class_docstr: Class for image processing. Methods for detecting lines in an image and clustering them. Helper methods for
  drawing.
docstr: Try to find a separator line on double pages. After line detection, find a line in direction <direction> around
  <around_rel_position>.
  Return the 1D line position if a separator line was found, else None.
docstr_tok: ["Try","to","find","a","separator","line","on","double","pages",".","After","line","detection",",","find","a","line","in","direction","<","direction",">","around","<","around_rel_position",">",".","Return","the","1D","line","position","if","a","separator","line","was","found",",","else","None","."]
code: def find_pages_separator_line(
      self,
      direction=DIRECTION_VERTICAL,
      around_rel_position=0.5,
      clustering_method=None,
      **clustering_kwargs,
  ):
      """
      Try to find a separator line on double pages. After line detection, find a line in direction <direction> around
      <around_rel_position>.
      Return the 1D line position if a separator line was found, else None.
      """
  
      if direction not in (DIRECTION_HORIZONTAL, DIRECTION_VERTICAL):
          raise ValueError(
              "invalid value for 'direction': '%s'" % direction
          )
  
      if not 0 <= around_rel_position <= 1:
          raise ValueError(
              "invalid value for 'around_rel_position' (must be in [0, 1]): %d"
              % around_rel_position
          )
  
      line_clusters = self.find_clusters(
          direction,
          clustering_method or find_clusters_1d_break_dist,
          **clustering_kwargs,
      )
  
      if not line_clusters:
          return None
  
      cluster_centers = np.array(calc_cluster_centers_1d(line_clusters))
  
      img_dim = (
          self.img_w if direction == DIRECTION_VERTICAL else self.img_h
      )
      around_pos = img_dim * around_rel_position
  
      sep_idx = np.argmin(np.abs(cluster_centers - around_pos))
  
      return cluster_centers[sep_idx]
  
imports: from logging import warning
  from math import degrees
  import numpy
  import cv2
  from pdftabextract.common import ROTATION, SKEW_X, SKEW_Y, DIRECTION_HORIZONTAL, DIRECTION_VERTICAL
  from pdftabextract.geom import normalize_angle, project_polarcoord_lines
  from pdftabextract.clustering import zip_clusters_and_values, find_clusters_1d_break_dist, calc_cluster_centers_1d
label_desc: Use image node_id 3 for calling the ImageProc obj's underlying member method code with example usage: obj.find_pages_separator_line(direction, around_rel_position, clustering_method) and returns: cluster_centers, None