web demo加入了katex支持, 不再需要本地安装xelatex渲染器

requirements.txt

@@ -9,5 +9,4 @@ tensorboardX
 nltk
 python-multipart
 
-pdf2image
 augraphy

src/web.py

@@ -2,14 +2,11 @@ import os
 import io
 import base64
 import tempfile
-import time
-import subprocess
 import shutil
 import streamlit as st
+import re
 
-from PIL import Image, ImageChops
+from PIL import Image
-from pathlib import Path
-from pdf2image import convert_from_path
 from models.ocr_model.utils.inference import inference
 from models.ocr_model.model.TexTeller import TexTeller
 
@@ -69,6 +66,19 @@ def get_model():
 def get_tokenizer():
     return TexTeller.get_tokenizer(os.environ['TOKENIZER_DIR'])
 
+def to_katex(formula: str) -> str:
+    res = formula
+    res = re.sub(r'\\mbox\{([^}]*)\}', r'\1', res)
+    res = re.sub(r'boldmath\$(.*?)\$', r'bm{\1}', res)
+    res = re.sub(r'\\\[(.*?)\\\]', r'\1\\newline', res) 
+
+    pattern = r'(\\(?:left|middle|right|big|Big|bigg|Bigg|bigl|Bigl|biggl|Biggl|bigm|Bigm|biggm|Biggm|bigr|Bigr|biggr|Biggr))\{([^}]*)\}'
+    replacement = r'\1\2'
+    res = re.sub(pattern, replacement, res)
+    if res.endswith(r'\newline'):
+        res = res[:-8]
+    return res
+
 def get_image_base64(img_file):
     buffered = io.BytesIO()
     img_file.seek(0)
@@ -76,55 +86,12 @@ def get_image_base64(img_file):
     img.save(buffered, format="PNG")
     return base64.b64encode(buffered.getvalue()).decode()
 
-def rendering(formula: str, out_img_path: Path) -> bool:
-    build_dir = out_img_path / 'build'
-    build_dir.mkdir(exist_ok=True, parents=True)
-    f = build_dir / 'formula.tex'
-    f.touch(exist_ok=True)
-    f.write_text(tex.format(formula=formula))
-
-    p = subprocess.Popen([
-        'xelatex', 
-        f'-output-directory={build_dir}', 
-        '-interaction=nonstopmode',
-        '-halt-on-error',
-        f'{f}'
-    ])
-    p.communicate()
-    return p.returncode == 0
-
-def pdf_to_pngbytes(pdf_path):
-    images = convert_from_path(pdf_path, dpi=400,first_page=1, last_page=1)
-    trimmed_images = trim(images[0])
-    png_image_bytes = io.BytesIO()
-    trimmed_images.save(png_image_bytes, format='PNG')
-    png_image_bytes.seek(0)
-    return png_image_bytes
-
-def trim(im):
-    bg = Image.new(im.mode, im.size, im.getpixel((0,0)))
-    diff = ImageChops.difference(im, bg)
-    diff = ImageChops.add(diff, diff, 2.0, -100)
-    bbox = diff.getbbox()
-    if bbox:
-        return im.crop(bbox)
-    return im
-
-
 model = get_model()
 tokenizer = get_tokenizer()
-# check if xelatex is installed
-xelatex_installed = os.system('which xelatex > /dev/null 2>&1') == 0
 
 if "start" not in st.session_state:
     st.session_state["start"] = 1
-
-    if xelatex_installed:
     st.toast('Hooray!', icon='🎉')
-        time.sleep(0.5)
-        st.toast("Xelatex have been detected.", icon='✅')
-    else: 
-        st.error('xelatex is not installed. Please install it before using TexTeller.')
 
 
 #  ============================     pages      =============================== #
@@ -133,11 +100,6 @@ st.markdown(html_string, unsafe_allow_html=True)
 
 uploaded_file = st.file_uploader("",type=['jpg', 'png', 'pdf'])
 
-if xelatex_installed:
-    st.caption('🥳 Xelatex have been detected, rendered image will be displayed in the web page.')
-else:
-    st.caption('😭 Xelatex is not detected, please check the resulting latex code by yourself, or check ... to have your xelatex setup ready.')
-
 if uploaded_file:
     img = Image.open(uploaded_file)
 
@@ -170,60 +132,18 @@ if uploaded_file:
 
     with st.spinner("Predicting..."):
         uploaded_file.seek(0)
-        TeXTeller_result = inference(
+        TexTeller_result = inference(
             model,
             tokenizer,
             [png_file_path],
             True if os.environ['USE_CUDA'] == 'True' else False,
             int(os.environ['NUM_BEAM'])
         )[0]
-        if not xelatex_installed:
+        st.success('Completed!', icon="✅")
-            st.markdown(fail_gif_html, unsafe_allow_html=True)
-            st.warning('Unable to find xelatex to render image. Please check the prediction results yourself.', icon="🤡")
-            txt = st.text_area(
-                ":red[Predicted formula]",
-                TeXTeller_result,
-                height=150,
-            )
-        else:
-            is_successed = rendering(TeXTeller_result, Path(temp_dir))
-            if is_successed:
-                # st.code(TeXTeller_result, language='latex')
-
-                img_base64 = get_image_base64(pdf_to_pngbytes(Path(temp_dir) / 'build' / 'formula.pdf'))
         st.markdown(suc_gif_html, unsafe_allow_html=True)
-                st.success('Successfully rendered!', icon="✅")
+        katex_res = to_katex(TexTeller_result)
-                txt = st.text_area(
+        st.text_area(":red[Predicted formula]", katex_res, height=150)
-                    ":red[Predicted formula]",
+        st.latex(katex_res)
-                    TeXTeller_result,
-                    height=150,
-                )
-                # st.latex(TeXTeller_result)
-                st.markdown(f"""
-                    <style>
-                    .centered-container {{
-                        text-align: center;
-                    }}
-                    .centered-image {{
-                        display: block;
-                        margin-left: auto;
-                        margin-right: auto;
-                        max-width: 500px;
-                        max-height: 500px;
-                    }}
-                    </style>
-                    <div class="centered-container">
-                        <img src="data:image/png;base64,{img_base64}" class="centered-image" alt="Input image">
-                    </div>
-                    """, unsafe_allow_html=True)
-            else:
-                st.markdown(fail_gif_html, unsafe_allow_html=True)
-                st.error('Rendering failed. You can try using a higher resolution image or splitting the multi line formula into a single line for better results.', icon="❌")
-                txt = st.text_area(
-                    ":red[Predicted formula]",
-                    TeXTeller_result,
-                    height=150,
-                )
 
         shutil.rmtree(temp_dir)