Finish chain approximation tests

2 files changed, 186 insertions, 102 deletions

diff --git a/svg-flatten/src/nopencv.cpp b/svg-flatten/src/nopencv.cpp
index afe4881..2384fcc 100644
--- a/svg-flatten/src/nopencv.cpp
+++ b/svg-flatten/src/nopencv.cpp
@@ -247,6 +247,7 @@ double k_cos(const Polygon_i &poly, size_t i, size_t k) {
     return dp / (sqrt(sq_a)*sqrt(sq_b));
 }
 
+constexpr bool debug = false;
 ContourCallback gerbolyze::nopencv::simplify_contours_teh_chin(ContourCallback cb) {
     return [&cb](Polygon_i &poly, ContourPolarity cpol) {
         size_t sz = poly.size();
@@ -261,30 +262,32 @@ ContourCallback gerbolyze::nopencv::simplify_contours_teh_chin(ContourCallback c
             retain[i] = true;
         }
 
-        cerr << endl;
-        cerr << "Polarity: " << cpol <<endl;
-        cerr << "Coords:"<<endl;
-        cerr << "  x: ";
-        for (size_t i=0; i<sz; i++) {
-            cerr << setfill(' ') << setw(2) << poly[i][0] << " ";
-        }
-        cerr << endl;
-        cerr << "  y: ";
-        for (size_t i=0; i<sz; i++) {
-            cerr << setfill(' ') << setw(2) << poly[i][1] << " ";
-        }
-        cerr << endl;
-        cerr << "Metrics:"<<endl;
-        cerr << "ros: ";
-        for (size_t i=0; i<sz; i++) {
-            cerr << setfill(' ') << setw(2) << ros[i] << " ";
-        }
-        cerr << endl;
-        cerr << "sig: ";
-        for (size_t i=0; i<sz; i++) {
-            cerr << setfill(' ') << setw(2) << sig[i] << " ";
+        if (debug) {
+            cerr << endl;
+            cerr << "Polarity: " << cpol <<endl;
+            cerr << "Coords:"<<endl;
+            cerr << "  x: ";
+            for (size_t i=0; i<sz; i++) {
+                cerr << setfill(' ') << setw(2) << poly[i][0] << " ";
+            }
+            cerr << endl;
+            cerr << "  y: ";
+            for (size_t i=0; i<sz; i++) {
+                cerr << setfill(' ') << setw(2) << poly[i][1] << " ";
+            }
+            cerr << endl;
+            cerr << "Metrics:"<<endl;
+            cerr << "ros: ";
+            for (size_t i=0; i<sz; i++) {
+                cerr << setfill(' ') << setw(2) << ros[i] << " ";
+            }
+            cerr << endl;
+            cerr << "sig: ";
+            for (size_t i=0; i<sz; i++) {
+                cerr << setfill(' ') << setw(2) << sig[i] << " ";
+            }
+            cerr << endl;
         }
-        cerr << endl;
 
         /* Pass 0 (like opencv): Remove points with zero 1-curvature */
         for (size_t i=0; i<sz; i++) {
@@ -294,11 +297,13 @@ ContourCallback gerbolyze::nopencv::simplify_contours_teh_chin(ContourCallback c
             }
         }
 
-        cerr << "pass 0: ";
-        for (size_t i=0; i<sz; i++) {
-            cerr << (retain[i] ? "#" : ".");
+        if (debug) {
+            cerr << "pass 0: ";
+            for (size_t i=0; i<sz; i++) {
+                cerr << (retain[i] ? "#" : ".");
+            }
+            cerr << endl;
         }
-        cerr << endl;
 
         /* 3a, Pass 1: Non-maxima suppression */
         for (size_t i=0; i<sz; i++) {
@@ -310,11 +315,13 @@ ContourCallback gerbolyze::nopencv::simplify_contours_teh_chin(ContourCallback c
             }
         }
 
