> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abbyy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Data Extraction

> Extract all data — printed and handwritten text, tables, barcodes, checkmarks, images — from a document with ABBYY FineReader Engine and save it as structured JSON.

This scenario is used to extract all possible data from a document and store it in a structured way.

The result is a JSON file which represents the document structure. It stores all document objects: printed and handwritten text, tables, barcodes, checkmarks, and images with their location and attributes. This format is optimal for further processing, storing data in a database, or integrating with another application.

A document goes through several processing steps in this scenario:

1. Preprocessing of scanned images or photos

   Images you get by means of a scanner or a digital camera may need some tweaking before they can be optically recognized. For example, noisy images or images with distorted text lines will need some correction for optical recognition to be successful.

2. Extracting all the data on the document in a structured way

   During layout analysis, various objects are detected on the image and put into blocks of corresponding type. The blocks are recognized according to the optimal settings of their type. In the course of synthesis, the logical structure of the document is restored in a consistent manner. The text order even for complex layouts is preserved to be similar to how a human would read it. This ensures that re-recognition of the same document would result in the same order of the text.

3. Export to a structured format

   The recognized document is saved to JSON or XML.

## Scenario implementation

<Note>
  The code samples provided in this topic are Windows -specific.
</Note>

Below you will find a detailed description of the recommended method of using ABBYY FineReader Engine 12 to extract the data from documents. The proposed method uses the processing settings that are most suitable for this purpose.

<Accordion title="Step 1. Loading ABBYY FineReader Engine">
  To start your work with ABBYY FineReader Engine, you need to create the [Engine](/fine-reader/engine/api-reference/engine-object-iengine-interface) object. The Engine object is the top object in the hierarchy of the ABBYY FineReader Engine objects and provides various global settings, some processing methods, and methods for creating the other objects.

  To create the Engine object, you can use the [InitializeEngine](/fine-reader/engine/api-reference/functions/initializeengine-function) function. See also [other ways to load Engine object](/fine-reader/engine/guided-tour/advanced-techniques/programming-aspects/different-ways-to-load-engine) (Win).

  ### C\#

  ```csharp theme={null}
  public class EngineLoader : IDisposable
  {
      public EngineLoader()
      {
          // Initialize these variables with the full path to FREngine.dll, your Customer Project ID,
          // and, if applicable, the path to your Online License token file and the Online License password
          string enginePath = "";
          string customerProjectId = "";
          string licensePath = "";
          string licensePassword = "";
          // Load the FREngine.dll library
          dllHandle = LoadLibraryEx(enginePath, IntPtr.Zero, LOAD_WITH_ALTERED_SEARCH_PATH);
             
          try
          {
              if (dllHandle == IntPtr.Zero)
              {
                  throw new Exception("Can't load " + enginePath);
              }
              IntPtr initializeEnginePtr = GetProcAddress(dllHandle, "InitializeEngine");
              if (initializeEnginePtr == IntPtr.Zero)
              {
                  throw new Exception("Can't find InitializeEngine function");
              }
              IntPtr deinitializeEnginePtr = GetProcAddress(dllHandle, "DeinitializeEngine");
              if (deinitializeEnginePtr == IntPtr.Zero)
              {
                  throw new Exception("Can't find DeinitializeEngine function");
              }
              IntPtr dllCanUnloadNowPtr = GetProcAddress(dllHandle, "DllCanUnloadNow");
              if (dllCanUnloadNowPtr == IntPtr.Zero)
              {
                  throw new Exception("Can't find DllCanUnloadNow function");
              }
              // Convert pointers to delegates
              initializeEngine = (InitializeEngine)Marshal.GetDelegateForFunctionPointer(
                  initializeEnginePtr, typeof(InitializeEngine));
              deinitializeEngine = (DeinitializeEngine)Marshal.GetDelegateForFunctionPointer(
                  deinitializeEnginePtr, typeof(DeinitializeEngine));
              dllCanUnloadNow = (DllCanUnloadNow)Marshal.GetDelegateForFunctionPointer(
                  dllCanUnloadNowPtr, typeof(DllCanUnloadNow));
              // Call the InitializeEngine function 
              // passing the path to the Online License file and the Online License password
              int hresult = initializeEngine(customerProjectId, licensePath, licensePassword, 
                  "", "", false, ref engine);
              Marshal.ThrowExceptionForHR(hresult);
          }
          catch (Exception)
          {
              // Free the FREngine.dll library
              engine = null;
              // Deleting all objects before FreeLibrary call
              GC.Collect();
              GC.WaitForPendingFinalizers();
              GC.Collect();
              FreeLibrary(dllHandle);
              dllHandle = IntPtr.Zero;
              initializeEngine = null;
              deinitializeEngine = null;
              dllCanUnloadNow = null;
              throw;
          }
      }
      // Kernel32.dll functions
      [DllImport("kernel32.dll")]
      private static extern IntPtr LoadLibraryEx(string dllToLoad, IntPtr reserved, uint flags);
      private const uint LOAD_WITH_ALTERED_SEARCH_PATH = 0x00000008;
      [DllImport("kernel32.dll")]
      private static extern IntPtr GetProcAddress(IntPtr hModule, string procedureName);
      [DllImport("kernel32.dll")]
      private static extern bool FreeLibrary(IntPtr hModule);
      // FREngine.dll functions
      [UnmanagedFunctionPointer(CallingConvention.StdCall, CharSet = CharSet.Unicode)]
      private delegate int InitializeEngine(string customerProjectId, string licensePath, 
          string licensePassword, string tempFolder, string dataFolder, bool isSharedCPUCoresMode, 
          ref FREngine.IEngine engine);
      [UnmanagedFunctionPointer(CallingConvention.StdCall)]
      private delegate int DeinitializeEngine();
      [UnmanagedFunctionPointer(CallingConvention.StdCall)]
      private delegate int DllCanUnloadNow();
      // private variables
      private FREngine.IEngine engine = null;
      // Handle to FREngine.dll
      private IntPtr dllHandle = IntPtr.Zero;
      private InitializeEngine initializeEngine = null;
      private DeinitializeEngine deinitializeEngine = null;
      private DllCanUnloadNow dllCanUnloadNow = null;
  }
  ```

