458 lines
17 KiB
Python
458 lines
17 KiB
Python
# Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""Contains various CTC decoders."""
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from __future__ import absolute_import
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from __future__ import division
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from __future__ import print_function
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import cv2
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import math
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import numpy as np
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from itertools import groupby
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from skimage.morphology._skeletonize import thin
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def get_dict(character_dict_path):
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character_str = ""
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with open(character_dict_path, "rb") as fin:
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lines = fin.readlines()
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for line in lines:
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line = line.decode('utf-8').strip("\n").strip("\r\n")
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character_str += line
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dict_character = list(character_str)
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return dict_character
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def softmax(logits):
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"""
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logits: N x d
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"""
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max_value = np.max(logits, axis=1, keepdims=True)
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exp = np.exp(logits - max_value)
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exp_sum = np.sum(exp, axis=1, keepdims=True)
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dist = exp / exp_sum
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return dist
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def get_keep_pos_idxs(labels, remove_blank=None):
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"""
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Remove duplicate and get pos idxs of keep items.
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The value of keep_blank should be [None, 95].
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"""
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duplicate_len_list = []
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keep_pos_idx_list = []
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keep_char_idx_list = []
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for k, v_ in groupby(labels):
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current_len = len(list(v_))
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if k != remove_blank:
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current_idx = int(sum(duplicate_len_list) + current_len // 2)
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keep_pos_idx_list.append(current_idx)
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keep_char_idx_list.append(k)
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duplicate_len_list.append(current_len)
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return keep_char_idx_list, keep_pos_idx_list
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def remove_blank(labels, blank=0):
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new_labels = [x for x in labels if x != blank]
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return new_labels
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def insert_blank(labels, blank=0):
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new_labels = [blank]
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for l in labels:
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new_labels += [l, blank]
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return new_labels
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def ctc_greedy_decoder(probs_seq, blank=95, keep_blank_in_idxs=True):
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"""
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CTC greedy (best path) decoder.
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"""
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raw_str = np.argmax(np.array(probs_seq), axis=1)
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remove_blank_in_pos = None if keep_blank_in_idxs else blank
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dedup_str, keep_idx_list = get_keep_pos_idxs(
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raw_str, remove_blank=remove_blank_in_pos)
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dst_str = remove_blank(dedup_str, blank=blank)
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return dst_str, keep_idx_list
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def instance_ctc_greedy_decoder(gather_info, logits_map, pts_num=4):
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_, _, C = logits_map.shape
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ys, xs = zip(*gather_info)
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logits_seq = logits_map[list(ys), list(xs)]
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probs_seq = logits_seq
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labels = np.argmax(probs_seq, axis=1)
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dst_str = [k for k, v_ in groupby(labels) if k != C - 1]
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detal = len(gather_info) // (pts_num - 1)
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keep_idx_list = [0] + [detal * (i + 1) for i in range(pts_num - 2)] + [-1]
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keep_gather_list = [gather_info[idx] for idx in keep_idx_list]
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return dst_str, keep_gather_list
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def ctc_decoder_for_image(gather_info_list,
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logits_map,
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Lexicon_Table,
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pts_num=6):
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"""
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CTC decoder using multiple processes.
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"""
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decoder_str = []
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decoder_xys = []
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for gather_info in gather_info_list:
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if len(gather_info) < pts_num:
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continue
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dst_str, xys_list = instance_ctc_greedy_decoder(
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gather_info, logits_map, pts_num=pts_num)
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dst_str_readable = ''.join([Lexicon_Table[idx] for idx in dst_str])
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if len(dst_str_readable) < 2:
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continue
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decoder_str.append(dst_str_readable)
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decoder_xys.append(xys_list)
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return decoder_str, decoder_xys
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def sort_with_direction(pos_list, f_direction):
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"""
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f_direction: h x w x 2
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pos_list: [[y, x], [y, x], [y, x] ...]
