Fix inner/outer detection in contour tracing

examples/contours.rs

@@ -1,30 +1,38 @@
 mod common;
 
+use ccvl::kernel::Kernel;
 use ccvl::*;
 
-fn draw(contour: &contour::Contour, img: &mut image::Image<image::SRGBA>) {
-    let n = contour.vertices.len();
+fn draw(
+    img: &mut image::Image<image::SRGBA>,
+    path: &Vec<(usize, usize)>,
+    colour: image::SRGBA,
+) {
+    let n = path.len();
     for i in 0..n {
-        let (x0, y0) = contour.vertices[i];
-        let (x1, y1) = contour.vertices[(i + 1) % n];
-        let colour = match contour.kind {
-            contour::Kind::Outer => colours::GREEN,
-            contour::Kind::Inner => colours::BLUE,
-        };
+        let (x0, y0) = path[i];
+        let (x1, y1) = path[(i + 1) % n];
         draw::line(x0, y0, x1, y1, img, colour);
     }
 }
 
+fn approx(a: f32, b: f32, epsilon: f32) -> bool {
+    (a - b).abs() <= epsilon
+}
+
 fn main() -> std::process::ExitCode {
     common::process_image(|mut img| {
         let greyscale = img.map(|p| image::Luminance::from(p));
-        let thresholded = filter::threshold_auto(greyscale);
-
-        let contours = contour::find(thresholded);
+        let blurred = kernel::gaussian::<5>(1.2).convolve_sat(&greyscale);
+        let thresholded = filter::threshold_auto(blurred);
+        let contours =
+            contour::find(&thresholded, image::Luminance { y: 0.0 });
         for contour in contours {
-            draw(&contour, &mut img);
+            draw(&mut img, &contour.vertices, match contour.kind {
+				contour::Kind::Outer => colours::GREEN,
+				contour::Kind::Inner => colours::BLUE,
+			});
         }
-
         img
     })
 }