diff --git a/y2019/vision/global_calibration.cc b/y2019/vision/global_calibration.cc
index d5f0d4e..bf64310 100644
--- a/y2019/vision/global_calibration.cc
+++ b/y2019/vision/global_calibration.cc
@@ -133,7 +133,10 @@
     bool verbose = false;
     std::vector<std::vector<Segment<2>>> raw_polys;
     for (const RangeImage &blob : imgs) {
-      std::vector<Segment<2>> polygon = finder_.FillPolygon(blob, verbose);
+      // Convert blobs to contours in the corrected space.
+      ContourNode* contour = finder_.GetContour(blob);
+      finder_.UnWarpContour(contour);
+      std::vector<Segment<2>> polygon = finder_.FillPolygon(contour, verbose);
       if (polygon.empty()) {
       } else {
         raw_polys.push_back(polygon);