from sklearn.cluster import DBSCAN import numpy as np from loguru import logger from magic_pdf.libs.boxbase import _is_in_or_part_overlap from magic_pdf.libs.ocr_content_type import ContentType LINE_STOP_FLAG = ['.', '!', '?', '。', '！', '？',"：", ":", ")", "）", ";"] INLINE_EQUATION = ContentType.InlineEquation INTERLINE_EQUATION = ContentType.InterlineEquation TEXT = "text" def __get_span_text(span): c = span.get('content', '') if len(c)==0: c = span.get('image_path', '') return c def __add_line_period(blocks, layout_bboxes): """ 为每行添加句号 如果这个行 1. 以行内公式结尾，但没有任何标点符号,此时加个句号，认为他就是段落结尾。 """ for block in blocks: for line in block['lines']: last_span = line['spans'][-1] span_type = last_span['type'] if span_type in [INLINE_EQUATION]: span_content = last_span['content'].strip() if span_type==INLINE_EQUATION and span_content[-1] not in LINE_STOP_FLAG: if span_type in [INLINE_EQUATION, INTERLINE_EQUATION]: last_span['content'] = span_content + '.' def __valign_lines(blocks, layout_bboxes): """ 在一个layoutbox内对齐行的左侧和右侧。 扫描行的左侧和右侧，如果x0, x1差距不超过一个阈值，就强行对齐到所处layout的左右两侧（和layout有一段距离）。 3是个经验值，TODO，计算得来，可以设置为1.5个正文字符。 """ min_distance = 3 min_sample = 2 new_layout_bboxes = [] for layout_box in layout_bboxes: blocks_in_layoutbox = [b for b in blocks if _is_in_or_part_overlap(b['bbox'], layout_box['layout_bbox'])] if len(blocks_in_layoutbox)==0: continue x0_lst = np.array([[line['bbox'][0], 0] for block in blocks_in_layoutbox for line in block['lines']]) x1_lst = np.array([[line['bbox'][2], 0] for block in blocks_in_layoutbox for line in block['lines']]) x0_clusters = DBSCAN(eps=min_distance, min_samples=min_sample).fit(x0_lst) x1_clusters = DBSCAN(eps=min_distance, min_samples=min_sample).fit(x1_lst) x0_uniq_label = np.unique(x0_clusters.labels_) x1_uniq_label = np.unique(x1_clusters.labels_) x0_2_new_val = {} # 存储旧值对应的新值映射 x1_2_new_val = {} for label in x0_uniq_label: if label==-1: continue x0_index_of_label = np.where(x0_clusters.labels_==label) x0_raw_val = x0_lst[x0_index_of_label][:,0] x0_new_val = np.min(x0_lst[x0_index_of_label][:,0]) x0_2_new_val.update({idx: x0_new_val for idx in x0_raw_val}) for label in x1_uniq_label: if label==-1: continue x1_index_of_label = np.where(x1_clusters.labels_==label) x1_raw_val = x1_lst[x1_index_of_label][:,0] x1_new_val = np.max(x1_lst[x1_index_of_label][:,0]) x1_2_new_val.update({idx: x1_new_val for idx in x1_raw_val}) for block in blocks_in_layoutbox: for line in block['lines']: x0, x1 = line['bbox'][0], line['bbox'][2] if x0 in x0_2_new_val: line['bbox'][0] = int(x0_2_new_val[x0]) if x1 in x1_2_new_val: line['bbox'][2] = int(x1_2_new_val[x1]) # 其余对不齐的保持不动 # 由于修改了block里的line长度，现在需要重新计算block的bbox for block in blocks_in_layoutbox: block['bbox'] = [min([line['bbox'][0] for line in block['lines']]), min([line['bbox'][1] for line in block['lines']]), max([line['bbox'][2] for line in block['lines']]), max([line['bbox'][3] for line in block['lines']])] """新计算layout的bbox，因为block的bbox变了。""" layout_x0 = min([block['bbox'][0] for block in blocks_in_layoutbox]) layout_y0 = min([block['bbox'][1] for block in blocks_in_layoutbox]) layout_x1 = max([block['bbox'][2] for block in blocks_in_layoutbox]) layout_y1 = max([block['bbox'][3] for block in blocks_in_layoutbox]) new_layout_bboxes.append([layout_x0, layout_y0, layout_x1, layout_y1]) return