-        cerr << "pass 1: ";
-        for (size_t i=0; i<sz; i++) {
-            cerr << (retain[i] ? "#" : ".");
+        if (debug) {
+            cerr << "pass 1: ";
+            for (size_t i=0; i<sz; i++) {
+                cerr << (retain[i] ? "#" : ".");
+            }
+            cerr << endl;
         }
-        cerr << endl;
         
         /* 3b, Pass 2: Zero-curvature suppression */
         for (size_t i=0; i<sz; i++) {
@@ -325,11 +332,13 @@ ContourCallback gerbolyze::nopencv::simplify_contours_teh_chin(ContourCallback c
             }
         }
 
-        cerr << "pass 2: ";
-        for (size_t i=0; i<sz; i++) {
-            cerr << (retain[i] ? "#" : ".");
+        if (debug) {
+            cerr << "pass 2: ";
+            for (size_t i=0; i<sz; i++) {
+                cerr << (retain[i] ? "#" : ".");
+            }
+            cerr << endl;
         }
-        cerr << endl;
 
         /* 3c, Pass 3: Further thinning */
         for (size_t i=0; i<sz; i++) {
@@ -344,11 +353,13 @@ ContourCallback gerbolyze::nopencv::simplify_contours_teh_chin(ContourCallback c
             }
         }
 
-        cerr << "pass 3: ";
-        for (size_t i=0; i<sz; i++) {
-            cerr << (retain[i] ? "#" : ".");
+        if (debug) {
+            cerr << "pass 3: ";
+            for (size_t i=0; i<sz; i++) {
+                cerr << (retain[i] ? "#" : ".");
+            }
+            cerr << endl;
         }
-        cerr << endl;
 
         Polygon_i new_poly;
         for (size_t i=0; i<sz; i++) {
@@ -356,7 +367,10 @@ ContourCallback gerbolyze::nopencv::simplify_contours_teh_chin(ContourCallback c
                 new_poly.push_back(poly[i]);
             }
         }
-        cb(new_poly, cpol);
+        
+        if (!new_poly.empty()) {
+            cb(new_poly, cpol);
+        }
     };
 }
 
diff --git a/svg-flatten/src/nopencv_test.cpp b/svg-flatten/src/nopencv_test.cpp
index 4027072..389de60 100644
--- a/svg-flatten/src/nopencv_test.cpp
+++ b/svg-flatten/src/nopencv_test.cpp
@@ -29,6 +29,40 @@ private:
     filesystem::path m_path;
 };
 
+class SVGPolyRenderer {
+public:
+    SVGPolyRenderer(const char *fn, int width_px, int height_px)
+        : m_svg(fn) {
+        m_svg << "<svg width=\"" << width_px << "px\" height=\"" << height_px << "px\" viewBox=\"0 0 "
+            << width_px << " " << height_px << "\" "
+            << "xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\">" << endl;
+        m_svg << "<rect width=\"100%\" height=\"100%\" fill=\"black\"/>" << endl;
+    }
+
+    ContourCallback callback() {
+        return [this](Polygon_i &poly, ContourPolarity pol) {
+            mu_assert(poly.size() > 0, "Empty contour returned");
+            mu_assert(poly.size() > 2, "Contour has less than three points, no area");
+            mu_assert(pol == CP_CONTOUR || pol == CP_HOLE, "Contour has invalid polarity");
+
+            m_svg << "<path fill=\"" << ((pol == CP_HOLE) ? "black" : "white") << "\" d=\"";
+            m_svg << "M " << poly[0][0] << " " << poly[0][1];
+            for (size_t i=1; i<poly.size(); i++) {
+                m_svg << " L " << poly[i][0] << " " << poly[i][1];
+            }
+            m_svg << " Z\"/>" << endl;
+        };
+    }
+
+    void close() {
+        m_svg << "</svg>" << endl;
+        m_svg.close();
+    }
+
+private:
+    ofstream m_svg;
+};
+
 MU_TEST(test_complex_example_from_paper) {
     int32_t img_data[6*9] = {
         0, 0, 0, 0, 0, 0, 0, 0, 0,
@@ -74,16 +108,13 @@ MU_TEST(test_complex_example_from_paper) {
             i2p last;
             bool first = true;
             Polygon_i exp = expected_polys[invocation_count-1];
-            //cout << "poly: ";
             for (auto &p : poly) {
-                //cout << "(" << p[0] << ", " << p[1] << "), ";
                 if (!first) {
                     mu_assert((fabs(p[0] - last[0]) + fabs(p[1] - last[1]) == 1), "Subsequent contour points have distance other than one");
                     mu_assert(find(exp.begin(), exp.end(), p) != exp.end(), "Got unexpected contour point");
                 }
                 last = p;
             }
-            //cout << endl;
         });
     mu_assert_int_eq(3, invocation_count);
 