  ### C++ (COM)

  ```cpp theme={null}
  // Initialize these variables with the path to FREngine.dll, your FineReader Engine customer project ID,
  // and, if applicable, the path to the Online License token and Online License password
  wchar_t* FreDllPath;
  wchar_t* CustomerProjectId;
  wchar_t* LicensePath;  // if you don't use an Online License, assign empty strings to these variables
  wchar_t* LicensePassword;
  // HANDLE to FREngine.dll
  static HMODULE libraryHandle = 0;
  // Global FineReader Engine object
  FREngine::IEnginePtr Engine;
  void LoadFREngine()
  {
      if( Engine != 0 ) {
      // Already loaded
      return;
      }
      // First step: load FREngine.dll
      if( libraryHandle == 0 ) {
          libraryHandle = LoadLibraryEx( FreDllPath, 0, LOAD_WITH_ALTERED_SEARCH_PATH );
          if( libraryHandle == 0 ) {
              throw L"Error while loading ABBYY FineReader Engine";
          }
      }
      // Second step: obtain the Engine object
      typedef HRESULT ( STDAPICALLTYPE* InitializeEngineFunc )( BSTR, BSTR, BSTR, BSTR, 
          BSTR, VARIANT_BOOL, FREngine::IEngine** );
      InitializeEngineFunc pInitializeEngine =
      ( InitializeEngineFunc )GetProcAddress( libraryHandle, "InitializeEngine" );
      if( pInitializeEngine == 0 || pInitializeEngine( CustomerProjectId, LicensePath, 
          LicensePassword, L"", L"", VARIANT_FALSE, &Engine ) != S_OK ) {
      UnloadFREngine();
      throw L"Error while loading ABBYY FineReader Engine";
      }
  }
  ```
</Accordion>

<Accordion title="Step 2. Loading settings for the scenario">
  ABBYY FineReader Engine enables loading of all processing settings that are most suitable for this scenario using the [LoadPredefinedProfile](/fine-reader/engine/api-reference/engine-object-iengine-interface/supplementary-methods/loadpredefinedprofile-method) method of the [Engine](/fine-reader/engine/api-reference/engine-object-iengine-interface) object. This method receives the profile name as an input parameter. Please see [Working with Profiles](/fine-reader/engine/guided-tour/advanced-techniques/working-with-profiles) for more information.

