Splitters behavior

Splitter processor output contains split information for the input document, including a confidence score. The Document AI API outputs a Document JSON object, and the output format uses the entities field for representing document splits. Additional information depends on the specific type of splitter.

• Entity.type specifies the document classification. For a full list of document types that can be identified, see the following lists.

• Entity.pageAnchor.pageRefs[] specifies the pages that contain each sub-document. Note that pageRefs[].page is zero-based and is the index into the document.pages[] field.

  Caution: Zero pageRefs[].page values omitted. When the API detects a page value of "0", that coordinate is omitted in the JSON response. For example, a response for the first two pages of a document would be: "pageRefs": [{}, {"page": "1"}]

Here is a typical JSON splitter response for a recognized document, indicating a form_140 class document on the second and third pages of the input file:

  {
    "textAnchor": {
      "textSegments": [
        {
          "startIndex": "5543",
          "endIndex": "10470"
        }
      ]
    },
    "type": "form_1040",
    "confidence": 0.8983272,
    "pageAnchor": {
      "pageRefs": [
        {
          "page": "1",
          "confidence": 0.8983272
        },
        {
          "page": "2",
          "confidence": 0.9636311
        }
      ]
    }
  },

Unlike custom classifier, splitters don't provide more than one class and their confidence scores.

The splitter is not designed to split logical documents that are over 30 pages long. Logical documents that are more than 30 pages long (for example a 40-page bank statement) may be split into two or more documents and classified separately.

Splitters identify page boundaries, but do not actually split the input document for you. The Document AI Toolbox SDK provides utility functions that can split the input document based on output from a splitter processor.

It's highly recommended that split predictions be reviewed by humans before actual file splitting, unless proven to be of acceptable accuracy for business needs.

Document types identified

This section details the document classes recognized by pretrained splitter processors.

Note: In general, the custom splitter is recommended over these pretrained splitters, because that can often exceed the accuracy of the pretrained processor with a practical number of samples in the dataset. Also, you likely have document classes (including annual versions) that are not covered by the pretrained processors.

^[1] The corresponding parser for this form does not support this doc type. This means that the splitter can identify and classify documents of this type, but Document AI does not provide a parser to extract information.

Output examples

Processors	Output samples

Code Samples

Splitters identify page boundaries, but don't actually split the input document for you. You can use Document AI Toolbox to physically split a PDF file by using the page boundaries. The following code samples print the page ranges without splitting the PDF:

Java

For more information, see the Document AI Java API reference documentation.

To authenticate to Document AI, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

import com.google.cloud.documentai.v1beta3.Document;
import com.google.cloud.documentai.v1beta3.DocumentProcessorServiceClient;
import com.google.cloud.documentai.v1beta3.DocumentProcessorServiceSettings;
import com.google.cloud.documentai.v1beta3.ProcessRequest;
import com.google.cloud.documentai.v1beta3.ProcessResponse;
import com.google.cloud.documentai.v1beta3.RawDocument;
import com.google.protobuf.ByteString;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.List;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeoutException;

public class ProcessSplitterDocument {
  public static void processSplitterDocument()
      throws IOException, InterruptedException, ExecutionException, TimeoutException {
    // TODO(developer): Replace these variables before running the sample.
    String projectId = "your-project-id";
    String location = "your-project-location"; // Format is "us" or "eu".
    String processerId = "your-processor-id";
    String filePath = "path/to/input/file.pdf";
    processSplitterDocument(projectId, location, processerId, filePath);
  }

  public static void processSplitterDocument(
      String projectId, String location, String processorId, String filePath)
      throws IOException, InterruptedException, ExecutionException, TimeoutException {
    // Initialize client that will be used to send requests. This client only needs
    // to be created
    // once, and can be reused for multiple requests. After completing all of your
    // requests, call
    // the "close" method on the client to safely clean up any remaining background
    // resources.
    String endpoint = String.format("%s-documentai.googleapis.com:443", location);
    DocumentProcessorServiceSettings settings =
        DocumentProcessorServiceSettings.newBuilder().setEndpoint(endpoint).build();
    try (DocumentProcessorServiceClient client = DocumentProcessorServiceClient.create(settings)) {
      // The full resource name of the processor, e.g.:
      // projects/project-id/locations/location/processor/processor-id
      // You must create new processors in the Cloud Console first
      String name =
          String.format("projects/%s/locations/%s/processors/%s", projectId, location, processorId);

      // Read the file.
      byte[] imageFileData = Files.readAllBytes(Paths.get(filePath));

      // Convert the image data to a Buffer and base64 encode it.
      ByteString content = ByteString.copyFrom(imageFileData);

