#!/usr/bin/env python2.7
# coding=utf-8
"""
ocr_pyflow.py
Usage: For usage instructions run with option --help
Author: Patrick Jentsch
"""
import argparse
import multiprocessing
import os
import sys
from pyflow import WorkflowRunner
''' TODO:
' Implement --end-page: Last page to ocr
' Implement --memMb: Total amount of memory (RAM) available for this workflow. Default: 2048 * nCores
' Implement --rotate: Rotate pages from input (90, 180, 270)
' Implement --split-pages: Split pages in half after possible rotation
' Implement --start-page: First page to ocr
'''
def parse_arguments():
parser = argparse.ArgumentParser("Performs OCR of (historical) documents utilizing OCRopus for preprocessing and Tesseract OCR \
for OCR. Available outputs are HOCR, PDF, shrinked PDF, and simple DTAbf \
(TEI P5 compliant). Software requirements: imagemagick, ocropus, pdftk, pdftoppm, poppler-utils, pyflow, python2.7, tesseract")
parser.add_argument("-i",
dest="inputDir",
help="Input directory.",
required=True)
parser.add_argument("-l",
dest='lang',
help="Language for OCR",
required=True)
parser.add_argument("-o",
dest="outputDir",
help="Output directory.",
required=True)
parser.add_argument("--keep-intermediates",
action='store_true',
default=False,
dest="keepIntermediates",
help="Keep intermediate files.",
required=False)
parser.add_argument("--nCores",
default=multiprocessing.cpu_count(),
dest="nCores",
help="Total number of cores available.",
required=False,
type=int)
return parser.parse_args()
class OCRWorkflow(WorkflowRunner):
def __init__(self, jobs, keepIntermediates, lang, nCores):
self.jobs = jobs
self.keepIntermediates = keepIntermediates
self.lang = lang
self.nCores = nCores
def workflow(self):
###
# Task "mkdir_job": create output directories
# Dependencies: None
###
mkdir_jobs = []
mkdir_job_number = 0
for job in self.jobs:
mkdir_job_number += 1
cmd = 'mkdir -p "%s" "%s" "%s" "%s"' % (
os.path.join(job["output_dir"], "hocr_files"),
os.path.join(job["output_dir"], "tmp", "ocropus-nlbin"),
os.path.join(job["output_dir"], "tmp", "tesseract"),
os.path.join(job["output_dir"], "tmp", "tiff_files")
)
mkdir_jobs.append(self.addTask(label="mkdir_job_-_%i" % (mkdir_job_number), command=cmd))
###
# Task "split_job": split input file into one tiff file per page
# Dependencies: mkdir_jobs
###
split_jobs = []
split_job_number = 0
for job in self.jobs:
split_job_number += 1
if job["basename"].endswith(".tif") or job["basename"].endswith(".tiff"):
# TODO: Make the following command work
'''
cmd = 'convert "%s" "%s"' % (
job["path"],
os.path.join(job["output_dir"], "tmp", "tiff_files", os.path.basename(job["path"]).rsplit(".", 1)[0] + "-%sd.tif" % ("%")))
'''
# WORKAROUND
cmd = 'tiff2pdf -o "%s" "%s" && pdftoppm "%s" "%s" -tiff -r 300 -tiffcompression lzw -cropbox && rm "%s"' % (
os.path.join(job["output_dir"], "tmp", "tiff_files", job["basename"].rsplit(".", 1)[0] + ".pdf"),
job["path"],
os.path.join(job["output_dir"], "tmp", "tiff_files", job["basename"].rsplit(".", 1)[0] + ".pdf"),
os.path.join(job["output_dir"], "tmp", "tiff_files", job["basename"].rsplit(".", 1)[0]),
os.path.join(job["output_dir"], "tmp", "tiff_files", job["basename"].rsplit(".", 1)[0] + ".pdf")
)
else:
cmd = 'pdftoppm "%s" "%s" -tiff -r 300 -tiffcompression lzw -cropbox' % (
job["path"],
os.path.join(job["output_dir"], "tmp", "tiff_files", "page")
)
split_jobs.append(self.addTask(label="split_job_-_%i" % (split_job_number), command=cmd, dependencies=mkdir_jobs))
###
# Task "ocropus_nlbin_job": binarize tiff files from previous split
# Dependencies: split_jobs
###
ocropusnlbin_jobs = []
ocropusnlbin_job_number = 0
for job in self.jobs:
ocropusnlbin_job_number += 1
cmd = 'ocropus-nlbin -o "%s" "%s"/*' % (
os.path.join(job["output_dir"], "tmp", "ocropus-nlbin"),
os.path.join(job["output_dir"], "tmp", "tiff_files")
)
ocropusnlbin_jobs.append(self.addTask(label="ocropusnlbin_job_-_%i" % (ocropusnlbin_job_number), command=cmd, dependencies=split_jobs))
