code: def read_cameras(cls, cameras_txt_path):
      cameras = {}
      with open(cameras_txt_path, "r") as fid:
          line = fid.readline()
          assert (
              line
              == "# Camera list with one line of data per camera:\n"
          )
          line = fid.readline()
          assert (
              line == "#   CAMERA_ID, MODEL, WIDTH, HEIGHT, PARAMS[]\n"
          )
          line = fid.readline()
          assert re.search("^# Number of cameras: \d+\n$", line)
          num_cams = int(re.findall(r"[-+]?\d*\.\d+|\d+", line)[0])
  
          for _ in tqdm(range(num_cams), desc="reading cameras"):
              elems = fid.readline().split()
              camera_id = int(elems[0])
              if elems[1] == "SIMPLE_RADIAL":
                  width, height, focal_length, cx, cy, radial = list(
                      map(float, elems[2:])
                  )
                  cur_cam = PinholeCamera(
                      width, height, focal_length, focal_length, cx, cy
                  )
              elif elems[1] == "PINHOLE":
                  width, height, fx, fy, cx, cy = list(
                      map(float, elems[2:])
                  )
                  cur_cam = PinholeCamera(width, height, fx, fy, cx, cy)
              elif elems[1] == "OPENCV":
                  width, height, fx, fy, cx, cy, k1, k2, k3, k4 = list(
                      map(float, elems[2:])
                  )
                  cur_cam = PinholeCamera(width, height, fx, fy, cx, cy)
              else:
                  raise ValueError(f"unsupported camera: {elems[1]}")
              assert camera_id not in cameras
              cameras[camera_id] = cur_cam
      return cameras
  
file_path: ml-neuman/data_io/colmap_helper.py
imports: import os
  import re
  from collections import namedtuple
  import numpy
  from tqdm import tqdm
  from geometry.basics import Translation, Rotation
  from cameras.camera_pose import CameraPose
  from cameras.pinhole_camera import PinholeCamera
  from cameras import captures
  from scenes import scene
label_desc: Use image node_id 5 for calling the ColmapAsciiReader obj's underlying member method code with example usage: obj.read_cameras(cls, cameras_txt_path) and returns: cameras