MinerU/magic_pdf/pre_proc/ocr_detect_all_bboxes.py

from magic_pdf.libs.boxbase import get_minbox_if_overlap_by_ratio, calculate_overlap_area_in_bbox1_area_ratio, \
    calculate_iou
from magic_pdf.libs.drop_tag import DropTag
from magic_pdf.libs.ocr_content_type import BlockType


def ocr_prepare_bboxes_for_layout_split(img_blocks, table_blocks, discarded_blocks, text_blocks,
                                        title_blocks, interline_equation_blocks, page_w, page_h):
    all_bboxes = []
    for image in img_blocks:
        x0, y0, x1, y1 = image['bbox']
        all_bboxes.append([x0, y0, x1, y1, None, None, None, BlockType.Image, None, None, None, None])

    for table in table_blocks:
        x0, y0, x1, y1 = table['bbox']
        all_bboxes.append([x0, y0, x1, y1, None, None, None, BlockType.Table, None, None, None, None])

    for text in text_blocks:
        x0, y0, x1, y1 = text['bbox']
        all_bboxes.append([x0, y0, x1, y1, None, None, None, BlockType.Text, None, None, None, None])

    for title in title_blocks:
        x0, y0, x1, y1 = title['bbox']
        all_bboxes.append([x0, y0, x1, y1, None, None, None, BlockType.Title, None, None, None, None])

    for interline_equation in interline_equation_blocks:
        x0, y0, x1, y1 = interline_equation['bbox']
        all_bboxes.append([x0, y0, x1, y1, None, None, None, BlockType.InterlineEquation, None, None, None, None])

    '''block嵌套问题解决'''
    '''文本框与标题框重叠，优先信任标题框'''
    all_bboxes = fix_text_overlap_title_blocks(all_bboxes)
    '''任何框体与舍弃框重叠，优先信任舍弃框'''
    all_bboxes = remove_need_drop_blocks(all_bboxes, discarded_blocks)
    '''经过以上处理后，还存在大框套小框的情况，则删除小框'''
    all_bboxes = remove_overlaps_min_blocks(all_bboxes)

    '''discarded_blocks中只保留宽度超过1/3页面宽度的，高度超过10的，处于页面下半50%区域的（限定footnote）'''
    for discarded in discarded_blocks:
        x0, y0, x1, y1 = discarded['bbox']
        if (x1 - x0) > (page_w / 3) and (y1 - y0) > 10 and y0 > (page_h / 2):
            all_bboxes.append([x0, y0, x1, y1, None, None, None, BlockType.Footnote, None, None, None, None])

    return all_bboxes


def fix_text_overlap_title_blocks(all_bboxes):
    # 先提取所有text和title block
    text_blocks = []
    for block in all_bboxes:
        if block[7] == BlockType.Text:
            text_blocks.append(block)
    title_blocks = []
    for block in all_bboxes:
        if block[7] == BlockType.Title:
            title_blocks.append(block)

    for text_block in text_blocks:
        for title_block in title_blocks:
            text_block_bbox = text_block[0], text_block[1], text_block[2], text_block[3]
            title_block_bbox = title_block[0], title_block[1], title_block[2], title_block[3]
            if calculate_iou(text_block_bbox, title_block_bbox) > 0.8:
                all_bboxes.remove(text_block)

    return all_bboxes


def remove_need_drop_blocks(all_bboxes, discarded_blocks):
    for block in all_bboxes.copy():
        for discarded_block in discarded_blocks:
            block_bbox = block[0], block[1], block[2], block[3]
            if calculate_overlap_area_in_bbox1_area_ratio(block_bbox, discarded_block['bbox']) > 0.6:
                all_bboxes.remove(block)
    return all_bboxes


def remove_overlaps_min_blocks(all_bboxes):
    #  删除重叠blocks中较小的那些
    for block1 in all_bboxes.copy():
        for block2 in all_bboxes.copy():
            if block1 != block2:
                block1_bbox = [block1[0], block1[1], block1[2], block1[3]]
                block2_bbox = [block2[0], block2[1], block2[2], block2[3]]
                overlap_box = get_minbox_if_overlap_by_ratio(block1_bbox, block2_bbox, 0.8)
                if overlap_box is not None:
                    bbox_to_remove = next(
                        (block for block in all_bboxes if [block[0], block[1], block[2], block[3]] == overlap_box),
                        None)
                    if bbox_to_remove is not None:
                        all_bboxes.remove(bbox_to_remove)

    return all_bboxes