Improve ns-process-data images when using existing COLMAP model (#1371)

* Allow skipping copy+downscale of images in ns-process-data, fix bug when using --skip-colmap on images.bin with non-standard image names

* Rename flags and improve error messages

---------

Co-authored-by: Matthew Tancik <tancik@berkeley.edu>

nerfstudio/process_data/colmap_utils.py

@@ -604,6 +604,14 @@ def colmap_to_json(
     cameras = read_cameras_binary(cameras_path)
     images = read_images_binary(images_path)
 
+    # Images were renamed to frame_{i:05d}.{ext} and
+    # the filenames needs to be replaced in the transforms.json as well
+    original_filenames = [x.name for x in images.values()]
+    # Sort was used in nerfstudio.process_data.process_data_utils:get_image_filenames
+    original_filenames.sort()
+    # Build the map to the new filenames
+    filename_map = {name: f"frame_{i+1:05d}{os.path.splitext(name)[-1]}" for i, name in enumerate(original_filenames)}
+
     # Only supports one camera
     camera_params = cameras[1].params
 
@@ -619,7 +627,8 @@ def colmap_to_json(
         c2w = c2w[np.array([1, 0, 2, 3]), :]
         c2w[2, :] *= -1
 
-        name = Path(f"./images/{im_data.name}")
+        name = filename_map[im_data.name]
+        name = Path(f"./images/{name}")
 
         frame = {
             "file_path": name.as_posix(),

nerfstudio/process_data/process_data_utils.py

@@ -46,6 +46,19 @@ CAMERA_MODELS = {
 }
 
 
+def list_images(data: Path) -> List[Path]:
+    """Lists all supported images in a directory
+
+    Args:
+        data: Path to the directory of images.
+    Returns:
+        Paths to images contained in the directory
+    """
+    allowed_exts = [".jpg", ".jpeg", ".png", ".tif", ".tiff"]
+    image_paths = sorted([p for p in data.glob("[!.]*") if p.suffix.lower() in allowed_exts])
+    return image_paths
+
+
 def get_image_filenames(directory: Path, max_num_images: int = -1) -> Tuple[List[Path], int]:
     """Returns a list of image filenames in a directory.
 
@@ -55,8 +68,7 @@ def get_image_filenames(directory: Path, max_num_images: int = -1) -> Tuple[List
     Returns:
         A tuple of A list of image filenames, number of original image paths.
     """
-    allowed_exts = [".jpg", ".jpeg", ".png", ".tif", ".tiff"]
-    image_paths = sorted([p for p in directory.glob("[!.]*") if p.suffix.lower() in allowed_exts])
+    image_paths = list_images(directory)
     num_orig_images = len(image_paths)
 
     if max_num_images != -1 and num_orig_images > max_num_images:
@@ -240,8 +252,7 @@ def copy_images(data: Path, image_dir: Path, verbose) -> int:
         The number of images copied.
     """
     with status(msg="[bold yellow]Copying images...", spinner="bouncingBall", verbose=verbose):
-        allowed_exts = [".jpg", ".jpeg", ".png", ".tif", ".tiff"]
-        image_paths = sorted([p for p in data.glob("[!.]*") if p.suffix.lower() in allowed_exts])
+        image_paths = list_images(data)
 
         if len(image_paths) == 0:
             CONSOLE.log("[bold red]:skull: No usable images in the data folder.")