  The settings for this scenario are available in the [DataExtraction](/fine-reader/engine/guided-tour/advanced-techniques/working-with-profiles#dataextraction) predefined profile:

  * Layout analysis and recognition prioritize accuracy over speed.
  * Detects all text on an image, including handwritten text and small text areas of low quality.
  * Detects tables, checkmarks, and barcodes.
  * Full synthesis of the logical structure of a document is performed.

  ### C\#

  ```csharp theme={null}
  // Load a predefined profile
  engine.LoadPredefinedProfile("DataExtraction");
  ```

  ### C++ (COM)

  ```cpp theme={null}
  // Load a predefined profile
  Engine->LoadPredefinedProfile( L"DataExtraction" );
  ```

  If you wish to change processing settings, use the corresponding parameter objects. Please see [Additional optimization](/fine-reader/engine/guided-tour/basic-usage-scenarios-implementation/data-extraction#optimization) section below for more information.
</Accordion>

<Accordion title="Step 3. Loading and preprocessing the images">
  ABBYY FineReader Engine provides the [FRDocument](/fine-reader/engine/api-reference/document-related-objects/frdocument) object which allows processing multi-page documents. Using of this object allows you to preserve the logical organization of the document, retaining the original text and columns, fonts, styles, etc.

  To load images of a single document and preprocess them, you should create the FRDocument object and add images to it. You may do one of the following:

  * Create the FRDocument object using the [CreateFRDocumentFromImage](/fine-reader/engine/api-reference/engine-object-iengine-interface/creation-methods/createfrdocumentfromimage-method) method of the Engine object. This method creates the FRDocument object and loads images from the specified file.
  * Create the FRDocument object with the help of the [CreateFRDocument](/fine-reader/engine/api-reference/engine-object-iengine-interface/creation-methods/createlessobjectgreater-methods) method of the Engine object, then add images to the created FRDocument object from file (use the [AddImageFile](/fine-reader/engine/api-reference/document-related-objects/frdocument/addimagefile-method), [AddImageFileWithPassword](/fine-reader/engine/api-reference/document-related-objects/frdocument/addimagefilewithpassword-method), or [AddImageFileWithPasswordCallback](/fine-reader/engine/api-reference/document-related-objects/frdocument/addimagefilewithpasswordcallback-method) method of the FRDocument object).

  ### C\#

  ```csharp theme={null}
  // Create the FRDocument object from an image file
  FREngine.IFRDocument frDocument = engine.CreateFRDocumentFromImage( "C:\\MyImage.tif", null );
  ```

  ### C++ (COM)

  ```cpp theme={null}
  // Create the FRDocument object from an image file
  FREngine::IFRDocumentPtr frDocument = Engine->CreateFRDocumentFromImage( L"C:\\MyImage.tif", 0 );
  ```
</Accordion>

<Accordion title="Step 4. Document recognition">
  To recognize a document, we suggest that you use the analysis and recognition methods of the FRDocument object. This object provides a whole array of methods for document analysis, recognition, and synthesis. The most convenient method which provides document analysis, recognition, and synthesis all-in-one is the [Process](/fine-reader/engine/api-reference/document-related-objects/frdocument/process-method) method. It also uses simultaneous processing features of multiprocessor and multicore systems in the most efficient manner. However, you can also perform consecutive preprocessing, analysis, recognition, and synthesis using [Preprocess](/fine-reader/engine/api-reference/document-related-objects/frdocument/preprocess-method), [Analyze](/fine-reader/engine/api-reference/document-related-objects/frdocument/analyze-method), [Recognize](/fine-reader/engine/api-reference/document-related-objects/frdocument/recognize-method), and [Synthesize](/fine-reader/engine/api-reference/document-related-objects/frdocument/synthesize-method) methods.

