From eb4cb447309c5b0f6bfe1812df711fb8d2e390f5 Mon Sep 17 00:00:00 2001
From: Piero Toffanin <pt@masseranolabs.com>
Date: Fri, 13 Sep 2024 08:28:02 -0400
Subject: [PATCH] Add roundtrip example

---
 cameralib/__init__.py |  3 +++
 examples/roundtrip.py | 18 ++++++++++++++++++
 2 files changed, 21 insertions(+)
 create mode 100644 examples/roundtrip.py

diff --git a/cameralib/__init__.py b/cameralib/__init__.py
index 1d109da..6789b1c 100644
--- a/cameralib/__init__.py
+++ b/cameralib/__init__.py
@@ -23,6 +23,7 @@
  * `Hello World`_
  * `X-AnyLabeling annotations to GeoJSON`_
  * `Yolov7 annotations to GeoJSON`_
+ * `Round Trip`_
 
 Getting Help / Reporting Issues:
 --------------------------------
@@ -44,6 +45,8 @@
    https://github.com/OpenDroneMap/CameraLib/blob/main/examples/anylabeling.py
 .. _Yolov7 annotations to GeoJSON:
    https://github.com/OpenDroneMap/CameraLib/blob/main/examples/yolov7.py
+.. _Round Trip:
+   https://github.com/OpenDroneMap/CameraLib/blob/main/examples/roundtrip.py
 .. _report it:
     https://github.com/OpenDroneMap/CameraLib/issues
 .. _`GitHub`:
diff --git a/examples/roundtrip.py b/examples/roundtrip.py
new file mode 100644
index 0000000..9ea9783
--- /dev/null
+++ b/examples/roundtrip.py
@@ -0,0 +1,18 @@
+import math
+from cameralib import Projector
+from cameralib.tests import get_test_dataset
+
+
+p = Projector(get_test_dataset())
+coords = [46.8423725961765, -91.99395518749954]
+print(f"Input: {coords}")
+
+cams = p.world2cams(*coords)
+for cam in cams:
+    if cam['filename'] == 'DJI_0028.JPG':
+        print(f"X: {cam['x']} Y: {cam['y']}")
+        output = p.cam2world('DJI_0028.JPG', [(cam['x'], cam['y'])])
+        print(f"Output: {output[0]}")
+        rms = math.sqrt((coords[0] - output[0][0]) ** 2 + (coords[1] - output[0][1]) ** 2)
+        print(f"Reprojection error: ~{rms / 7.87e-6} meters")
+