172 lines
4.4 KiB
Python

import glob
import os
import random
import re
import shutil
import subprocess
import time
import pyocr
from PIL import Image
from django.conf import settings
from django.core.management.base import BaseCommand
from documents.models import Document
class Command(BaseCommand):
"""
Loop over every file found in CONSUMPTION_DIR and:
1. Convert it to a greyscale tif
2. Convert it to a full-colour jpg
3. Use tesseract on the tif
4. Store the OCR'd text in the database along with the paths to the jpg
and original pdf
5. Delete the pdf and images
"""
CONVERT = settings.CONVERT_BINARY
SCRATCH = settings.SCRATCH_DIR
CONSUME = settings.CONSUMPTION_DIR
OCR = pyocr.get_available_tools()[0]
MEDIA_IMG = os.path.join(settings.MEDIA_ROOT, "documents", "img")
MEDIA_PDF = os.path.join(settings.MEDIA_ROOT, "documents", "pdf")
PARSER_REGEX = re.compile(r"^.*/(.*) - (.*)\.pdf$")
def __init__(self, *args, **kwargs):
self.verbosity = 0
self.stats = {}
BaseCommand.__init__(self, *args, **kwargs)
def handle(self, *args, **options):
self.verbosity = options["verbosity"]
self._setup()
try:
while True:
self.loop()
time.sleep(10)
print(".")
except KeyboardInterrupt:
print("Exiting")
def loop(self):
for pdf in os.listdir(self.CONSUME):
pdf = os.path.join(self.CONSUME, pdf)
if not os.path.isfile(pdf):
continue
if not pdf.endswith(".pdf"):
continue
if self._is_ready(pdf):
continue
if self.verbosity > 1:
print("Consuming {}".format(pdf))
pngs = self._get_greyscale(pdf)
jpgs = self._get_colour(pdf)
text = self._get_ocr(pngs)
self._store(text, jpgs, pdf)
self._cleanup(pngs, jpgs)
def _setup(self):
for d in (self.SCRATCH, self.MEDIA_IMG, self.MEDIA_PDF):
try:
os.makedirs(d)
except FileExistsError:
pass
def _is_ready(self, pdf):
"""
Detect whether `pdf` is ready to consume or if it's still being written
to by the scanner.
"""
t = os.stat(pdf).st_mtime
if self.stats.get(pdf) == t:
del(self.stats[pdf])
return True
self.stats[pdf] = t
return False
def _get_greyscale(self, pdf):
i = random.randint(1000000, 4999999)
png = os.path.join(self.SCRATCH, "{}.png".format(i))
subprocess.Popen((
self.CONVERT, "-density", "300", "-depth", "8",
"-type", "grayscale", pdf, png
)).wait()
return sorted(glob.glob(os.path.join(self.SCRATCH, "{}*".format(i))))
def _get_colour(self, pdf):
i = random.randint(5000000, 9999999)
jpg = os.path.join(self.SCRATCH, "{}.jpg".format(i))
subprocess.Popen((self.CONVERT, pdf, jpg)).wait()
return sorted(glob.glob(os.path.join(self.SCRATCH, "{}*".format(i))))
def _get_ocr(self, pngs):
r = ""
for png in pngs:
with Image.open(os.path.join(self.SCRATCH, png)) as f:
r += self.OCR.image_to_string(f)
r += "\n\n\n\n\n\n\n\n"
return r
def _store(self, text, jpgs, pdf):
sender, title = self._parse_file_name(pdf)
doc = Document.objects.create(sender=sender, title=title, content=text)
shutil.move(jpgs[0], os.path.join(
self.MEDIA_IMG, "{:07}.jpg".format(doc.pk)))
shutil.move(pdf, os.path.join(
self.MEDIA_PDF, "{:07}.pdf".format(doc.pk)))
def _parse_file_name(self, pdf):
"""
We use a crude naming convention to make handling the sender and title
easier:
"sender - title.pdf"
"""
m = re.match(self.PARSER_REGEX, pdf)
if m:
return m.group(1), m.group(2)
return "", ""
def _cleanup(self, pngs, jpgs):
jpg_glob = os.path.join(
self.SCRATCH, re.sub(r"^.*/(\d+)-\d+.jpg$", "\\1*", jpgs[0]))
png_glob = os.path.join(
self.SCRATCH, re.sub(r"^.*/(\d+)-\d+.png$", "\\1*", pngs[0]))
for f in list(glob.glob(jpg_glob)) + list(glob.glob(png_glob)):
os.unlink(f)