      RawDocument document =
          RawDocument.newBuilder().setContent(content).setMimeType("application/pdf").build();

      // Configure the process request.
      ProcessRequest request =
          ProcessRequest.newBuilder().setName(name).setRawDocument(document).build();

      // Recognizes text entities in the PDF document
      ProcessResponse result = client.processDocument(request);
      Document documentResponse = result.getDocument();

      System.out.println("Document processing complete.");

      // Read the splitter output from the document splitter processor:
      // https://cloud.google.com/document-ai/docs/processors-list#processor_doc-splitter
      // This processor only provides text for the document and information on how
      // to split the document on logical boundaries. To identify and extract text,
      // form elements, and entities please see other processors like the OCR, form,
      // and specalized processors.
      List<Document.Entity> entities = documentResponse.getEntitiesList();
      System.out.printf("Found %d subdocuments:\n", entities.size());
      for (Document.Entity entity : entities) {
        float entityConfidence = entity.getConfidence();
        String pagesRangeText = pageRefsToString(entity.getPageAnchor().getPageRefsList());
        String subdocumentType = entity.getType();
        if (subdocumentType.isEmpty()) {
          System.out.printf(
              "%.2f%% confident that %s a subdocument.\n", entityConfidence * 100, pagesRangeText);
        } else {
          System.out.printf(
              "%.2f%% confident that %s a '%s' subdocument.\n",
              entityConfidence * 100, pagesRangeText, subdocumentType);
        }
      }
    }
  }

  // Converts page reference(s) to a string describing the page or page range.
  private static String pageRefsToString(List<Document.PageAnchor.PageRef> pageRefs) {
    if (pageRefs.size() == 1) {
      return String.format("page %d is", pageRefs.get(0).getPage() + 1);
    } else {
      long start = pageRefs.get(0).getPage() + 1;
      long end = pageRefs.get(1).getPage() + 1;
      return String.format("pages %d to %d are", start, end);
    }
  }
}

Node.js

For more information, see the Document AI Node.js API reference documentation.

To authenticate to Document AI, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

/**
 * TODO(developer): Uncomment these variables before running the sample.
 */
// const projectId = 'YOUR_PROJECT_ID';
// const location = 'YOUR_PROJECT_LOCATION'; // Format is 'us' or 'eu'
// const processorId = 'YOUR_PROCESSOR_ID'; // Create processor in Cloud Console
// const filePath = '/path/to/local/pdf';

const {DocumentProcessorServiceClient} =
  require('@google-cloud/documentai').v1beta3;

// Instantiates a client
const client = new DocumentProcessorServiceClient();

async function processDocument() {
  // The full resource name of the processor, e.g.:
  // projects/project-id/locations/location/processor/processor-id
  // You must create new processors in the Cloud Console first
  const name = `projects/${projectId}/locations/${location}/processors/${processorId}`;

  // Read the file into memory.
  const fs = require('fs').promises;
  const imageFile = await fs.readFile(filePath);

  // Convert the image data to a Buffer and base64 encode it.
  const encodedImage = Buffer.from(imageFile).toString('base64');

  const request = {
    name,
    rawDocument: {
      content: encodedImage,
      mimeType: 'application/pdf',
    },
  };

  // Recognizes text entities in the PDF document
  const [result] = await client.processDocument(request);

  console.log('Document processing complete.');

  // Read fields specificly from the specalized US drivers license processor:
  // https://cloud.google.com/document-ai/docs/processors-list#processor_us-driver-license-parser
  // retriving data from other specalized processors follow a similar pattern.
  // For a complete list of processors see:
  // https://cloud.google.com/document-ai/docs/processors-list
  //
  // OCR and other data is also present in the quality processor's response.
  // Please see the OCR and other samples for how to parse other data in the
  // response.
  const {document} = result;
  console.log(`Found ${document.entities.length} subdocuments:`);
  for (const entity of document.entities) {
    const conf = entity.confidence * 100;
    const pagesRange = pageRefsToRange(entity.pageAnchor.pageRefs);
    if (entity.type !== '') {
      console.log(
        `${conf.toFixed(2)}% confident that ${pagesRange} a "${
          entity.type
        }" subdocument.`
      );
    } else {
      console.log(
        `${conf.toFixed(2)}% confident that ${pagesRange} a subdocument.`
      );
    }
  }
}

// Converts a page ref to a string describing the page or page range.
const pageRefsToRange = pageRefs => {
  if (pageRefs.length === 1) {
    const num = parseInt(pageRefs[0].page) + 1 || 1;
    return `page ${num} is`;
  } else {
    const start = parseInt(pageRefs[0].page) + 1 || 1;
    const end = parseInt(pageRefs[1].page) + 1;
    return `pages ${start} to ${end} are`;
  }
};

Python

For more information, see the Document AI Python API reference documentation.

