added some visualization tools for lidar pointclouds

tools/util.py

@@ -0,0 +1,67 @@
+from pointcloudset import Dataset
+from pathlib import Path
+from argparse import ArgumentTypeError
+from subprocess import run
+from datetime import timedelta
+from matplotlib.colors import Colormap
+from matplotlib import colormaps
+
+
+def load_dataset_from_bag(bag_file_path: Path, pointcloud_topic: str = "/ouster/points") -> Dataset:
+    return Dataset.from_file(bag_file_path, topic=pointcloud_topic)
+
+
+def calculate_average_frame_rate(dataset: Dataset):
+    timestamps = dataset.timestamps
+    time_deltas = [timestamps[i + 1] - timestamps[i] for i in range(len(timestamps) - 1)]
+    average_delta = sum(time_deltas, timedelta()) / len(time_deltas)
+    average_frame_rate = 1 / average_delta.total_seconds()
+    return average_frame_rate
+
+
+def existing_file(path_string: str) -> Path:
+    path = Path(path_string)
+    if not path.exists():
+        raise ArgumentTypeError(f"{path} does not exist!")
+    if not path.is_file():
+        raise ArgumentTypeError(f"{path} is not a valid file!")
+    return path
+
+
+def existing_folder(path_string: str) -> Path:
+    path = Path(path_string)
+    if not path.exists():
+        raise ArgumentTypeError(f"{path} does not exist!")
+    if not path.is_folder():
+        raise ArgumentTypeError(f"{path} is not a valid folder!")
+    return path
+
+
+def get_colormap_with_special_missing_color(
+    colormap_name: str, missing_data_color: str = "black", reverse: bool = False
+) -> Colormap:
+    colormap = colormaps[colormap_name] if not reverse else colormaps[f"{colormap_name}_r"]
+    colormap.set_bad(missing_data_color)
+    return colormap
+
+
+def create_video_from_images(input_images_pattern: str, output_file: Path, frame_rate: int) -> None:
+    # Construct the ffmpeg command
+    command = [
+        "ffmpeg",
+        "-y",
+        "-framerate",
+        str(frame_rate),
+        "-i",
+        input_images_pattern,
+        "-c:v",
+        "libx264",
+        "-profile:v",
+        "high",
+        "-crf",
+        "20",
+        "-pix_fmt",
+        "yuv420p",
+        output_file.as_posix(),
+    ]
+    run(command, check=True)