@@ -127,6 +158,27 @@ MU_TEST(test_complex_example_from_paper) {
     }
 }
 
+int render_svg(const char *in_svg, const char *out_png) {
+    const char *command_line[] = {"resvg", in_svg, out_png, nullptr};
+    struct subprocess_s subprocess;
+    int rc = subprocess_create(command_line, subprocess_option_inherit_environment, &subprocess);
+    if (rc)
+        return rc;
+
+    int resvg_rc = -1;
+    rc = subprocess_join(&subprocess, &resvg_rc);
+    if (rc)
+        return rc;
+    if (resvg_rc)
+        return -resvg_rc;
+
+    rc = subprocess_destroy(&subprocess);
+    if (rc)
+        return rc;
+
+    return 0;
+}
+
 static void testdata_roundtrip(const char *fn) {
     int x, y;
     uint8_t *data = stbi_load(fn, &x, &y, nullptr, 1);
@@ -142,40 +194,11 @@ static void testdata_roundtrip(const char *fn) {
     TempfileHack tmp_svg(".svg");
     TempfileHack tmp_png(".png");
 
-    ofstream svg(tmp_svg.c_str());
-
-    svg << "<svg width=\"" << x << "px\" height=\"" << y << "px\" viewBox=\"0 0 "
-        << x << " " << y << "\" "
-        << "xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\">" << endl;
-    svg << "<rect width=\"100%\" height=\"100%\" fill=\"black\"/>" << endl;
-
-    gerbolyze::nopencv::find_blobs(ref_img, [&svg](Polygon_i &poly, ContourPolarity pol) {
-        mu_assert(poly.size() > 0, "Empty contour returned");
-        mu_assert(poly.size() > 2, "Contour has less than three points, no area");
-        mu_assert(pol == CP_CONTOUR || pol == CP_HOLE, "Contour has invalid polarity");
+    SVGPolyRenderer ctx(tmp_svg.c_str(), x, y);
+    gerbolyze::nopencv::find_blobs(ref_img, ctx.callback());
+    ctx.close();
 
-        svg << "<path fill=\"" << ((pol == CP_HOLE) ? "black" : "white") << "\" d=\"";
-        svg << "M " << poly[0][0] << " " << poly[0][1];
-        for (size_t i=1; i<poly.size(); i++) {
-            svg << " L " << poly[i][0] << " " << poly[i][1];
-        }
-        svg << " Z\"/>" << endl;
-    });
-    svg << "</svg>" << endl;
-    svg.close();
-
-    const char *command_line[] = {"resvg", tmp_svg.c_str(), tmp_png.c_str()};
-    struct subprocess_s subprocess;
-    int rc = subprocess_create(command_line, subprocess_option_inherit_environment, &subprocess);
-    mu_assert_int_eq(0, rc);
-
-    int resvg_rc = -1;
-    rc = subprocess_join(&subprocess, &resvg_rc);
-    mu_assert_int_eq(0, rc);
-    mu_assert_int_eq(0, resvg_rc);
-
-    rc = subprocess_destroy(&subprocess);
-    mu_assert_int_eq(0, rc);
+    mu_assert_int_eq(0, render_svg(tmp_svg.c_str(), tmp_png.c_str()));
 