To authenticate to Document AI, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

from typing import Optional, Sequence

from google.api_core.client_options import ClientOptions
from google.cloud import documentai

# TODO(developer): Uncomment these variables before running the sample.
# project_id = "YOUR_PROJECT_ID"
# location = "YOUR_PROCESSOR_LOCATION" # Format is "us" or "eu"
# processor_id = "YOUR_PROCESSOR_ID" # Create processor before running sample
# processor_version = "rc" # Refer to https://cloud.google.com/document-ai/docs/manage-processor-versions for more information
# file_path = "/path/to/local/pdf"
# mime_type = "application/pdf" # Refer to https://cloud.google.com/document-ai/docs/file-types for supported file types


def process_document_splitter_sample(
    project_id: str,
    location: str,
    processor_id: str,
    processor_version: str,
    file_path: str,
    mime_type: str,
) -> None:
    # Online processing request to Document AI
    document = process_document(
        project_id, location, processor_id, processor_version, file_path, mime_type
    )

    # Read the splitter output from a document splitter/classifier processor:
    # e.g. https://cloud.google.com/document-ai/docs/processors-list#processor_procurement-document-splitter
    # This processor only provides text for the document and information on how
    # to split the document on logical boundaries. To identify and extract text,
    # form elements, and entities please see other processors like the OCR, form,
    # and specalized processors.

    print(f"Found {len(document.entities)} subdocuments:")
    for entity in document.entities:
        conf_percent = f"{entity.confidence:.1%}"
        pages_range = page_refs_to_string(entity.page_anchor.page_refs)

        # Print subdocument type information, if available
        if entity.type_:
            print(
                f"{conf_percent} confident that {pages_range} a '{entity.type_}' subdocument."
            )
        else:
            print(f"{conf_percent} confident that {pages_range} a subdocument.")


def page_refs_to_string(
    page_refs: Sequence[documentai.Document.PageAnchor.PageRef],
) -> str:
    """Converts a page ref to a string describing the page or page range."""
    pages = [str(int(page_ref.page) + 1) for page_ref in page_refs]
    if len(pages) == 1:
        return f"page {pages[0]} is"
    else:
        return f"pages {', '.join(pages)} are"




def process_document(
    project_id: str,
    location: str,
    processor_id: str,
    processor_version: str,
    file_path: str,
    mime_type: str,
    process_options: Optional[documentai.ProcessOptions] = None,
) -> documentai.Document:
    # You must set the `api_endpoint` if you use a location other than "us".
    client = documentai.DocumentProcessorServiceClient(
        client_options=ClientOptions(
            api_endpoint=f"{location}-documentai.googleapis.com"
        )
    )

    # The full resource name of the processor version, e.g.:
    # `projects/{project_id}/locations/{location}/processors/{processor_id}/processorVersions/{processor_version_id}`
    # You must create a processor before running this sample.
    name = client.processor_version_path(
        project_id, location, processor_id, processor_version
    )

    # Read the file into memory
    with open(file_path, "rb") as image:
        image_content = image.read()

    # Configure the process request
    request = documentai.ProcessRequest(
        name=name,
        raw_document=documentai.RawDocument(content=image_content, mime_type=mime_type),
        # Only supported for Document OCR processor
        process_options=process_options,
    )

    result = client.process_document(request=request)

    # For a full list of `Document` object attributes, reference this page:
    # https://cloud.google.com/document-ai/docs/reference/rest/v1/Document
    return result.document

The following code sample uses Document AI Toolbox to split a PDF file using the page boundaries from a processed Document.

Python

For more information, see the Document AI Python API reference documentation.

To authenticate to Document AI, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

from google.cloud.documentai_toolbox import document

# TODO(developer): Uncomment these variables before running the sample.
# Given a local document.proto or sharded document.proto from a splitter/classifier in path
# document_path = "path/to/local/document.json"
# pdf_path = "path/to/local/document.pdf"
# output_path = "resources/output/"


def split_pdf_sample(document_path: str, pdf_path: str, output_path: str) -> None:
    wrapped_document = document.Document.from_document_path(document_path=document_path)

    output_files = wrapped_document.split_pdf(
        pdf_path=pdf_path, output_path=output_path
    )

    print("Document Successfully Split")
    for output_file in output_files:
        print(output_file)