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Add OCR Bridge step

OCR Bridge is introduced to improve:

• Performance. The OCR Bridge step reduces throughput due to processing documents asynchronously without submitting redundant tasks to Control Tower Workers and receiving responses instantly in Control Tower.
• Usability. Only one step is needed to recognize a document whose output is compatible with a Tagging-over-Document (ToD) Manual Task.

OCR REST configuration properties

Property	Default value	Description
execution.bridge.task.queue	exec.<CT_HOST>.result.ocr	Name of the OCR Bridge queue
execution.bridge.prefetch.count	100	Prefetch count of the Bridge queue
execution.bridge.thread.count	20	Count of threads for consuming messages of the Bridge queue

OCR Bridge step

Input parameters

Parameter	Code	Default value	Description
Document URL column name	document_url_column_name	original_document_url	Document URL column name for processing by OCR
OCR Type	ocr_type	Enriched	OCR Type values: Standard and Enriched (prepare output for a ToD Manual Task)
S3 bucket name	s3_bucket_name	doc-upload	S3 bucket to store results
S3 folder name	s3_folder_name	empty	S3 folder to store results
OCR Provider	ocr_provider	Abbyy	OCR provider: ABBYY Google Vision Azure Form Recognition
OCR parameters JSON	ocr_parameters	See below	See the parameters in the table below.

OCR JSON. Default values

{
    "exportFormat":"xmlForCorrectedImage,xmlWithoutRecognitionVariants",
    "language": "English",
    "correctSkew": true,
    "correctOrientation": true,
    "writeRecognitionVariants": true,
    "invertImage": false,
    "discardColorImage": false,
    "skipPreprocessing": false,
    "useOnlyCustomRegions": false,
    "useDefaultPattern": false,
    "profile": "documentConversion",
    "removeGarbageSize": 0,
    "lowResolutionMode": false,
    "enhanceLocalContrast": false,
    "allowedRegionTypes": null,
    "changeDPI": 0,
    "version": "V_2",
    "storePreprocessedDoc": true,
    "textTypes": ["normal"],
    "timeout": 60
}

OCR parameters

Parameter	Values	Description
exportFormat		OCR API export format. You can define multiple export formats using a comma as a separator: xml,xmlForCorrectedImage. Mind that, for correct processing of a ToD Manual Tasks, you cannot use more than three export formats.
	txt	Default export format.
	xml	Contains characters or words along with their location in the original document (coordinates or frames).
	xmlWithoutRecognitionVariants	The same as xml but does not contain character-related data.
	xmlForCorrectedImage	The same as xml, except the location is taken from a processed or adjusted document.
	pdfSearchable
	html
language	English German so on	Predefined language. You can also define multiple languages using a comma as a separator: English,German,Polish.
correctSkew	boolean	The page skew is detected and automatically corrected.
correctOrientation	boolean	The page orientation is detected. If it differs from normal, it is rotated automatically.
writeRecognitionVariants	boolean	Causes the xml and xmlForCorrectedImage formats to contain all variants of characters or words that OCR considers a possible recognition result.
invertImage	boolean	Inverts images.
discardColorImage	boolean	Leaves only the black-and-white plane in a prepared image.
skipPreprocessing	boolean	Disables all preprocessing steps for a document. The default value is false. If you set to true, the convertTo and changeDPI parameters are disabled.
useOnlyCustomRegions	boolean	Skips the original analyzing stage and extracts information from custom regions only.
useDefaultPattern	boolean	If true, it requires applying the default pattern from the OCR application bundle.
profile	documentConversion	Converts documents into editable formats.
	textExtraction	Extracts text from documents.
	barcodeRecognition	Extracts barcodes.
removeGarbageSize	integer	Removes garbage from images: excess dots smaller than a specific size. Optional; valid value > 0 and -1 for the automatically detected garbage size.
lowResolutionMode	boolean	Improves the recognition of images with low resolution.
enhanceLocalContrast	boolean	Specifies whether the local contrast of an image should be increased.
convertTo	none	Automatically detects the file type and conversion to TIFF before processing (only conversion to TIFF is supported). Accepts images: PDF, PNG, JPG, JPEG.
changeDPI	integer [50 : 3200] valid range null or 0 for disable	Specifies a new value for the resolution, for example, changeDPI=300. The recommended resolution for a source image is 300 DPI for typical texts (10 pt or larger) and 400-600 DPI for texts in smaller fonts (9 pt or smaller).
version	V_2	ABBYY FRE 12
	V_1	ABBYY FRE 11
storePreprocessedDoc	boolean	Specifies whether preprocessed documents should be saved in the data storage.
textTypes	normal typewriter matrix ocrA ocrB e13b	Specifies the type of the text in the document. You can define several text types using a comma as a separator: normal,matrix.
timeout	integer	Sets the maximum allowed timeout in seconds for a single task execution by an OCR Worker. The timeout countdown starts when an OCR Worker starts executing a task. When the task execution exceeds the given timeout, the task is forcibly killed. If you do not set the value, the default value (0) is used, and your Business Process (BP) does not have time to process a task.