new_layout_bboxes def __common_pre_proc(blocks, layout_bboxes): """ 不分语言的，对文本进行预处理 """ #__add_line_period(blocks, layout_bboxes) aligned_layout_bboxes = __valign_lines(blocks, layout_bboxes) return aligned_layout_bboxes def __pre_proc_zh_blocks(blocks, layout_bboxes): """ 对中文文本进行分段预处理 """ pass def __pre_proc_en_blocks(blocks, layout_bboxes): """ 对英文文本进行分段预处理 """ pass def __group_line_by_layout(blocks, layout_bboxes, lang="en"): """ 每个layout内的行进行聚合 """ # 因为只是一个block一行目前, 一个block就是一个段落 lines_group = [] for lyout in layout_bboxes: lines = [line for block in blocks if _is_in_or_part_overlap(block['bbox'], lyout['layout_bbox']) for line in block['lines']] lines_group.append(lines) return lines_group def __split_para_in_layoutbox(lines_group, new_layout_bbox, lang="en", char_avg_len=10): """ lines_group 进行行分段——layout内部进行分段。lines_group内每个元素是一个Layoutbox内的所有行。 1. 先计算每个group的左右边界。 2. 然后根据行末尾特征进行分段。 末尾特征：以句号等结束符结尾。并且距离右侧边界有一定距离。 且下一行开头不留空白。 """ paras = [] right_tail_distance = 1.5 * char_avg_len for lines in lines_group: total_lines = len(lines) if total_lines<=1: # 0行无需处理。1行无法分段。 continue #layout_right = max([line['bbox'][2] for line in lines]) layout_right = __find_layout_bbox_by_line(lines[0]['bbox'], new_layout_bbox)[2] layout_left = __find_layout_bbox_by_line(lines[0]['bbox'], new_layout_bbox)[0] para = [] # 元素是line for i, line in enumerate(lines): # 如果i有下一行，那么就要根据下一行位置综合判断是否要分段。如果i之后没有行，那么只需要判断一下行结尾特征。 cur_line_type = line['spans'][-1]['type'] #cur_line_last_char = line['spans'][-1]['content'][-1] next_line = lines[i+1] if i= layout_right - right_tail_distance and next_line and next_line['bbox'][0] == layout_left: # 现在这行到了行尾沾满，下一行存在且顶格。 para.append(line) else: para.append(line) paras.append(para) para = [] else: # 其他，图片、表格、行间公式，各自占一段 if len(para)>0: # 先把之前的段落加入到结果中 paras.append(para) para = [] paras.append([line]) # 再把当前行加入到结果中。当前行为行间公式、图、表等。 para = [] if len(para)>0: paras.append(para) para = [] return paras def __find_layout_bbox_by_line(line_bbox, layout_bboxes): """ 根据line找到所在的layout """ for layout in layout_bboxes: if _is_in_or_part_overlap(line_bbox, layout): return layout return None def __connect_para_inter_layoutbox(layout_paras, new_layout_bbox, lang="en"): """ layout之间进行分段。 主要是计算前一个layOut的最后一行和后一个layout的第一行是否可以连接。 连接的条件需要同时满足： 1. 上一个layout的最后一行沾满整个行。并且没有结尾符号。 2. 下一行开头不留空白。 """ connected_layout_paras = [] for i, para in enumerate(layout_paras): if i==0: connected_layout_paras.append(para) continue pre_last_line = layout_paras[i-1][-1] next_first_line = layout_paras[i][0] pre_last_line_text = ''.join([__get_span_text(span) for span in pre_last_line['spans']]) pre_last_line_type = pre_last_line['spans'][-1]['type'] next_first_line_text = ''.join([__get_span_text(span) for span in next_first_line['spans']]) next_first_line_type = next_first_line['spans'][0]['type'] if pre_last_line_type not in [TEXT, INLINE_EQUATION] or next_first_line_type not in [TEXT, INLINE_EQUATION]: # TODO，真的要做好，要考虑跨table, image, 行间的情况 connected_layout_paras.append(para) continue pre_x2_max = __find_layout_bbox_by_line(pre_last_line['bbox'], new_layout_bbox)[2] next_x0_min = __find_layout_bbox_by_line(next_first_line['bbox'], new_layout_bbox)[0] pre_last_line_text = pre_last_line_text.strip() next_first_line_text = next_first_line_text.strip() if pre_last_line['bbox'][2] == pre_x2_max and pre_last_line_text[-1] not in LINE_STOP_FLAG and next_first_line['bbox'][0]==next_x0_min: # 前面一行沾满了整个行，并且没有结尾符号.