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If you want to analyse images in order to extract data from image and pdf files, you can use Tesseract with Tika.

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To install Tesseract, the steps are very easy :
To install it on a Debian/Ubuntu system, run the following command:

sudo apt-get install tesseract-ocr

Congrats ! Tesseract is now installed and ready to be used. However by default, Tesseract is only able to deal with english language, if you want to deal with other languages you will need to install the corresponding package (if available). The pattern of a language paclage is: tesseract-ocr-[country_code]

The country code is based on three letters. For example the Tesseract package for the french language is: tesseract-ocr-fra
So to install the french package you will need to run the following command:

sudo apt-get install tesseract-ocr-fra

You can find the list of available language packages for Tesseract on the web or here: https://packages.ubuntu.com/search?keywords=tesseract-ocr
You can also install all the available languages in a single command:

sudo apt-get install tesseract-ocr-all

With this configuration, you can already extract data from your images !  

For that, just configure your jobs in MCF as usual and use the Tika included in Solr so you ned to choose the DatafariSolr output and NOT choose TikaEmbedded transformation connector.

And that's it, start the job and the OCRization will  be activated.

Remarks :

1. If you want to extract data from PDF, you need to do an additional step ie customize the file PDFParser.properties which is included in the tika-parsers.jar.
   Install Vim : 

   Code Block
   apt-get install vim

   Stop datafari :

   Code Block
   cd /opt/datafari/bin bash stop-datafari.sh

   Edit the jar :

   Code Block
   vim /opt/datafari/solr/solrcloud/FileShare/lib/extraction/tika-parsers*.jar

   Choose the file org/apache/tika/parser/pdf/PDFParser.properties and change the line ocrStrategy :

   Code Block
   ocrStrategy ocr_and_text_extraction

   Save your changes 
   Start Datafari :

   Code Block
   cd /opt/datafari/bin bash start-datafari.sh

   
   And as before, just start your jobs in MCF, the data extraction will be done for PDF content.

2. Customize the Tesseract configuration
   By default, Tesseract does the text extraction for English content. If you want to add other languages you need to edit the Tesseract configuration file located here : org/apache/tika/parser/ocr/TesseractOCRConfig.properties
   Install Vim : 

   Code Block
   apt-get install vim

   Stop datafari :

   Code Block
   cd /opt/datafari/bin bash stop-datafari.sh

   Edit the jar :

   Code Block
   vim /opt/datafari/solr/solrcloud/FileShare/lib/extraction/tika-parsers*.jar

   Choose the file org/apache/tika/parser/ocr/TesseractOCRConfig.properties and change the line language, if I want to add French language, the configuration will be :

   Code Block
   language=eng+fra

   Save your changes 
   Start Datafari :

   Code Block
   cd /opt/datafari/bin bash start-datafari.sh

   And as before, just start your jobs in MCF, the data extraction will be done for PDF content.