Added some code.

.gitignore

@@ -3,3 +3,4 @@ env
 .idea
 .DS_Store
 *.pt
+*.png

dodgeballtracker/logic.py

@@ -63,6 +63,31 @@ def crazy_experiment(frame):
     cv2.polylines(frame, pts, True, (0, 255, 255), 8)
 
 
+def get_court_perspective_transform():
+    """
+    """
+    empirical_top_left = np.float32([416, 175])
+    empirical_top_right = np.float32([905, 173])
+    empirical_bottom_left = np.float32([51, 702])
+    empirical_bottom_right = np.float32([1188, 695])
+
+    court_top_left = np.float32([0, 0])
+    court_top_right = np.float32([9, 0])
+    court_bottom_left = np.float32([0, 18])
+    court_bottom_right = np.float32([9, 18])
+
+    empirical_source = np.float32([empirical_top_left,
+                                  empirical_top_right,
+                                  empirical_bottom_left,
+                                  empirical_bottom_right])
+    pixel_per_meter = 50
+    empirical_target = np.float32([court_top_left,
+                                  court_top_right,
+                                  court_bottom_left,
+                                  court_bottom_right]) * pixel_per_meter
+    return cv2.getPerspectiveTransform(empirical_source, empirical_target)
+
+
 def main(input_filename: Path, output_filename: Path, detected_box_objects):
     # define some constants
     detected_box_objects = sorted(detected_box_objects, reverse=True)

frontend/style.css

@@ -1,11 +1,12 @@
 .court-border {
     stroke: red;
     stroke-width: 4px;
-    fill-opacity: 0;
+    /*fill-opacity: 0;*/
+    fill: gray;
 }
 
 .return-line {
-    stroke: yellow;
+    stroke: blue;
     stroke-width: 2px;
     fill-opacity: 0;
 }