     int out_x, out_y;
     uint8_t *out_data = stbi_load(tmp_png.c_str(), &out_x, &out_y, nullptr, 1);
@@ -213,44 +236,77 @@ MU_TEST(test_round_trip_two_px_inv)         { testdata_roundtrip("testdata/two-p
 
 
 static void chain_approx_test(const char *fn) {
-    int x, y;
-    uint8_t *data = stbi_load(fn, &x, &y, nullptr, 1);
-    Image32 ref_img(x, y);
-    for (int cy=0; cy<y; cy++) {
-        for (int cx=0; cx<x; cx++) {
-            ref_img.at(cx, cy) = data[cy*x + cx] / 255;
+    //cout << endl << "Testing \"" << fn << "\"" << endl;
+    int w, h;
+    uint8_t *data = stbi_load(fn, &w, &h, nullptr, 1);
+    Image32 ref_img(w, h);
+    for (int y=0; y<h; y++) {
+        for (int x=0; x<w; x++) {
+            ref_img.at(x, y) = data[y*w + x] / 255;
         }
     }
-    stbi_image_free(data);
 
     TempfileHack tmp_svg(".svg");
+    TempfileHack tmp_png(".png");
 
-    //ofstream svg(tmp_svg.c_str());
-    ofstream svg("/tmp/teh-chin-test.svg");
-
-    svg << "<svg width=\"" << x << "px\" height=\"" << y << "px\" viewBox=\"0 0 "
-        << x << " " << y << "\" "
-        << "xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\">" << endl;
-    svg << "<rect width=\"100%\" height=\"100%\" fill=\"black\"/>" << endl;
-
-    gerbolyze::nopencv::find_blobs(ref_img, simplify_contours_teh_chin([&svg](Polygon_i &poly, ContourPolarity pol) {
-        svg << "<path fill=\"" << ((pol == CP_HOLE) ? "black" : "white") << "\" d=\"";
-        svg << "M " << poly[0][0] << " " << poly[0][1];
-        for (size_t i=1; i<poly.size(); i++) {
-            svg << " L " << poly[i][0] << " " << poly[i][1];
+    SVGPolyRenderer ctx(tmp_svg.c_str(), w, h);
+    gerbolyze::nopencv::find_blobs(ref_img, simplify_contours_teh_chin(ctx.callback()));
+    ctx.close();
+
+    mu_assert_int_eq(0, render_svg(tmp_svg.c_str(), "/tmp/out.png"));
+
+    int out_w, out_h;
+    uint8_t *out_data = stbi_load("/tmp/out.png", &out_w, &out_h, nullptr, 1);
+    mu_assert_int_eq(w, out_w);
+    mu_assert_int_eq(h, out_h);
+
+    double max_abs_deviation = 0;
+    double rms_sum = 0; 
+    double mean_sum = 0; 
+    for (int y=0; y<h; y++) {
+        for (int x=0; x<w; x++) {
+            double delta = fabs((double)out_data[y*w + x] - (double)data[y*w + x]) / 255.0;
+            max_abs_deviation = fmax(max_abs_deviation, delta);
+            rms_sum += delta*delta;
+            mean_sum += delta;
         }
-        svg << " Z\"/>" << endl;
-    }));
-    svg << "</svg>" << endl;
-    svg.close();
+    }
+    stbi_image_free(data);
+    stbi_image_free(out_data);
+
+    rms_sum = sqrt(rms_sum / (w*h));
+    mean_sum /= w*h;
+    if (rms_sum > 0.5) {
+        snprintf(msg, sizeof(msg), "%s: Chain approximation RMS error is above threshold: %.3f > 0.5\n", fn, rms_sum);
+        mu_fail(msg);
+    }
+    if (mean_sum > 0.1) {
+        snprintf(msg, sizeof(msg), "%s: Chain approximation mean error is above threshold: %.3f > 0.1\n", fn, mean_sum);
+        mu_fail(msg);
+    }
+    //mu_assert(max_abs_deviation < 0.5, "Maximum chain approximation error is above threshold");
 }
 
