save sfm depth as png to keep 16bit. save depth_file_path as relative… (#2317)

save sfm depth as png to keep 16bit. save depth_file_path as relative path

Co-authored-by: Matthew Tancik <matt@lumalabs.ai>

nerfstudio/process_data/colmap_utils.py

@@ -441,7 +441,7 @@ def colmap_to_json(
             frame["mask_path"] = camera_mask_path.relative_to(camera_mask_path.parent.parent).as_posix()
         if image_id_to_depth_path is not None:
             depth_path = image_id_to_depth_path[im_id]
-            frame["depth_file_path"] = str(depth_path)
+            frame["depth_file_path"] = str(depth_path.relative_to(depth_path.parent.parent))
         frames.append(frame)
 
     if set(cam_id_to_camera.keys()) != {1}:
@@ -582,6 +582,8 @@ def create_sfm_depth(
 
         out_name = str(im_data.name)
         depth_path = output_dir / out_name
+        if depth_path.suffix == ".jpg":
+            depth_path = depth_path.with_suffix(".png")
         cv2.imwrite(str(depth_path), depth_img)  # type: ignore
 
         image_id_to_depth_path[im_id] = depth_path