thiagoalessio/tesseract_ocr

A wrapper to work with Tesseract OCR inside PHP.

1.0.0-RC 2016-04-20 23:29 UTC

README

Tesseract OCR for PHP logo: A baby elephant sucking letters from a book

A wrapper to work with Tesseract OCR inside PHP.

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Installation

First of all, make sure you have Tesseract OCR installed. (v3.03 or greater)

As a composer dependency

{
    "require": {
        "thiagoalessio/tesseract_ocr": "1.0.0-RC"
    }
}

Usage

Basic usage

Given the following image (text.jpeg):

The quick brown fox jumps over the lazy dog

And the following code:

<?php
echo (new TesseractOCR('text.png'))
    ->run();

The output would be:

The quick brown fox
jumps over the lazy
dog.

Other languages

Given the following image (german.jpeg):

grüßen - Google Translate said it means "to greet" in German

And the following code:

<?php
echo (new TesseractOCR('german.png'))
    ->run();

The output would be:

griifien

Which is not good, but defining a language:

<?php
echo (new TesseractOCR('german.png'))
    ->lang('deu')
    ->run();

Will produce:

grüßen

Multiple languages

Given the following image (multi-languages.jpeg):

The phrase "I each apple sushi", with mixed English, Japanese and Portuguese

And the following code ....

<?php
echo (new TesseractOCR('multi-languages.png'))
    ->lang('eng', 'jpn', 'por')
    ->run();

The output would be:

I eat 寿司 de maçã

Inducing recognition

Given the following image (8055.png):

Number 8055

And the following code ....

<?php
echo (new TesseractOCR('8055.png'))
    ->whitelist(range('A', 'Z'))
    ->run();

The output would be:

BOSS

API

->executable('/path/to/tesseract')

Define a custom location of the tesseract executable, if by any reason it is not present in the $PATH.

->tessdataDir('/path')

Specify a custom location for the tessdata directory.

->userWords('/path/to/user-words.txt')

Specify the location of user words file.

This is a plain text file containing a list of words that you want to be considered as a normal dictionary words by tesseract.

Useful when dealing with contents that contain technical terminology, jargon, etc.

Example of a user words file:

$ cat /path/to/user-words.txt
foo
bar

->userPatterns('/path/to/user-patterns.txt')

Specify the location of user patterns file.

If the contents you are dealing with have known patterns, this option can help a lot tesseract's recognition accuracy.

Example of a user patterns file:

$ cat /path/to/user-patterns.txt'
1-\d\d\d-GOOG-441
www.\n\\\*.com

->lang('lang1', 'lang2', 'lang3')

Define one or more languages to be used during the recognition. A complete list of available languages can be found at https://github.com/tesseract-ocr/tesseract/blob/master/doc/tesseract.1.asc#languages

Tip from @daijiale: Use the combination ->lang('chi_sim', 'chi_tra') for proper recognition of Chinese.

->psm(6)

Specify the Page Segmentation Mode, which instructs tesseract how to interpret the given image.

Possible psm values are:

 0 = Orientation and script detection (OSD) only.
 1 = Automatic page segmentation with OSD.
 2 = Automatic page segmentation, but no OSD, or OCR.
 3 = Fully automatic page segmentation, but no OSD. (Default)
 4 = Assume a single column of text of variable sizes.
 5 = Assume a single uniform block of vertically aligned text.
 6 = Assume a single uniform block of text.
 7 = Treat the image as a single text line.
 8 = Treat the image as a single word.
 9 = Treat the image as a single word in a circle.
10 = Treat the image as a single character.

->config('configvar', 'value')

Tesseract offers incredible control to the user through its 660 configuration vars.

You can see the complete list by running the following command:

$ tesseract --print-parameters
Tesseract parameters:
... long list with all parameters ...

->whitelist(range('a', 'z'), range(0, 9), '-_@')

This is a shortcut for ->config('tessedit_char_whitelist', 'abcdef....').

Where to get help

  • #tesseract-ocr-for-php on freenode IRC

License

Apache License 2.0.