 
 MU_TEST(chain_approx_test_chromosome)         { chain_approx_test("testdata/chain-approx-teh-chin-chromosome.png"); }
+MU_TEST(chain_approx_test_blank)              { chain_approx_test("testdata/blank.png"); }
+MU_TEST(chain_approx_test_white)              { chain_approx_test("testdata/white.png"); }
+MU_TEST(chain_approx_test_blob_border_w)      { chain_approx_test("testdata/blob-border-w.png"); }
+MU_TEST(chain_approx_test_blobs_borders)      { chain_approx_test("testdata/blobs-borders.png"); }
+MU_TEST(chain_approx_test_blobs_corners)      { chain_approx_test("testdata/blobs-corners.png"); }
+MU_TEST(chain_approx_test_blobs_crossing)     { chain_approx_test("testdata/blobs-crossing.png"); }
+MU_TEST(chain_approx_test_cross)              { chain_approx_test("testdata/cross.png"); }
+MU_TEST(chain_approx_test_letter_e)           { chain_approx_test("testdata/letter-e.png"); }
+MU_TEST(chain_approx_test_paper_example)      { chain_approx_test("testdata/paper-example.png"); }
+MU_TEST(chain_approx_test_paper_example_inv)  { chain_approx_test("testdata/paper-example-inv.png"); }
+MU_TEST(chain_approx_test_single_px)          { chain_approx_test("testdata/single-px.png"); }
+MU_TEST(chain_approx_test_single_px_inv)      { chain_approx_test("testdata/single-px-inv.png"); }
+MU_TEST(chain_approx_test_two_blobs)          { chain_approx_test("testdata/two-blobs.png"); }
+MU_TEST(chain_approx_test_two_px)             { chain_approx_test("testdata/two-px.png"); }
+MU_TEST(chain_approx_test_two_px_inv)         { chain_approx_test("testdata/two-px-inv.png"); }
 
 
 MU_TEST_SUITE(nopencv_contours_suite) {
-    /*
     MU_RUN_TEST(test_complex_example_from_paper);
     MU_RUN_TEST(test_round_trip_blank);
     MU_RUN_TEST(test_round_trip_white);
@@ -267,8 +323,22 @@ MU_TEST_SUITE(nopencv_contours_suite) {
     MU_RUN_TEST(test_round_trip_two_blobs);
     MU_RUN_TEST(test_round_trip_two_px);
     MU_RUN_TEST(test_round_trip_two_px_inv);
-    */
     MU_RUN_TEST(chain_approx_test_chromosome);
+    MU_RUN_TEST(chain_approx_test_blank);
+    MU_RUN_TEST(chain_approx_test_white);
+    MU_RUN_TEST(chain_approx_test_blob_border_w);
+    MU_RUN_TEST(chain_approx_test_blobs_borders);
+    MU_RUN_TEST(chain_approx_test_blobs_corners);
+    MU_RUN_TEST(chain_approx_test_blobs_crossing);
+    MU_RUN_TEST(chain_approx_test_cross);
+    MU_RUN_TEST(chain_approx_test_letter_e);
+    MU_RUN_TEST(chain_approx_test_paper_example);
+    MU_RUN_TEST(chain_approx_test_paper_example_inv);
+    MU_RUN_TEST(chain_approx_test_single_px);
+    MU_RUN_TEST(chain_approx_test_single_px_inv);
+    MU_RUN_TEST(chain_approx_test_two_blobs);
+    MU_RUN_TEST(chain_approx_test_two_px);
+    MU_RUN_TEST(chain_approx_test_two_px_inv);
 };
 
 int main(int argc, char **argv) {