modules/latex2bbox_color.py

import os
import re
import json
import shutil
import logging
import subprocess
import numpy as np

from threading import Timer
from PIL import Image, ImageDraw
from modules.latex_processor import (
    normalize_latex,
    token_add_color_RGB,
    clean_latex
)
from modules.tokenize_latex.tokenize_latex import tokenize_latex


tabular_template = r"""
\documentclass[12pt]{article}
\usepackage[landscape]{geometry}
\usepackage{geometry}
\geometry{a<PaperSize>paper,scale=0.98}
\pagestyle{empty}
\usepackage{booktabs}
\usepackage{multirow}
\usepackage{amssymb}
\usepackage{upgreek}
\usepackage{amsmath}
\usepackage{xcolor}
\begin{document}
\makeatletter
\renewcommand*{\@textcolor}[3]{%%
  \protect\leavevmode
  \begingroup
    \color#1{#2}#3%%
  \endgroup
}
\makeatother
\begin{displaymath}
%s
\end{displaymath}
\end{document}
"""

formular_template = r"""
\documentclass[12pt]{article}
\usepackage[landscape]{geometry}
\usepackage{geometry}
\geometry{a<PaperSize>paper,scale=0.98}
\pagestyle{empty}
\usepackage{booktabs}
\usepackage{amsmath}
\usepackage{upgreek}
\usepackage{amssymb}
\usepackage{xcolor}
\begin{document}
\makeatletter
\renewcommand*{\@textcolor}[3]{%%
  \protect\leavevmode
  \begingroup
    \color#1{#2}#3%%
  \endgroup
}
\makeatother
\begin{displaymath}
%s
\end{displaymath}
\end{document}
"""


def run_cmd(cmd, timeout_sec=30):
    proc = subprocess.Popen(cmd, shell=True)
    kill_proc = lambda p: p.kill()
    timer = Timer(timeout_sec, kill_proc, [proc])
    try:
        timer.start()
        stdout,stderr = proc.communicate()
    finally:
        timer.cancel()
        
def convert_pdf2img(pdf_filename, png_filename):
    cmd = "magick -density 200 -quality 100 %s %s"%(pdf_filename, png_filename)
    os.system(cmd)

def crop_image(image_path, pad=8):
    img = Image.open(image_path).convert("L")
    img_data = np.asarray(img, dtype=np.uint8)
    nnz_inds = np.where(img_data!=255)
    if len(nnz_inds[0]) == 0:
        y_min = 0
        y_max = 10
        x_min = 0
        x_max = 10
    else:
        y_min = np.min(nnz_inds[0])
        y_max = np.max(nnz_inds[0])
        x_min = np.min(nnz_inds[1])
        x_max = np.max(nnz_inds[1])
        
    img = Image.open(image_path).convert("RGB").crop((x_min-pad, y_min-pad, x_max+pad, y_max+pad))
    img.save(image_path)
    
def extrac_bbox_from_color_image(image_path, color_list):
    img = Image.open(image_path).convert("RGB")
    W, H = img.size
    pixels = list(img.getdata())
    
    bbox_list = []
    for target_color in color_list:
        target_pixels = [ i for i, pixel in enumerate(pixels)if pixel == target_color ]
        x_list = []
        y_list = []
        for idx in target_pixels:
            x_list.append(idx % W)
            y_list.append(idx // W)
        try:
            y_min, y_max, x_min, x_max = min(y_list), max(y_list), min(x_list), max(x_list)
            bbox_list.append([x_min-1, y_min-1, x_max+1, y_max+1])

        except:
            bbox_list.append([])
            continue
        
    img = img.convert("L")
    img_bw = img.point(lambda x: 255 if x == 255 else 0, '1')
    img_bw.convert("RGB").save(image_path) 
    return bbox_list


def latex2bbox_color(input_arg):
    latex, basename, output_path, temp_dir, total_color_list = input_arg
    template = tabular_template if "tabular" in latex else formular_template
    output_bbox_path = os.path.join(output_path, 'bbox', basename+'.jsonl')
    output_vis_path = os.path.join(output_path, 'vis', basename+'.png')
    output_base_path = os.path.join(output_path, 'vis', basename+'_base.png')
    
    if os.path.exists(output_bbox_path) and os.path.exists(output_vis_path) and os.path.exists(output_base_path):
        return
    
    try:
        ret, new_latex = tokenize_latex(latex, middle_file=os.path.join(temp_dir, basename+'.txt'))
        if not(ret and new_latex):
            log = f"ERROR, Tokenize latex failed: {basename}."
            logging.info(log)
            new_latex = latex
        latex = normalize_latex(new_latex)
        token_list = []
        l_split = latex.strip().split(' ')
        color_list = total_color_list[0:len(l_split)]
        idx = 0
        while idx < len(l_split):
            l_split, idx, token_list = token_add_color_RGB(l_split, idx, token_list)

        rgb_latex = " ".join(l_split)
        for idx, color in enumerate(color_list):
            R, G, B = color
            rgb_latex = rgb_latex.replace(f"<color_{idx}>", f"{R},{G},{B}")

        if len(token_list) > 1300:
            paper_size = 3
        elif len(token_list) > 600:
            paper_size = 4
        else:
            paper_size = 5
        final_latex = formular_template.replace("<PaperSize>", str(paper_size)) % rgb_latex
        
    except Exception as e:
        log = f"ERROR, Preprocess latex failed: {basename}; {e}."
        logging.info(log)
        return
    
    pre_name = output_path.replace('/', '_').replace('.','_') + '_' + basename
    tex_filename = os.path.join(temp_dir, pre_name+'.tex')
    log_filename = os.path.join(temp_dir, pre_name+'.log')
    aux_filename = os.path.join(temp_dir, pre_name+'.aux')
    
    with open(tex_filename, "w") as w: 
        print(final_latex, file=w)
    run_cmd(f"pdflatex -interaction=nonstopmode -output-directory={temp_dir} {tex_filename} >/dev/null")
    try:
        os.remove(tex_filename)
        os.remove(log_filename)
        os.remove(aux_filename)
    except:
        pass
    pdf_filename = tex_filename[:-4]+'.pdf'
    if not os.path.exists(pdf_filename):
        log = f"ERROR, Compile pdf failed: {pdf_filename}"
        logging.info(log)
    else:
        convert_pdf2img(pdf_filename, output_base_path)
        os.remove(pdf_filename)
        
        crop_image(output_base_path)
        bbox_list = extrac_bbox_from_color_image(output_base_path, color_list)
        vis = Image.open(output_base_path)
        draw = ImageDraw.Draw(vis)

        with open(output_bbox_path, 'w') as f:
            for token, box in zip(token_list, bbox_list):
                item = {
                    "bbox": box,
                    "token": token
                }
                f.write(json.dumps(item)+'\n')

                if not box:
                    continue
                x_min, y_min, x_max, y_max = box
                draw.rectangle([x_min, y_min, x_max, y_max], fill=None, outline=(0,250,0), width=1)
                draw.text((x_min, y_min), token, (250,0,0))
            
        vis.save(output_vis_path)