  ### C\#

  ```csharp theme={null}
  // Analyze, recognize, and synthesize the document
  // There is no need for additional parameters because they are set up by the processing profile
  frDocument.Process( null );
  ```

  ### C++ (COM)

  ```cpp theme={null}
  // Analyze, recognize, and synthesize the document
  // There is no need for additional parameters because they are set up by the processing profile
  frDocument->Process( 0 );
  ```
</Accordion>

<Accordion title="Step 5. Document export">
  To save a recognized document, you can use the [Export](/fine-reader/engine/api-reference/document-related-objects/frdocument/export-method) method of the [FRDocument](/fine-reader/engine/api-reference/document-related-objects/frdocument) object by assigning the [FileExportFormatEnum](/fine-reader/engine/api-reference/enumerations/fileexportformatenum) constant as one of the parameters. You can change the default parameters of export using the corresponding export object. Please see [Additional optimization for specific tasks](/fine-reader/engine/guided-tour/basic-usage-scenarios-implementation/document-conversion#optimization) below for further information.

  After you have finished your work with the FRDocument object, release all the resources that were used by this object. Use the [IFRDocument::Close](/fine-reader/engine/api-reference/document-related-objects/frdocument/close-method) method.

  ### C\#

  ```csharp theme={null}
  // Save the recognized document in a structured format
  frDocument.Export( "C:\\Data.json", FREngine.FileExportFormatEnum.FEF_JSON, null );
  // Release the FRDocument object
  frDocument.Close();
  ```

  ### C++ (COM)

  ```cpp theme={null}
  // Save the recognized document in a structured format
  frDocument->Export( L"C:\\Data.json", FREngine::FEF_JSON, 0 );
  // Release the FRDocument object
  frDocument->Close();
  ```
</Accordion>

<Accordion title="Step 6. Unloading ABBYY FineReader Engine">
  After finishing your work with ABBYY FineReader Engine, you need to unload the [Engine](/fine-reader/engine/api-reference/engine-object-iengine-interface) object. To do this, use the [DeinitializeEngine](/fine-reader/engine/api-reference/functions/deinitializeengine-function) exported function.

  ### C\#

  ```csharp theme={null}
  public class EngineLoader : IDisposable
  {
      // Unload FineReader Engine
      public void Dispose()
      {
          if (engine == null)
          {
              // Engine was not loaded
              return;
          }
          engine = null;
          // Deleting all objects before FreeLibrary call
          GC.Collect();
          GC.WaitForPendingFinalizers();
          GC.Collect();
          int hresult = deinitializeEngine();
   
          hresult = dllCanUnloadNow();
          if (hresult == 0)
          {
              FreeLibrary(dllHandle);
          }
          dllHandle = IntPtr.Zero;
          initializeEngine = null;
          deinitializeEngine = null;
          dllCanUnloadNow = null;
          // throwing exception after cleaning up
          Marshal.ThrowExceptionForHR(hresult);
      }
      // Kernel32.dll functions
      [DllImport("kernel32.dll")]
      private static extern IntPtr LoadLibraryEx(string dllToLoad, IntPtr reserved, uint flags);
      private const uint LOAD_WITH_ALTERED_SEARCH_PATH = 0x00000008;
      [DllImport("kernel32.dll")]
      private static extern IntPtr GetProcAddress(IntPtr hModule, string procedureName);
      [DllImport("kernel32.dll")]
      private static extern bool FreeLibrary(IntPtr hModule);
      // FREngine.dll functions
      [UnmanagedFunctionPointer(CallingConvention.StdCall, CharSet = CharSet.Unicode)]
      private delegate int InitializeEngine( string customerProjectId, string LicensePath, string LicensePassword, , , , ref FREngine.IEngine engine);
      [UnmanagedFunctionPointer(CallingConvention.StdCall)]
      private delegate int DeinitializeEngine();
      [UnmanagedFunctionPointer(CallingConvention.StdCall)]
      private delegate int DllCanUnloadNow();
      // private variables
      private FREngine.IEngine engine = null;
      // Handle to FREngine.dll
      private IntPtr dllHandle = IntPtr.Zero;
      private InitializeEngine initializeEngine = null;
      private DeinitializeEngine deinitializeEngine = null;
      private DllCanUnloadNow dllCanUnloadNow = null;
  }
  ```