下一行没有空白开头。 """连接段落条件成立，将前一个layout的段落和后一个layout的段落连接。""" connected_layout_paras[-1].extend(para) else: """连接段落条件不成立，将前一个layout的段落加入到结果中。""" connected_layout_paras.append(para) return connected_layout_paras def __connect_para_inter_page(pre_page_paras, next_page_paras, pre_page_layout_bbox, next_page_layout_bbox, lang): """ 连接起来相邻两个页面的段落——前一个页面最后一个段落和后一个页面的第一个段落。 是否可以连接的条件： 1. 前一个页面的最后一个段落最后一行沾满整个行。并且没有结尾符号。 2. 后一个页面的第一个段落第一行没有空白开头。 """ pre_last_para = pre_page_paras[-1] next_first_para = next_page_paras[0] pre_last_line = pre_last_para[-1] next_first_line = next_first_para[0] pre_last_line_text = ''.join([__get_span_text(span) for span in pre_last_line['spans']]) pre_last_line_type = pre_last_line['spans'][-1]['type'] next_first_line_text = ''.join([__get_span_text(span) for span in next_first_line['spans']]) next_first_line_type = next_first_line['spans'][0]['type'] if pre_last_line_type not in [TEXT, INLINE_EQUATION] or next_first_line_type not in [TEXT, INLINE_EQUATION]: # TODO，真的要做好，要考虑跨table, image, 行间的情况 # 不是文本，不连接 return False pre_x2_max = __find_layout_bbox_by_line(pre_last_line['bbox'], pre_page_layout_bbox)[2] next_x0_min = __find_layout_bbox_by_line(next_first_line['bbox'], next_page_layout_bbox)[0] pre_last_line_text = pre_last_line_text.strip() next_first_line_text = next_first_line_text.strip() if pre_last_line['bbox'][2] == pre_x2_max and pre_last_line_text[-1] not in LINE_STOP_FLAG and next_first_line['bbox'][0]==next_x0_min: # 前面一行沾满了整个行，并且没有结尾符号.下一行没有空白开头。 """连接段落条件成立，将前一个layout的段落和后一个layout的段落连接。""" pre_page_paras[-1].extend(next_first_para) next_page_paras.pop(0) # 删除后一个页面的第一个段落， 因为他已经被合并到前一个页面的最后一个段落了。 return True else: return False def __do_split(blocks, layout_bboxes, new_layout_bbox, lang="en"): """ 根据line和layout情况进行分段 先实现一个根据行末尾特征分段的简单方法。 """ """ 算法思路： 1. 扫描layout里每一行，找出来行尾距离layout有边界有一定距离的行。 2. 从上述行中找到末尾是句号等可作为断行标志的行。 3. 参照上述行尾特征进行分段。 4. 图、表，目前独占一行，不考虑分段。 """ lines_group = __group_line_by_layout(blocks, layout_bboxes, lang) # block内分段 layout_paras = __split_para_in_layoutbox(lines_group, new_layout_bbox, lang) # layout内分段 connected_layout_paras = __connect_para_inter_layoutbox(layout_paras, new_layout_bbox, lang) # layout间链接段落 return connected_layout_paras def para_split(pdf_info_dict, lang="en"): """ 根据line和layout情况进行分段 """ new_layout_of_pages = [] # 数组的数组，每个元素是一个页面的layoutS for _, page in pdf_info_dict.items(): blocks = page['preproc_blocks'] layout_bboxes = page['layout_bboxes'] new_layout_bbox = __common_pre_proc(blocks, layout_bboxes) new_layout_of_pages.append(new_layout_bbox) splited_blocks = __do_split(blocks, layout_bboxes, new_layout_bbox, lang) page['para_blocks'] = splited_blocks """连接页面与页面之间的可能合并的段落""" pdf_infos = list(pdf_info_dict.values()) for i, page in enumerate(pdf_info_dict.values()): if i==0: continue pre_page_paras = pdf_infos[i-1]['para_blocks'] next_page_paras = pdf_infos[i]['para_blocks'] pre_page_layout_bbox = new_layout_of_pages[i-1] next_page_layout_bbox = new_layout_of_pages[i] is_conn= __connect_para_inter_page(pre_page_paras, next_page_paras, pre_page_layout_bbox, next_page_layout_bbox, lang) if is_conn: logger.info(f"连接了第{i-1}页和第{i}页的段落")