code: def _filter_boxes(boxes, min_size):
      """Remove all boxes with any side smaller than min_size."""
      ws = boxes[:, 2] - boxes[:, 0] + 1
      hs = boxes[:, 3] - boxes[:, 1] + 1
      keep = np.where((ws >= min_size) & (hs >= min_size))[0]
      return keep
  
file_path: CNTK/Examples/Image/Detection/utils/caffe_layers/proposal_layer.py
imports: import numpy
  import yaml
  from utils.caffe_layers.default_config import cfg
  from utils.rpn.generate_anchors import generate_anchors
  from utils.caffe_layers.bbox_transform import bbox_transform_inv, clip_boxes
  from utils.nms_wrapper import nms
label_desc: Use image node_id 1 for calling a global function with example usage: _filter_boxes(boxes, min_size) and returns: keep