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"""
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def sort_part_with_direction(pos_list, point_direction):
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pos_list = np.array(pos_list).reshape(-1, 2)
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point_direction = np.array(point_direction).reshape(-1, 2)
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average_direction = np.mean(point_direction, axis=0, keepdims=True)
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pos_proj_leng = np.sum(pos_list * average_direction, axis=1)
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sorted_list = pos_list[np.argsort(pos_proj_leng)].tolist()
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sorted_direction = point_direction[np.argsort(pos_proj_leng)].tolist()
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return sorted_list, sorted_direction
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pos_list = np.array(pos_list).reshape(-1, 2)
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point_direction = f_direction[pos_list[:, 0], pos_list[:, 1]] # x, y
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point_direction = point_direction[:, ::-1] # x, y -> y, x
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sorted_point, sorted_direction = sort_part_with_direction(pos_list,
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point_direction)
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point_num = len(sorted_point)
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if point_num >= 16:
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middle_num = point_num // 2
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first_part_point = sorted_point[:middle_num]
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first_point_direction = sorted_direction[:middle_num]
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sorted_fist_part_point, sorted_fist_part_direction = sort_part_with_direction(
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first_part_point, first_point_direction)
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last_part_point = sorted_point[middle_num:]
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last_point_direction = sorted_direction[middle_num:]
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sorted_last_part_point, sorted_last_part_direction = sort_part_with_direction(
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last_part_point, last_point_direction)
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sorted_point = sorted_fist_part_point + sorted_last_part_point
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sorted_direction = sorted_fist_part_direction + sorted_last_part_direction
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return sorted_point, np.array(sorted_direction)
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def add_id(pos_list, image_id=0):
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"""
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Add id for gather feature, for inference.
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"""
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new_list = []
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for item in pos_list:
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new_list.append((image_id, item[0], item[1]))
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return new_list
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def sort_and_expand_with_direction(pos_list, f_direction):
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"""
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f_direction: h x w x 2
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pos_list: [[y, x], [y, x], [y, x] ...]
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"""
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h, w, _ = f_direction.shape
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sorted_list, point_direction = sort_with_direction(pos_list, f_direction)
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point_num = len(sorted_list)
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sub_direction_len = max(point_num // 3, 2)
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left_direction = point_direction[:sub_direction_len, :]
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right_dirction = point_direction[point_num - sub_direction_len:, :]
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left_average_direction = -np.mean(left_direction, axis=0, keepdims=True)
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left_average_len = np.linalg.norm(left_average_direction)
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left_start = np.array(sorted_list[0])
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left_step = left_average_direction / (left_average_len + 1e-6)
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right_average_direction = np.mean(right_dirction, axis=0, keepdims=True)
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right_average_len = np.linalg.norm(right_average_direction)
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right_step = right_average_direction / (right_average_len + 1e-6)
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right_start = np.array(sorted_list[-1])
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append_num = max(
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int((left_average_len + right_average_len) / 2.0 * 0.15), 1)
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left_list = []
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right_list = []
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for i in range(append_num):
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ly, lx = np.round(left_start + left_step * (i + 1)).flatten().astype(
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'int32').tolist()
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if ly < h and lx < w and (ly, lx) not in left_list:
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left_list.append((ly, lx))
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ry, rx = np.round(right_start + right_step * (i + 1)).flatten().astype(
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'int32').tolist()
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if ry < h and rx < w and (ry, rx) not in right_list:
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right_list.append((ry, rx))
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all_list = left_list[::-1] + sorted_list + right_list
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return all_list
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def sort_and_expand_with_direction_v2(pos_list, f_direction, binary_tcl_map):
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"""
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f_direction: h x w x 2
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pos_list: [[y, x], [y, x], [y, x] ...]
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binary_tcl_map: h x w
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"""
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h, w, _ = f_direction.shape
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sorted_list, point_direction = sort_with_direction(pos_list, f_direction)
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point_num = len(sorted_list)
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sub_direction_len = max(point_num // 3, 2)
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left_direction = point_direction[:sub_direction_len, :]
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right_dirction = point_direction[point_num - sub_direction_len:, :]
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left_average_direction = -np.mean(left_direction, axis=0, keepdims=True)
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left_average_len = np.linalg.norm(left_average_direction)
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left_start = np.array(sorted_list[0])
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left_step = left_average_direction / (left_average_len + 1e-6)
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right_average_direction = np.mean(right_dirction, axis=0, keepdims=True)
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right_average_len = np.linalg.norm(right_average_direction)
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right_step = right_average_direction / (right_average_len + 1e-6)
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right_start = np.array(sorted_list[-1])
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append_num = max(
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int((left_average_len + right_average_len) / 2.0 * 0.15), 1)
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max_append_num = 2 * append_num
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left_list = []
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right_list = []
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for i in range(max_append_num):
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ly, lx = np.round(left_start + left_step * (i + 1)).flatten().astype(
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'int32').tolist()
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if ly < h and lx < w and (ly, lx) not in left_list:
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if binary_tcl_map[ly, lx] > 0.5:
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left_list.append((ly, lx))
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else:
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break
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for i in range(max_append_num):
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ry, rx = np.round(right_start + right_step * (i + 1)).flatten().astype(
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'int32').tolist()
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if ry < h and rx < w and (ry, rx) not in right_list:
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if binary_tcl_map[ry, rx] > 0.5:
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right_list.append((ry, rx))
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else:
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break
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all_list = left_list[::-1] + sorted_list + right_list
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return all_list
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def point_pair2poly(point_pair_list):
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"""
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Transfer vertical point_pairs into poly point in clockwise.
