Add pairs_from_sequential.py script for creating image pairs

For faster SFM when using a video, or sequential images

hloc/pairs_from_sequential.py

@@ -0,0 +1,65 @@
+import argparse
+import collections.abc as collections
+from pathlib import Path
+from typing import Optional, Union, List
+
+from . import logger
+from .utils.parsers import parse_image_lists
+from .utils.io import list_h5_names
+# based on https://github.com/hugoycj/light-hloc/blob/e518dbaa06b6b57e5663318cff237066ac26bd08/lighthloc/associators/pairs_from_sequance.py
+
+
+def main(
+    output: Path,
+    image_list: Optional[Union[Path, List[str]]] = None,
+    features: Optional[Path] = None,
+    overlap: Optional[int] = 10,
+    quadratic_overlap: bool = True,
+):
+    if image_list is not None:
+        if isinstance(image_list, (str, Path)):
+            print(image_list)
+            names_q = parse_image_lists(image_list)
+        elif isinstance(image_list, collections.Iterable):
+            names_q = list(image_list)
+        else:
+            raise ValueError(f"Unknown type for image list: {image_list}")
+    elif features is not None:
+        names_q = list_h5_names(features)
+    else:
+        raise ValueError("Provide either a list of images or a feature file.")
+
+    pairs = []
+    N = len(names_q)
+
+    for i in range(N - 1):
+        for j in range(i + 1, min(i + overlap + 1, N)):
+            pairs.append((names_q[i], names_q[j]))
+
+            if quadratic_overlap:
+                q = 2 ** (j - i)
+                if q > overlap and i + q < N:
+                    pairs.append((names_q[i], names_q[i + q]))
+
+    logger.info(f"Found {len(pairs)} pairs.")
+    with open(output, "w") as f:
+        f.write("\n".join(" ".join([i, j]) for i, j in pairs))
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(
+        description="Create a list of image pairs based on the sequence of images on alphabetic order"
+    )
+    parser.add_argument("--output", required=True, type=Path)
+    parser.add_argument("--image_list", type=Path)
+    parser.add_argument("--features", type=Path)
+    parser.add_argument(
+        "--overlap", type=int, default=10, help="Number of overlapping image pairs"
+    )
+    parser.add_argument(
+        "--quadratic_overlap",
+        action="store_true",
+        help="Whether to match images against their quadratic neighbors.",
+    )
+    args = parser.parse_args()
+    main(**args.__dict__)