Snippets registered in Google Colaboratory (PDF text conversion)

PDF text conversion

pdfminer

command

!pip install pdfminer.six
!python /usr/local/bin/pdf2txt.py -o data.txt data.pdf

Python

from pdfminer.high_level import extract_text

text = extract_text("data.pdf")

pdfbox

command

#URL changes with the latest version
!wget https://www-eu.apache.org/dist/pdfbox/2.0.21/pdfbox-app-2.0.21.jar -O pdfbox-app.jar

#Text conversion
!java -jar pdfbox-app.jar ExtractText -sort -encoding UTF-8 data.pdf

#image
!java -jar pdfbox-app.jar PDFToImage -imageType png -dpi 300 data.pdf

Python

!pip install python-pdfbox

import pdfbox

p = pdfbox.PDFBox()
p.extract_text("data.pdf", sort=True)

poppler

command

!apt install poppler-utils poppler-data

#Text conversion
!pdftotext -layout data.pdf

!pdfinfo data.pdf

#repair
!pdftocairo -pdf data.pdf data_repaired.pdf

PDF table conversion

tabula

command

!wget https://github.com/tabulapdf/tabula-java/releases/download/v1.0.4/tabula-1.0.4-jar-with-dependencies.jar -O tabula.jar

# lattice
!java -jar tabula.jar -o data.csv -p all -l data.pdf

# stream
!java -jar tabula.jar -o data.csv -p all -t data.pdf

Python

!pip install tabula-py

import pandas as pd
from tabula import read_pdf

dfs = read_pdf("data.pdf", pages="all", lattice=True)

dfs = read_pdf("data.pdf", pages="all", lattice=True, pandas_options={"header": None})

Camelot

command

!apt install python3-tk ghostscript
!pip install camelot-py[cv]

# !pip install camelot-py[plot]

# !camelot --help

!camelot -p all -o data.csv -f csv lattice data.pdf

!camelot -p all -o data.csv -f csv -strip ' .\n' -split lattice -scale 40 data.pdf

Python

import camelot

tables = camelot.read_pdf("data.pdf", pages="all", split_text=True, strip_text=" \n", line_scale=40)

pdfplumber

!pip install pdfplumber
!apt install libmagickwand-dev ghostscript

#PDF can be converted to images/etc/ImageMagick-6/policy.Overwrite xml
%%writefile /etc/ImageMagick-6/policy.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE policymap>

<policymap>

  <policy domain="resource" name="memory" value="256MiB"/>
  <policy domain="resource" name="map" value="512MiB"/>
  <policy domain="resource" name="width" value="16KP"/>
  <policy domain="resource" name="height" value="16KP"/>
  <policy domain="resource" name="area" value="128MB"/>
  <policy domain="resource" name="disk" value="1GiB"/>

  <policy domain="delegate" rights="none" pattern="URL"/>
  <policy domain="delegate" rights="none" pattern="HTTPS"/>
  <policy domain="delegate" rights="none" pattern="HTTP"/>

  <policy domain="path" rights="none" pattern="@*"/>
  <policy domain="cache" name="shared-secret" value="passphrase" stealth="true"/>

  <policy domain="coder" rights="none" pattern="PS"/>
  <policy domain="coder" rights="none" pattern="PS2"/>
  <policy domain="coder" rights="none" pattern="PS3"/>
  <policy domain="coder" rights="none" pattern="EPS"/>
  <policy domain="coder" rights="read|write" pattern="PDF" />
  <policy domain="coder" rights="none" pattern="XPS"/>
</policymap>

!pdfplumber < data.pdf > data.csv

import pdfplumber
import pandas as pd

pdf = pdfplumber.open("data.pdf")

page = pdf.pages[0]

page.find_tables()[0]

#Confirm the position of characters
page.chars

#Get text with crop
crop = page.within_bbox((0, 90, p0.width, 105))

s = crop.extract_text()
s

#PDF confirmation
im = page.to_image()
im

table_settings = {

    #Vertical reference
    "vertical_strategy": "lines",
    #Specify the vertical delimiter numerically (list)
    "explicit_vertical_lines": [],

    #Horizontal reference
    "horizontal_strategy": "lines",
    #Specify the horizontal division numerically (list)
    "explicit_horizontal_lines": [],

    #If it is within the allowable range, adjust to the same horizontal position or vertical position * Adjust above?
    "snap_tolerance": 3,

    #If within tolerance, join
    "join_tolerance": 3,

    #Shorter edges than destroyed before attempting to rebuild the table?
    "edge_min_length": 3,

    #Minimum character height
    "min_words_vertical": 3,

    #Minimum character height
    "min_words_horizontal": 1,

    #Recognize whitespace as part of a word and do not use it as a delimiter
    "keep_blank_chars": False,

    #Recognized as a word if the character spacing is as follows
    "text_tolerance": 3,
    "text_x_tolerance": None,
    "text_y_tolerance": None,
    
    #Tolerance if the left and right edges of the text do not exactly match the vertical lines?
    "intersection_tolerance": 3,
    "intersection_x_tolerance": None,
    "intersection_y_tolerance": None,
}

#Character confirmation
im.reset().draw_rects(page.extract_words())

#Check the table
im.reset().debug_tablefinder()

with pdfplumber.open("data.pdf") as pdf:

    dfs = []

    for page in pdf.pages:

        table = page.extract_table(table_settings)

        df_tmp = pd.DataFrame(table[1:], columns=table[0])

        dfs.append(df_tmp)

df = pd.concat(dfs)

OCR

tesseract-ocr

!add-apt-repository ppa:alex-p/tesseract-ocr -y
!apt update
!apt install tesseract-ocr
!apt install libtesseract-dev
!tesseract -v

!apt install tesseract-ocr-jpn  tesseract-ocr-jpn-vert
!apt install tesseract-ocr-script-jpan tesseract-ocr-script-jpan-vert
!tesseract --list-langs
!pip install pytesseract

try:
    from PIL import Image
except ImportError:
    import Image
    
import pytesseract

import cv2
import numpy as np

from google.colab.patches import cv2_imshow

img = cv2.imread("test.jpg ")

#Black and white inversion
img_gray, _ = cv2.decolor(img)

cv2_imshow(img_gray)