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"""
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point_num = len(point_pair_list) * 2
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point_list = [0] * point_num
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for idx, point_pair in enumerate(point_pair_list):
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point_list[idx] = point_pair[0]
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point_list[point_num - 1 - idx] = point_pair[1]
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return np.array(point_list).reshape(-1, 2)
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def shrink_quad_along_width(quad, begin_width_ratio=0., end_width_ratio=1.):
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ratio_pair = np.array(
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[[begin_width_ratio], [end_width_ratio]], dtype=np.float32)
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p0_1 = quad[0] + (quad[1] - quad[0]) * ratio_pair
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p3_2 = quad[3] + (quad[2] - quad[3]) * ratio_pair
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return np.array([p0_1[0], p0_1[1], p3_2[1], p3_2[0]])
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def expand_poly_along_width(poly, shrink_ratio_of_width=0.3):
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"""
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expand poly along width.
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"""
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point_num = poly.shape[0]
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left_quad = np.array(
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[poly[0], poly[1], poly[-2], poly[-1]], dtype=np.float32)
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left_ratio = -shrink_ratio_of_width * np.linalg.norm(left_quad[0] - left_quad[3]) / \
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(np.linalg.norm(left_quad[0] - left_quad[1]) + 1e-6)
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left_quad_expand = shrink_quad_along_width(left_quad, left_ratio, 1.0)
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right_quad = np.array(
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[
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poly[point_num // 2 - 2], poly[point_num // 2 - 1],
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poly[point_num // 2], poly[point_num // 2 + 1]
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],
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dtype=np.float32)
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right_ratio = 1.0 + shrink_ratio_of_width * np.linalg.norm(right_quad[0] - right_quad[3]) / \
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(np.linalg.norm(right_quad[0] - right_quad[1]) + 1e-6)
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right_quad_expand = shrink_quad_along_width(right_quad, 0.0, right_ratio)
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poly[0] = left_quad_expand[0]
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poly[-1] = left_quad_expand[-1]
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poly[point_num // 2 - 1] = right_quad_expand[1]
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poly[point_num // 2] = right_quad_expand[2]
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return poly
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def restore_poly(instance_yxs_list, seq_strs, p_border, ratio_w, ratio_h, src_w,
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src_h, valid_set):
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poly_list = []
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keep_str_list = []
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for yx_center_line, keep_str in zip(instance_yxs_list, seq_strs):
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if len(keep_str) < 2:
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print('--> too short, {}'.format(keep_str))
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continue
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offset_expand = 1.0
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if valid_set == 'totaltext':
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offset_expand = 1.2
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point_pair_list = []
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for y, x in yx_center_line:
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offset = p_border[:, y, x].reshape(2, 2) * offset_expand
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ori_yx = np.array([y, x], dtype=np.float32)
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point_pair = (ori_yx + offset)[:, ::-1] * 4.0 / np.array(
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[ratio_w, ratio_h]).reshape(-1, 2)
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point_pair_list.append(point_pair)
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detected_poly = point_pair2poly(point_pair_list)
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detected_poly = expand_poly_along_width(
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detected_poly, shrink_ratio_of_width=0.2)
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detected_poly[:, 0] = np.clip(detected_poly[:, 0], a_min=0, a_max=src_w)
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detected_poly[:, 1] = np.clip(detected_poly[:, 1], a_min=0, a_max=src_h)
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keep_str_list.append(keep_str)
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if valid_set == 'partvgg':
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middle_point = len(detected_poly) // 2
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detected_poly = detected_poly[
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[0, middle_point - 1, middle_point, -1], :]
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poly_list.append(detected_poly)
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elif valid_set == 'totaltext':
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poly_list.append(detected_poly)
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else:
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print('--> Not supported format.')
