[calibration] Remove assert checking if image size are equal

* cv2.StereoCalibrate use image size to initialize camera matrix, but it is already give and fixed in this case.

bob/ip/stereo/calibration.py

@@ -125,12 +125,13 @@ def compute_intrinsics(im_pts, image_size, obj_pts=None, ids=None, charuco_board
     return reprojection_error, cam_mat, dist_coefs
 
 
-def compute_relative_extrinsics(obj_pts, im_pts1, cam_m1, dist_1, im_pts2, cam_m2, dist_2, image_size):
+def compute_relative_extrinsics(obj_pts, im_pts1, cam_m1, dist_1, im_pts2, cam_m2, dist_2, image_size=None):
     """ """
     R, T, E, F = None, None, None, None
     criteria = (cv2.TERM_CRITERIA_MAX_ITER + cv2.TERM_CRITERIA_EPS, 1000, 1e-5)
     flags = cv2.CALIB_FIX_INTRINSIC
-    image_size = (image_size[1], image_size[0])
+    # In cv2.stereoCalibrate, image_size is used to initialize the intrinsics matrix. As the intrinsics are
+    # already computed, the flags can be set to cv2.CALIB_FIX_INTRINSIC
     (reprojection_error, _, _, _, _, R, T, E, F) = cv2.stereoCalibrate(
         obj_pts,
         im_pts1,
@@ -483,8 +484,6 @@ def main():
         #     if camera_2 == camera:
         #         continue
 
-        if image_data[reference] != image_size:
-            raise ValueError("Image size between {} and {} does not match.".format(camera, reference))
         if not "df_extrinsics_{}".format(reference) in calibration[camera].keys():
             continue
         df = calibration[camera]["df_extrinsics_{}".format(reference)]
@@ -500,7 +499,7 @@ def main():
             if np.linalg.norm(i1 - i2) != 0.0:
                 raise ValueError("Difference between both ids")
         err, R, T = compute_relative_extrinsics(
-            obj_pts, im_pts1, cam_mat1, dist_coefs1, im_pts2, cam_mat2, dist_coefs2, image_size
+            obj_pts, im_pts1, cam_mat1, dist_coefs1, im_pts2, cam_mat2, dist_coefs2
         )
         H = np.eye(4)
         H[0:3, 0:3] = R