  ### C++ (COM)

  ```cpp theme={null}
  void UnloadFREngine()
  {
   if( libraryHandle == 0 ) {
    return;
   }
   // Release Engine object
   Engine = 0;
   // Deinitialize FineReader Engine
   typedef HRESULT ( STDAPICALLTYPE* DeinitializeEngineFunc )();
   DeinitializeEngineFunc pDeinitializeEngine =
    ( DeinitializeEngineFunc )GetProcAddress( libraryHandle, "DeinitializeEngine" );
   if( pDeinitializeEngine == 0 || pDeinitializeEngine() != S_OK ) {
    throw L"Error while unloading ABBYY FineReader Engine";
   }
   // Now it's safe to free the FREngine.dll library
   FreeLibrary( libraryHandle );
   libraryHandle = 0;
  }
  ```
</Accordion>

## Required resources

You can use the [FREngineDistribution.csv](/fine-reader/engine/distribution/distribution-windows/distribution-kit/working-with-the-frenginedistributioncsv-file) file to automatically create a list of files required for your application to function. For processing with this scenario, select in the column 5 (RequiredByModule) the following values:

Core

Core.Resources

Opening

Opening, Processing

Processing

Processing.OCR

Processing.OCR, Processing.ICR

Processing.OCR.NaturalLanguages

Processing.OCR.NaturalLanguages, Processing.ICR.NaturalLanguages

Export

Export, Processing

If you modify the standard scenario, change the required modules accordingly. You also need to specify the interface languages, recognition languages and any additional features which your application uses (such as, for example, Opening.PDF if you need to open PDF files, or Processing.OCR.CJK if you need to recognize texts in [CJK languages](/fine-reader/engine/guided-tour/advanced-techniques/recognizing-cjk-languages#cjk)). See [Working with the FREngineDistribution.csv File](/fine-reader/engine/distribution/distribution-windows/distribution-kit/working-with-the-frenginedistributioncsv-file) for further details.

## Additional optimization for specific tasks

Below is the overview of the Help topics containing additional information regarding customization of settings at different stages of the document conversion to an editable format:

* Scanning - *Windows Only*
  * [Scanning](/fine-reader/engine/guided-tour/basic-usage-scenarios-implementation/scanning)<br />Description of the ABBYY FineReader Engine scenario for document scanning.
* Recognition
  * [Tuning Parameters of Preprocessing, Analysis, Recognition, and Synthesis](/fine-reader/engine/guided-tour/advanced-techniques/tuning-parameters-of-preprocessing-analysis-recognition-and-synthesis)<br />Customization of document processing using objects of analysis, recognition and synthesis parameters.
  * [PageProcessingParams Object](/fine-reader/engine/api-reference/parameter-objects/preprocessing-analysis-recognition-and-synthesis-parameters/pageprocessingparams)<br />This object enables the customization of analysis and recognition parameters. Using this object, you can indicate which image and text characteristics must be detected (inverted image, orientation, barcodes, recognition language, recognition error margin).
  * [SynthesisParamsForPage Object](/fine-reader/engine/api-reference/parameter-objects/preprocessing-analysis-recognition-and-synthesis-parameters/synthesisparamsforpage)<br />This object includes parameters responsible for restoration of a page formatting during synthesis.
  * [SynthesisParamsForDocument Object](/fine-reader/engine/api-reference/parameter-objects/preprocessing-analysis-recognition-and-synthesis-parameters/synthesisparamsfordocument)<br />This object enables customization of the document synthesis: restoration of its structure and formatting.
  * [MultiProcessingParams Object](/fine-reader/engine/api-reference/parameter-objects/multiprocessingparams) - *Implemented for Linux and Windows* <br />Simultaneous processing may be useful when processing a large number of images. In this case, the processing load will be spread over the processor cores during image opening and preprocessing, layout analysis, recognition, and export, which makes it possible to speed up processing.<br />Reading modes (simultaneous or consecutive) are set using the MultiProcessingMode property. The RecognitionProcessesCount property controls the number of processes that may be started.
* Export
  * [Tuning Export Parameters](/fine-reader/engine/guided-tour/advanced-techniques/tuning-export-parameters)<br />Customization of the document export using export parameters objects.
  * [XMLExportParams Object](/fine-reader/engine/api-reference/parameter-objects/export-parameters/xmlexportparams)<br />This object provides the settings of export to XML format.
  * [JsonExportParams Object](/fine-reader/engine/api-reference/parameter-objects/export-parameters/jsonexportparams)<br />This object provides the settings of export to JSON format.

## See also

[Basic Usage Scenarios Implementation](/fine-reader/engine/guided-tour/basic-usage-scenarios-implementation)