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exit(-1)
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return poly_list, keep_str_list
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def generate_pivot_list_fast(p_score,
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p_char_maps,
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f_direction,
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Lexicon_Table,
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score_thresh=0.5):
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"""
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return center point and end point of TCL instance; filter with the char maps;
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"""
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p_score = p_score[0]
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f_direction = f_direction.transpose(1, 2, 0)
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p_tcl_map = (p_score > score_thresh) * 1.0
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skeleton_map = thin(p_tcl_map.astype(np.uint8))
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instance_count, instance_label_map = cv2.connectedComponents(
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skeleton_map.astype(np.uint8), connectivity=8)
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# get TCL Instance
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all_pos_yxs = []
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if instance_count > 0:
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for instance_id in range(1, instance_count):
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pos_list = []
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ys, xs = np.where(instance_label_map == instance_id)
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pos_list = list(zip(ys, xs))
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if len(pos_list) < 3:
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continue
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pos_list_sorted = sort_and_expand_with_direction_v2(
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pos_list, f_direction, p_tcl_map)
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all_pos_yxs.append(pos_list_sorted)
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p_char_maps = p_char_maps.transpose([1, 2, 0])
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decoded_str, keep_yxs_list = ctc_decoder_for_image(
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all_pos_yxs, logits_map=p_char_maps, Lexicon_Table=Lexicon_Table)
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return keep_yxs_list, decoded_str
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def extract_main_direction(pos_list, f_direction):
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"""
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f_direction: h x w x 2
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pos_list: [[y, x], [y, x], [y, x] ...]
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"""
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pos_list = np.array(pos_list)
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point_direction = f_direction[pos_list[:, 0], pos_list[:, 1]]
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point_direction = point_direction[:, ::-1] # x, y -> y, x
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average_direction = np.mean(point_direction, axis=0, keepdims=True)
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average_direction = average_direction / (
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np.linalg.norm(average_direction) + 1e-6)
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return average_direction
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def sort_by_direction_with_image_id_deprecated(pos_list, f_direction):
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"""
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f_direction: h x w x 2
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pos_list: [[id, y, x], [id, y, x], [id, y, x] ...]
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"""
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pos_list_full = np.array(pos_list).reshape(-1, 3)
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pos_list = pos_list_full[:, 1:]
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point_direction = f_direction[pos_list[:, 0], pos_list[:, 1]] # x, y
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point_direction = point_direction[:, ::-1] # x, y -> y, x
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average_direction = np.mean(point_direction, axis=0, keepdims=True)
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pos_proj_leng = np.sum(pos_list * average_direction, axis=1)
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sorted_list = pos_list_full[np.argsort(pos_proj_leng)].tolist()
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return sorted_list
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def sort_by_direction_with_image_id(pos_list, f_direction):
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"""
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f_direction: h x w x 2
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pos_list: [[y, x], [y, x], [y, x] ...]
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"""
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def sort_part_with_direction(pos_list_full, point_direction):
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pos_list_full = np.array(pos_list_full).reshape(-1, 3)
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pos_list = pos_list_full[:, 1:]
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point_direction = np.array(point_direction).reshape(-1, 2)
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average_direction = np.mean(point_direction, axis=0, keepdims=True)
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pos_proj_leng = np.sum(pos_list * average_direction, axis=1)
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sorted_list = pos_list_full[np.argsort(pos_proj_leng)].tolist()
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|
sorted_direction = point_direction[np.argsort(pos_proj_leng)].tolist()
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|
return sorted_list, sorted_direction
|
|
|
|
pos_list = np.array(pos_list).reshape(-1, 3)
|
|
point_direction = f_direction[pos_list[:, 1], pos_list[:, 2]] # x, y
|
|
point_direction = point_direction[:, ::-1] # x, y -> y, x
|
|
sorted_point, sorted_direction = sort_part_with_direction(pos_list,
|
|
point_direction)
|
|
|
|
point_num = len(sorted_point)
|
|
if point_num >= 16:
|
|
middle_num = point_num // 2
|
|
first_part_point = sorted_point[:middle_num]
|
|
first_point_direction = sorted_direction[:middle_num]
|
|
sorted_fist_part_point, sorted_fist_part_direction = sort_part_with_direction(
|
|
first_part_point, first_point_direction)
|
|
|
|
last_part_point = sorted_point[middle_num:]
|
|
last_point_direction = sorted_direction[middle_num:]
|
|
sorted_last_part_point, sorted_last_part_direction = sort_part_with_direction(
|
|
last_part_point, last_point_direction)
|
|
sorted_point = sorted_fist_part_point + sorted_last_part_point
|
|
sorted_direction = sorted_fist_part_direction + sorted_last_part_direction
|
|
|
|
return sorted_point
|