resolve_bbox_conflict.py

"""
从pdf里提取出来api给出的bbox,然后根据重叠情况做出取舍
1. 首先去掉出现在图片上的bbox，图片包括表格和图片
2. 然后去掉出现在文字blcok上的图片bbox
"""

from magic_pdf.libs.boxbase import _is_in, _is_in_or_part_overlap, _is_left_overlap
from magic_pdf.libs.drop_tag import ON_IMAGE_TEXT, ON_TABLE_TEXT


def resolve_bbox_overlap_conflict(images:list, tables:list, interline_equations:list, inline_equations:list, text_raw_blocks:list):
    """
    text_raw_blocks结构是从pymupdf里直接取到的结构，具体样例参考test/assets/papre/pymu_textblocks.json
    当下采用一种粗暴的方式：
    1. 去掉图片上的公式
    2. 去掉table上的公式
    2. 图片和文字block部分重叠，首先丢弃图片
    3. 图片和图片重叠，修改图片的bbox，使得图片不重叠(暂时没这么做，先把图片都扔掉)
    4. 去掉文字bbox里位于图片、表格上的文字（一定要完全在图、表内部）
    5. 去掉表格上的文字
    """
    text_block_removed = []
    images_backup = []

    # 去掉位于图片上的文字block
    for image_box in images:
        for text_block in text_raw_blocks:
            text_bbox = text_block["bbox"]
            if _is_in(text_bbox, image_box):
                text_block['tag'] = ON_IMAGE_TEXT
                text_block_removed.append(text_block)
    # 去掉table上的文字block
    for table_box in tables:
        for text_block in text_raw_blocks:
            text_bbox = text_block["bbox"]
            if _is_in(text_bbox, table_box):
                text_block['tag'] = ON_TABLE_TEXT
                text_block_removed.append(text_block)
                
    for text_block in text_block_removed:
        if text_block in text_raw_blocks:
            text_raw_blocks.remove(text_block)
    
    # 第一步去掉在图片上出现的公式box
    temp = []
    for image_box in images:
        for eq1 in interline_equations:
            if _is_in_or_part_overlap(image_box, eq1[:4]):
                temp.append(eq1)
        for eq2 in inline_equations:
            if _is_in_or_part_overlap(image_box, eq2[:4]):
                temp.append(eq2)
                
    for eq in temp:
        if eq in interline_equations:
            interline_equations.remove(eq)
        if eq in inline_equations:
            inline_equations.remove(eq)
                
    # 第二步去掉在表格上出现的公式box
    temp = []
    for table_box in tables:
        for eq1 in interline_equations:
            if _is_in_or_part_overlap(table_box, eq1[:4]):
                temp.append(eq1)
        for eq2 in inline_equations:
            if _is_in_or_part_overlap(table_box, eq2[:4]):
                temp.append(eq2)
                
    for eq in temp:
        if eq in interline_equations:
            interline_equations.remove(eq)
        if eq in inline_equations:
            inline_equations.remove(eq)
                
    # 图片和文字重叠，丢掉图片
    for image_box in images:
        for text_block in text_raw_blocks:
            text_bbox = text_block["bbox"]
            if _is_in_or_part_overlap(image_box, text_bbox):
                images_backup.append(image_box)
                break
    for image_box in images_backup:
        images.remove(image_box)
                
    # 图片和图片重叠，两张都暂时不参与版面计算
    images_dup_index = []
    for i in range(len(images)):
        for j in range(i+1, len(images)):
            if _is_in_or_part_overlap(images[i], images[j]):
                images_dup_index.append(i)
                images_dup_index.append(j)
    
    dup_idx = set(images_dup_index)
    for img_id in dup_idx:
        images_backup.append(images[img_id])
        images[img_id] = None
        
    images = [img for img in images if img is not None]
    
    # 如果行间公式和文字block重叠，放到临时的数据里，防止这些文字box影响到layout计算。通过计算IOU合并行间公式和文字block
    # 对于这样的文本块删除，然后保留行间公式的大小不变。
    # 当计算完毕layout，这部分再合并回来
    text_block_removed_2 = []
    # for text_block in text_raw_blocks:
    #     text_bbox = text_block["bbox"]
    #     for eq in interline_equations:
    #         ratio = calculate_overlap_area_2_minbox_area_ratio(text_bbox, eq[:4])
    #         if ratio>0.05:
    #             text_block['tag'] = "belong-to-interline-equation"
    #             text_block_removed_2.append(text_block)
    #             break
            
    # for tb in text_block_removed_2:
    #     if tb in text_raw_blocks:
    #         text_raw_blocks.remove(tb)
                
    # text_block_removed = text_block_removed + text_block_removed_2
    
    return images, tables, interline_equations, inline_equations, text_raw_blocks, text_block_removed, images_backup, text_block_removed_2


def check_text_block_horizontal_overlap(text_blocks:list, header, footer) -> bool:
    """
    检查文本block之间的水平重叠情况，这种情况如果发生，那么这个pdf就不再继续处理了。
    因为这种情况大概率发生了公式没有被检测出来。
    
    """
    if len(text_blocks)==0:
        return False
    
    page_min_y = 0
    page_max_y = max(yy['bbox'][3] for yy in text_blocks)
    
    def __max_y(lst:list):
        if len(lst)>0:
            return max([item[1] for item in lst])
        return page_min_y
    
    def __min_y(lst:list):
        if len(lst)>0:
            return min([item[3] for item in lst])
        return page_max_y
    
    clip_y0 = __max_y(header)
    clip_y1 = __min_y(footer)
    
    txt_bboxes = []
    for text_block in text_blocks:
        bbox = text_block["bbox"]
        if bbox[1]>=clip_y0 and bbox[3]<=clip_y1:
            txt_bboxes.append(bbox)
    
    for i in range(len(txt_bboxes)):
        for j in range(i+1, len(txt_bboxes)):
            if _is_left_overlap(txt_bboxes[i], txt_bboxes[j]) or _is_left_overlap(txt_bboxes[j], txt_bboxes[i]):
                return True
            
    return False