://core.ac.uk/download/pdf/131287229.pdf
+ *
+ * For another implementation, see:
+ * https://github.com/BobLd/RamerDouglasPeuckerNetV2/blob/master/RamerDouglasPeuckerNetV2.Test/RamerDouglasPeuckerNetV2/RamerDouglasPeucker.cs
+ */
+ double m = dy / dx;
+ double s = sqrt(pow(dx, 2) + pow(dy, 2));
+ double phi = atan(m);
+ double t_max = 1/s * (fabs(cos(phi)) + fabs(sin(phi)));
+ double t_max_polynomial = 1 - t_max + pow(t_max, 2);
+ return s * fmax(
+ atan(1/s * fabs(sin(phi) + cos(phi)) * t_max_polynomial),
+ atan(1/s * fabs(sin(phi) - cos(phi)) * t_max_polynomial));
+}
+
+/* a, b inclusive */
+static array<size_t, 3> dp_step(Polygon_i &poly, size_t a, size_t b) {
+
+ double dx = poly[b][0] - poly[a][0];
+ double dy = poly[b][1] - poly[a][1];
+ double eps = dp_eps(dx, dy);
+
+ size_t max_idx = 0;
+ double max_dist = 0;
+ /* https://en.wikipedia.org/wiki/Distance_from_a_point_to_a_line */
+ double dist_ab = sqrt(pow(poly[b][0] - poly[a][0], 2) + pow(poly[b][1] - poly[a][1], 2));
+ for (size_t i=a+1; i<b; i++) {
+ double dist_i = fabs(
+ (poly[b][0] - poly[a][0]) * (poly[a][1] - poly[i][1])
+ - (poly[a][0] - poly[i][0]) * (poly[b][1] - poly[a][1]))
+ / dist_ab;
+ if (dist_i > max_dist && dist_i > eps) {
+ max_dist = dist_i;
+ max_idx = i;
+ }
+ }
+
+ return {a, max_idx, b};
+}
+
+ContourCallback gerbolyze::nopencv::simplify_contours_douglas_peucker(ContourCallback cb) {
+ return [&cb](Polygon_i &poly, ContourPolarity cpol) {
+
+ Polygon_i out;
+ out.push_back(poly[0]);
+
+ stack<array<size_t, 3>> indices;
+ indices.push(dp_step(poly, 0, poly.size()-1));
+
+ while (!indices.empty()) {
+ auto idx = indices.top();
+ indices.pop(); /* awesome C++ api let's goooooo */
+
+ if (idx[1] > 0) {
+ indices.push(dp_step(poly, idx[0], idx[1]));
+
+ indices.push(dp_step(poly, idx[1], idx[2]));
+
+ } else {
+ out.push_back(poly[idx[2]]);
+ }
+ }
+
+
+ cb(out, cpol);
+ };
+}
+
double gerbolyze::nopencv::polygon_area(Polygon_i &poly) {
double acc = 0;
size_t prev = poly.size() - 1;
@@ -432,13 +506,13 @@ bool gerbolyze::nopencv::Image<T>::load_memory(const void *buf, size_t len) {
}
template<typename T>
-void gerbolyze::nopencv::Image<T>::binarize() {
+void gerbolyze::nopencv::Image<T>::binarize(T threshold) {
assert(m_data != nullptr);
assert(m_rows > 0 && m_cols > 0);
for (int y=0; y<m_rows; y++) {
for (int x=0; x<m_cols; x++) {
- m_data[y*m_cols + x] = m_data[y*m_cols + x] > 0;
+ m_data[y*m_cols + x] = m_data[y*m_cols + x] >= threshold;
}
}
}
@@ -494,20 +568,20 @@ void gerbolyze::nopencv::Image<uint8_t>::resize(int new_w, int new_h) {
template gerbolyze::nopencv::Image<int32_t>::Image(int size_x, int size_y, const int32_t *data);
template bool gerbolyze::nopencv::Image<int32_t>::load(const char *filename);
template bool gerbolyze::nopencv::Image<int32_t>::load_memory(const void *buf, size_t len);
-template void gerbolyze::nopencv::Image<int32_t>::binarize();
+template void gerbolyze::nopencv::Image<int32_t>::binarize(int32_t threshold);
template bool gerbolyze::nopencv::Image<int32_t>::stb_to_internal(uint8_t *data);
template void gerbolyze::nopencv::Image<int32_t>::blur(int radius);
template gerbolyze::nopencv::Image<uint8_t>::Image(int size_x, int size_y, const uint8_t *data);
template bool gerbolyze::nopencv::Image<uint8_t>::load(const char *filename);
template bool gerbolyze::nopencv::Image<uint8_t>::load_memory(const void *buf, size_t len);
-template void gerbolyze::nopencv::Image<uint8_t>::binarize();
+template void gerbolyze::nopencv::Image<uint8_t>::binarize(uint8_t threshold);
template bool gerbolyze::nopencv::Image<uint8_t>::stb_to_internal(uint8_t *data);
template void gerbolyze::nopencv::Image<uint8_t>::blur(int radius);
template gerbolyze::nopencv::Image<float>::Image(int size_x, int size_y, const float *data);
template bool gerbolyze::nopencv::Image<float>::load(const char *filename);