caution

If native_pdf_processing is set to true, the skipPreprocessing and convertTo parameters are disabled. Such parameters as changeDPI and storePreprocessedDoc take effect only on saving pages of an input PDF.

Output parameters

• OCR Result: document processing results in the JSON format

  • Code: ocr_result

  • Example:

  {
      "originalDocument": "https://minio-host/doc-upload/1.pdf",
      "documents": {
          "xmlForCorrectedImage": "https://minio-host/doc-upload/bp-id/task-id/1- xmlForCorrectedImage.xml",
          "xmlWithoutRecognitionVariants": "https://minio-host/doc-upload/bp-id/task-id/1-xmlWithoutRecognitionVariants.xml"
      },
      "pageDetails": "https://minio-host/doc-upload/bp-id/task-id/preprocessed/links.json"
  }
  

• Task ID: the ID of an OCR task

  • Code: task_id
  • Example: 066416ed-20e8-4e96-9df1-7f7e133f1211

• Meta Info JSON extended info for the ToD Manual Task

  • Code: meta_info_json
  • Example:

  {
      "pages": "https://minio-host/doc-upload/bp-id/task-id/preprocessed/links.json",
      "ocrXmlUrl": "https://minio-host/doc-upload/bp-id/task-id/1-xmlWithoutRecognitionVariants.xml",
      "imageUrl": "https://minio-host/doc-upload/1.pdf"
  }
  

• Process time: record process time in milliseconds

  • Code: _sys_ocr_process_time
  • Example: 24053

See a JSON example for https://minio-host/doc-upload/bp-id/task-id/preprocessed/links.json below:

[
    {
        "imgUrl": "https://minio-host/doc-upload/bp-id/task-id/preprocessed/1.png",
        "charsUrl": "https://minio-host/doc-upload/bp-id/task-id/preprocessed/1.json",
        "height": 3300,
        "width": 2550,
        "charsCount": 2216
    }
]

Create Business Process with OCR and ToD Manual Task

To build a BP with OCR and a ToD Manual Task, perform the following steps:

1. Create a BP.

   

2. To create an OCR Bridge step, in the Select an Operation menu, choose OCR Bridge.

   

3. On the Design tab > Create Bot Configuration, set up the OCR Bridge step.

   

   If you select Google Vision or Azure as your OCR Provider, check the default configuration. The following parameters must be specified:

   • OCR Type: Enriched
   • exportFormat: xmlForCorrectedImage,xmlWithoutRecognitionVariants
   • writeRecognitionVariants: true
   • skipPreprocessing: false
   • storePreprocessedDoc: true
   • timeout: 60

   

   caution

   If any of the settings are not configured as above for Google Vision or Azure, OCR throws an exception with the corresponding message.

   tip

   For more details on the configuration of multiple OCR providers, see Configure multiple OCR providers.

4. Click Save. The BP is now ready to process incoming documents via OCR.