###
# Task "tesseract_job": perform OCR on binarized images
# Dependencies: ocropusnlbin_jobs
###
self.waitForTasks()
tesseract_jobs = []
tesseract_job_number = 0
for job in self.jobs:
# This list is empty if you don't wait for ocropus_nlbin_jobs to complete
for file in filter(lambda x: x.endswith(".bin.png"), os.listdir(os.path.join(job["output_dir"], "tmp", "ocropus-nlbin"))):
tesseract_job_number += 1
cmd = 'tesseract "%s" "%s" -l "%s" hocr pdf txt' % (
os.path.join(job["output_dir"], "tmp", "ocropus-nlbin", file),
os.path.join(job["output_dir"], "tmp", "tesseract", file.rsplit(".", 2)[0]),
self.lang
)
tesseract_jobs.append(self.addTask(label="tesseract_job_-_%i" % (tesseract_job_number), command=cmd, dependencies=ocropusnlbin_jobs, nCores=min(4, self.nCores)))
###
# Task "hocr_to_teip5_job": create TEI P5 file from hocr files
# Dependencies: tesseract_jobs
###
hocr_to_teip5_jobs = []
hocr_to_teip5_job_number = 0
for job in self.jobs:
hocr_to_teip5_job_number += 1
cmd = 'parse_hocr "%s" "%s"' % (
os.path.join(job["output_dir"], "tmp", "tesseract"),
os.path.join(job["output_dir"], job["basename"].rsplit(".", 1)[0] + ".xml")
)
hocr_to_teip5_jobs.append(self.addTask(label="hocr_to_teip5_job_-_%i" % (hocr_to_teip5_job_number), command=cmd, dependencies=tesseract_jobs))
###
# Task "move_hocr_job": move hocr files from /tmp/tesseract to /hocr_files
# Dependencies: hocr_to_teip5_jobs
###
move_hocr_jobs = []
move_hocr_job_number = 0
for job in self.jobs:
move_hocr_job_number += 1
cmd = 'mv "%s"/*.hocr "%s"' % (
os.path.join(job["output_dir"], "tmp", "tesseract"),
os.path.join(job["output_dir"], "hocr_files")
)
move_hocr_jobs.append(self.addTask(label="move_hocr_job_-_%i" % (move_hocr_job_number), command=cmd, dependencies=hocr_to_teip5_jobs))
###
# Task "pdf_merge_job": Merge PDF files
# Dependencies: tesseract_jobs
###
pdf_merge_jobs = []
pdf_merge_job_number = 0
for job in self.jobs:
pdf_merge_job_number += 1
cmd = 'pdftk "%s"/*.pdf cat output "%s"' % (
os.path.join(job["output_dir"], "tmp", "tesseract"),
os.path.join(job["output_dir"], job["basename"].rsplit(".", 1)[0] + ".pdf")
)
pdf_merge_jobs.append(self.addTask(label="pdf_merge_job_-_%i" % (pdf_merge_job_number), command=cmd, dependencies=tesseract_jobs))
###
# Task "pdf_to_txt_job":
# Dependencies: pdf_merge_jobs
###
pdf_to_txt_jobs = []
pdf_to_txt_job_number = 0
for job in self.jobs:
pdf_to_txt_job_number += 1
cmd = 'pdftotext -raw "%s"' % (
os.path.join(job["output_dir"], job["basename"].rsplit(".", 1)[0] + ".pdf")
)
pdf_merge_jobs.append(self.addTask(label="pdf_to_txt_job_-_%i" % (pdf_to_txt_job_number), command=cmd, dependencies=pdf_merge_jobs))
###
# Task "cleanup_job": remove temporary files
# Dependencies: hocr_to_teip5_jobs + move_hocr_jobs + pdf_merge_jobs + pdf_to_txt_jobs
###
cleanup_jobs = []
cleanup_job_counter = 0
if not self.keepIntermediates:
for job in self.jobs:
cleanup_job_counter += 1
cmd = 'rm -r "%s"' % (
os.path.join(job["output_dir"], "tmp")
)
cleanup_jobs.append(self.addTask(label="cleanup_job_-_%i" % (cleanup_job_counter), command=cmd, dependencies=hocr_to_teip5_jobs + move_hocr_jobs + pdf_merge_jobs + pdf_to_txt_jobs))
def analyze_jobs(inputDir, outputDir, level=1):
jobs = []
if level > 2:
return jobs
for file in os.listdir(inputDir):
if os.path.isdir(os.path.join(inputDir, file)):
jobs += analyze_jobs(
os.path.join(inputDir, file),
os.path.join(outputDir, file),
level + 1
)
elif file.endswith(".pdf") or file.endswith(".tif") or file.endswith(".tiff"):
jobs.append({"basename": os.path.basename(file), "output_dir": os.path.join(outputDir, file.rsplit(".", 1)[0]), "path": os.path.join(inputDir, file)})
return jobs
def main():
args = parse_arguments()
wflow = OCRWorkflow(
analyze_jobs(args.inputDir, args.outputDir),
args.keepIntermediates,
args.lang,
args.nCores
)
retval = wflow.run(nCores=args.nCores)
sys.exit(retval)
if __name__ == "__main__":
main()