Docling/docling/models/tesseract_ocr_cli_model.py
jimkarag02 9f8b479f17
fix(ocr): orig field in TesseractOcrCliModel as str (#1553)
fix: ensure orig and text are both strings in TesseractOcrCliModel

Signed-off-by: Dimitris Karagatslis <dimo9.dk@gmail.com>
2025-05-14 15:05:52 +02:00

281 lines
10 KiB
Python

import csv
import io
import logging
import os
import tempfile
from collections.abc import Iterable
from pathlib import Path
from subprocess import DEVNULL, PIPE, Popen
from typing import List, Optional, Tuple, Type
import pandas as pd
from docling_core.types.doc import BoundingBox, CoordOrigin
from docling_core.types.doc.page import BoundingRectangle, TextCell
from docling.datamodel.base_models import Page
from docling.datamodel.document import ConversionResult
from docling.datamodel.pipeline_options import (
AcceleratorOptions,
OcrOptions,
TesseractCliOcrOptions,
)
from docling.datamodel.settings import settings
from docling.models.base_ocr_model import BaseOcrModel
from docling.utils.ocr_utils import map_tesseract_script
from docling.utils.profiling import TimeRecorder
_log = logging.getLogger(__name__)
class TesseractOcrCliModel(BaseOcrModel):
def __init__(
self,
enabled: bool,
artifacts_path: Optional[Path],
options: TesseractCliOcrOptions,
accelerator_options: AcceleratorOptions,
):
super().__init__(
enabled=enabled,
artifacts_path=artifacts_path,
options=options,
accelerator_options=accelerator_options,
)
self.options: TesseractCliOcrOptions
self.scale = 3 # multiplier for 72 dpi == 216 dpi.
self._name: Optional[str] = None
self._version: Optional[str] = None
self._tesseract_languages: Optional[List[str]] = None
self._script_prefix: Optional[str] = None
if self.enabled:
try:
self._get_name_and_version()
self._set_languages_and_prefix()
except Exception as exc:
raise RuntimeError(
f"Tesseract is not available, aborting: {exc} "
"Install tesseract on your system and the tesseract binary is discoverable. "
"The actual command for Tesseract can be specified in `pipeline_options.ocr_options.tesseract_cmd='tesseract'`. "
"Alternatively, Docling has support for other OCR engines. See the documentation."
)
def _get_name_and_version(self) -> Tuple[str, str]:
if self._name is not None and self._version is not None:
return self._name, self._version # type: ignore
cmd = [self.options.tesseract_cmd, "--version"]
proc = Popen(cmd, stdout=PIPE, stderr=PIPE)
stdout, stderr = proc.communicate()
proc.wait()
# HACK: Windows versions of Tesseract output the version to stdout, Linux versions
# to stderr, so check both.
version_line = (
(stdout.decode("utf8").strip() or stderr.decode("utf8").strip())
.split("\n")[0]
.strip()
)
# If everything else fails...
if not version_line:
version_line = "tesseract XXX"
name, version = version_line.split(" ")
self._name = name
self._version = version
return name, version
def _run_tesseract(self, ifilename: str):
r"""
Run tesseract CLI
"""
cmd = [self.options.tesseract_cmd]
if "auto" in self.options.lang:
lang = self._detect_language(ifilename)
if lang is not None:
cmd.append("-l")
cmd.append(lang)
elif self.options.lang is not None and len(self.options.lang) > 0:
cmd.append("-l")
cmd.append("+".join(self.options.lang))
if self.options.path is not None:
cmd.append("--tessdata-dir")
cmd.append(self.options.path)
cmd += [ifilename, "stdout", "tsv"]
_log.info("command: {}".format(" ".join(cmd)))
proc = Popen(cmd, stdout=PIPE, stderr=DEVNULL)
output, _ = proc.communicate()
# _log.info(output)
# Decode the byte string to a regular string
decoded_data = output.decode("utf-8")
# _log.info(decoded_data)
# Read the TSV file generated by Tesseract
df_result = pd.read_csv(
io.StringIO(decoded_data), quoting=csv.QUOTE_NONE, sep="\t"
)