template bool gerbolyze::nopencv::Image<float>::load_memory(const void *buf, size_t len);
-template void gerbolyze::nopencv::Image<float>::binarize();
+template void gerbolyze::nopencv::Image<float>::binarize(float threshold);
template bool gerbolyze::nopencv::Image<float>::stb_to_internal(uint8_t *data);
template void gerbolyze::nopencv::Image<float>::blur(int radius);
diff --git a/svg-flatten/src/nopencv.hpp b/svg-flatten/src/nopencv.hpp
index 8f399b9..5dd399d 100644
--- a/svg-flatten/src/nopencv.hpp
+++ b/svg-flatten/src/nopencv.hpp
@@ -60,7 +60,7 @@ namespace gerbolyze {
bool load(const char *filename);
bool load_memory(const void *buf, size_t len);
- void binarize();
+ void binarize(T threshold);
T &at(int x, int y) {
assert(x >= 0 && y >= 0 && x < m_cols && y < m_rows);
@@ -116,6 +116,7 @@ namespace gerbolyze {
void find_contours(Image32 &img, ContourCallback cb);
ContourCallback simplify_contours_teh_chin(ContourCallback cb);
+ ContourCallback simplify_contours_douglas_peucker(ContourCallback cb);
double polygon_area(Polygon_i &poly);
}
diff --git a/svg-flatten/src/test/nopencv_test.cpp b/svg-flatten/src/test/nopencv_test.cpp
index b32d22c..e4cc078 100644
--- a/svg-flatten/src/test/nopencv_test.cpp
+++ b/svg-flatten/src/test/nopencv_test.cpp
@@ -181,7 +181,7 @@ int render_svg(const char *in_svg, const char *out_png) {
static void testdata_roundtrip(const char *fn) {
Image32 ref_img;
mu_assert(ref_img.load(fn), "Input image failed to load");
- ref_img.binarize();
+ ref_img.binarize(128);
Image32 ref_img_copy(ref_img);
TempfileHack tmp_svg(".svg");
@@ -195,7 +195,7 @@ static void testdata_roundtrip(const char *fn) {
Image32 out_img;
mu_assert(out_img.load(tmp_png.c_str()), "Output image failed to load");
- out_img.binarize();
+ out_img.binarize(128);
mu_assert_int_eq(ref_img.cols(), out_img.cols());
mu_assert_int_eq(ref_img.rows(), out_img.rows());
@@ -231,7 +231,7 @@ static void test_polygon_area(const char *fn) {
//cerr << endl << "poly area test " << fn << endl;
Image32 ref_img;
mu_assert(ref_img.load(fn), "Input image failed to load");
- ref_img.binarize();
+ ref_img.binarize(128);
int white_px_count = 0;
int black_px_count = 0;
@@ -283,7 +283,7 @@ static void chain_approx_test(const char *fn) {
//cout << endl << "Testing \"" << fn << "\"" << endl;
Image32 ref_img;
mu_assert(ref_img.load(fn), "Input image failed to load");
- ref_img.binarize();
+ ref_img.binarize(128);
Image32 ref_img_copy(ref_img);
TempfileHack tmp_svg(".svg");
diff --git a/svg-flatten/src/test/svg_tests.py b/svg-flatten/src/test/svg_tests.py
index 7f1adb0..e4cff76 100644
--- a/svg-flatten/src/test/svg_tests.py
+++ b/svg-flatten/src/test/svg_tests.py
@@ -100,8 +100,9 @@ class SVGRoundTripTests(unittest.TestCase):
#print_stats(ref)
#print_stats(out)
- #print(f'{test_name}: mean={delta.mean():.5g}')
+ print(f'{test_name}: mean={delta.mean():.5g}')
+ self.fail('debug')
self.assertTrue(delta.mean() < mean,
f'Expected mean pixel difference between images to be <{mean}, was {delta.mean():.5g}')
diff --git a/svg-flatten/src/vec_core.cpp b/svg-flatten/src/vec_core.cpp
index 2819965..86641dd 100644
--- a/svg-flatten/src/vec_core.cpp
+++ b/svg-flatten/src/vec_core.cpp
@@ -435,8 +435,10 @@ void gerbolyze::OpenCVContoursVectorizer::vectorize_image(xform2d &mat, const pu
draw_bg_rect(local_xf, width, height, clip_path, sink);
- img->binarize();
- nopencv::find_contours(*img, nopencv::simplify_contours_teh_chin([&sink, &local_xf, &clip_path, off_x, off_y, scale_x, scale_y](Polygon_i& poly, nopencv::ContourPolarity pol) {
+ img->binarize(128);
+ nopencv::find_contours(*img,
+ nopencv::simplify_contours_douglas_peucker(
+ [&sink, &local_xf, &clip_path, off_x, off_y, scale_x, scale_y](Polygon_i& poly, nopencv::ContourPolarity pol) {
if (pol == nopencv::CP_HOLE) {
std::reverse(poly.begin(), poly.end());
generated by cgit (git 2.34.1) at 2024-11-10 13:37:26 +0000