Convert from pdf to txt 2 [pyocr]
Introduction
Last time, I used pdfminer to convert from pdf to txt. However, it didn't work because of the problem of the target pdf. This time we will work on solving the problem with pyocr.
Previous article https://qiita.com/ptxyasu/items/4180035bd0ccd789c858
Purpose
Extract text from pdf.
What was used
This time, I thought about extracting the text using pyocr. However, pyocr also converted from pdf to image using pdf2image to extract text from the image.
[pyocr] https://gitlab.gnome.org/World/OpenPaperwork/pyocr [pdf2image]https://github.com/Belval/pdf2image
The introduction of tesseract and pyocr was done by referring to the following articles. https://qiita.com/nabechi6011/items/3a367ca94dbd208efcc7 https://github.com/tesseract-ocr/tesseract/wiki
Process flow
- Please input pdf name followed by target pdf file name
- Convert pdf file to image
- Create a result directory to output the results
- Extract text from image with pyocr
- Output the result to the txt file in result
Is. The program is shown at the end of the article.
result
Input: object1.pdf
output
object1.txt
8 CLASSES AND OBJECT-ORIENTED PROGRAMMING
We now turn our attention to our last major topic related to writing programs in
Python: using classes to organize programs around modules and data
abstractions.
Classes can be used in many different ways. In this book we emphasize using
them in the context of object-oriented programming. The key to object-
oriented programming is thinking about objects as collections of both data and
the methods that operate on that data.
The ideas underlying object-oriented programming are about forty years old, and
have been widely accepted and practiced over the last twenty years or so, In the
mid-1970s people began to write articles explaining the benefits of this approach
to programming. About the same time, the programming languages SmallTalk
(at Xerox PARC) and CLU (at MIT) provided linguistic support for the ideas. But
it wasn’t until the arrival of C++ and Java that it really took off in practice.
We have been implicitly relying on object-oriented programming throughout
most of this book. Back in Section 2.1.1 we said “Objects are the core things
that Python programs manipulate. Every object has a type that defines the
kinds of things that programs can do with objects of that type.” Since Chapter
5, we have relied heavily upon built-in types such as list and dict and the
methods associated with those types. But just as the designers of a
programming language can build in only a small fraction of the useful functions,
they can only build in only a small fraction of the useful types. We have already
looked at a mechanism that allows programmers to define new functions; we
now look at a mechanism that allows programmers to define new types.
8.1
Abstract Data Types and Classes
The notion of an abstract data type is quite simple. An abstract data type is a
set of objects and the operations on those objects. These are bound together so
that one can pass an object from one part of a program to another, and in doing
so provide access not only to the data attributes of the object but also to
operations that make it easy to manipulate that data.
The specifications of those operations define an interface between the abstract
data type and the rest of the program. The interface defines the behavior of the
operations—what they do, but not how they do it. The interface thus provides
an abstraction barrier that isolates the rest of the program from the data
structures, algorithms, and code involved in providing a realization of the type
abstraction.
Programming is about managing complexity in a way that facilitates change.
There are two powerful mechanisms available for accomplishing this:
decomposition and abstraction. Decomposition creates structure in a program,
and abstraction suppresses detail. The key is to suppress the appropriate
In the 10th line, years or so, In the, became., But other than that, it was correct. Well, it's perfect.
What I couldn't do with the previous pdfminer can be done by using pyocr (tesseract)!
Since it was made with the input image this time, I think that text can be extracted from the pdf created by scanning the printed matter. Also this time, I plan to paste this extracted text into google translate, Next time, I want to use googletrans to programmatically change it to Japanese.
program
The program has been published on github https://github.com/ptxyasu/pdf2text
The following pdf2text_pyocr.py is executed. Change the input pdf file to image by convert_from_path. Then pass the images to pyocr_read one by one.
pdf2text_pyocr.py
from pdf2image import convert_from_path
from pyocr_read import pyocr_read
path = input("Please input pdf name\n")
images = convert_from_path(path)
i = 0
path,e = path.split(".")
pdf2read = pyocr_read(path)
for image in images:
pdf2read.oneshot_read(image)
i += 1
The following pyocr_read.py is called from the above pdf2text_pyocr. Init () determines the pyocr tool and creates a directory to store the results. It also determines the language to recognize. The languages displayed in "Available languages" can be selected. For example, eng for English and jpn for Japanese Then, extract the text from the image received from pdf2text_pyocr with pyocr and write the output to a file.
pyocr_read.py
import pyocr
import pyocr.builders
import os
class pyocr_read(object):
def __init__(self,path):
self.path = path
tools = pyocr.get_available_tools()
if len(tools) == 0:
print("No OCR tool found")
sys.exit(1)
self.tool = tools[0]
langs = self.tool.get_available_languages()
print("Available languages: %s" % ", ".join(langs))
self.lang = input("Please input language you want to recognize : ")
if os.path.exists("./result") != True:
os.mkdir("./result")
return
def oneshot_read(self,img):
txt = self.tool.image_to_string(img, lang=self.lang, builder=pyocr.builders.TextBuilder())
print(txt)
file = open("./result/"+ self.path + ".txt",mode = "a",encoding = "utf-8")
file.write(txt+"\n")
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