# Display the dataframe (optional)
# _log.info("df: ", df.head())
# Filter rows that contain actual text (ignore header or empty rows)
df_filtered = df_result[
df_result["text"].notna() & (df_result["text"].apply(str).str.strip() != "")
]
return df_filtered
def _detect_language(self, ifilename: str):
r"""
Run tesseract in PSM 0 mode to detect the language
"""
assert self._tesseract_languages is not None
cmd = [self.options.tesseract_cmd]
cmd.extend(["--psm", "0", "-l", "osd", ifilename, "stdout"])
_log.info("command: {}".format(" ".join(cmd)))
proc = Popen(cmd, stdout=PIPE, stderr=DEVNULL)
output, _ = proc.communicate()
decoded_data = output.decode("utf-8")
df_detected = pd.read_csv(
io.StringIO(decoded_data), sep=":", header=None, names=["key", "value"]
)
scripts = df_detected.loc[df_detected["key"] == "Script"].value.tolist()
if len(scripts) == 0:
_log.warning("Tesseract cannot detect the script of the page")
return None
script = map_tesseract_script(scripts[0].strip())
lang = f"{self._script_prefix}{script}"
# Check if the detected language has been installed
if lang not in self._tesseract_languages:
msg = f"Tesseract detected the script '{script}' and language '{lang}'."
msg += " However this language is not installed in your system and will be ignored."
_log.warning(msg)
return None
_log.debug(
f"Using tesseract model for the detected script '{script}' and language '{lang}'"
)
return lang
def _set_languages_and_prefix(self):
r"""
Read and set the languages installed in tesseract and decide the script prefix
"""
# Get all languages
cmd = [self.options.tesseract_cmd]
cmd.append("--list-langs")
_log.info("command: {}".format(" ".join(cmd)))
proc = Popen(cmd, stdout=PIPE, stderr=DEVNULL)
output, _ = proc.communicate()
decoded_data = output.decode("utf-8")
df_list = pd.read_csv(io.StringIO(decoded_data), header=None)
self._tesseract_languages = df_list[0].tolist()[1:]
# Decide the script prefix
if any(lang.startswith("script/") for lang in self._tesseract_languages):
script_prefix = "script/"
else:
script_prefix = ""
self._script_prefix = script_prefix
def __call__(
self, conv_res: ConversionResult, page_batch: Iterable[Page]
) -> Iterable[Page]:
if not self.enabled:
yield from page_batch
return
for page in page_batch:
assert page._backend is not None
if not page._backend.is_valid():
yield page
else:
with TimeRecorder(conv_res, "ocr"):
ocr_rects = self.get_ocr_rects(page)
all_ocr_cells = []
for ocr_rect in ocr_rects:
# Skip zero area boxes
if ocr_rect.area() == 0:
continue
high_res_image = page._backend.get_page_image(
scale=self.scale, cropbox=ocr_rect
)
try:
with tempfile.NamedTemporaryFile(
suffix=".png", mode="w+b", delete=False
) as image_file:
fname = image_file.name
high_res_image.save(image_file)
df_result = self._run_tesseract(fname)
finally:
if os.path.exists(fname):
os.remove(fname)
# _log.info(df_result)
# Print relevant columns (bounding box and text)
for ix, row in df_result.iterrows():
text = row["text"]
conf = row["conf"]
l = float(row["left"]) # noqa: E741
b = float(row["top"])
w = float(row["width"])
h = float(row["height"])
t = b + h
r = l + w
cell = TextCell(
index=ix,
text=str(text),
orig=str(text),
from_ocr=True,
confidence=conf / 100.0,
rect=BoundingRectangle.from_bounding_box(
BoundingBox.from_tuple(
coord=(
(l / self.scale) + ocr_rect.l,
(b / self.scale) + ocr_rect.t,
(r / self.scale) + ocr_rect.l,
(t / self.scale) + ocr_rect.t,
),
origin=CoordOrigin.TOPLEFT,
)
),
)
all_ocr_cells.append(cell)
# Post-process the cells
page.cells = self.post_process_cells(all_ocr_cells, page.cells)
# DEBUG code:
if settings.debug.visualize_ocr:
self.draw_ocr_rects_and_cells(conv_res, page, ocr_rects)
yield page
@classmethod
def get_options_type(cls) -> Type[OcrOptions]:
return TesseractCliOcrOptions