Document type detection

Aspose.OCR for Java can automatically classify the content of an image or document page before running a specialized OCR workflow. This helps route mixed input batches to the most suitable recognition or post-processing pipeline.

Document type detection uses built-in rule-based logic combined with a neural model ported from Aspose.OCR for .NET.

Supported document types

The following document categories can be detected:

Document type	Description
DocType.UNKNOWN	Document type was not detected.
DocType.PICTURE	Photo, advertisement, billboard, packaging, or similar visual content.
DocType.HANDWRITTEN	Handwritten content.
DocType.BOOK	Book page or other primarily textual content.
DocType.FORMULA	Mathematical formula, equation, or expression.
DocType.TABLE	Table, form, or spreadsheet-like content.
DocType.PRESENTATION	Presentation slide.
DocType.SCIENTIFIC	Scientific article, report, paper, or technical publication.
DocType.INVOICE	Invoice, bill, receipt, or payment document.

Detecting document type

To detect document type, provide the collection of images to com.aspose.ocr.AsposeOCR.DetectDocumentType() method.

The method returns ArrayList<DocTypeOutput>. Each item contains:

Property	Type	Description
source	String	Image path or URL when available. Empty for in-memory input.
page	int	Zero-based page number.
docType	DocType	Detected document category.
confidence	float	Confidence score from 0.0 to 1.0.

import com.aspose.ocr.AsposeOCR;
import com.aspose.ocr.DocTypeOutput;
import com.aspose.ocr.InputType;
import com.aspose.ocr.OcrInput;

import java.util.ArrayList;

public class DetectDocumentTypeExample {
    public static void main(String[] args) throws Exception {
        OcrInput input = new OcrInput(InputType.SingleImage);
        input.add("invoice.png");

        try (AsposeOCR api = new AsposeOCR()) {
            ArrayList<DocTypeOutput> results = api.DetectDocumentType(input);

            for (DocTypeOutput result : results) {
                System.out.println("Source: " + result.source);
                System.out.println("Page: " + result.page);
                System.out.println("Document type: " + result.docType);
                System.out.println("Confidence: " + result.confidence);
            }
        }
    }
}

Detecting document types in a PDF

For multi-page documents, one DocTypeOutput item is returned for each processed page.

import com.aspose.ocr.AsposeOCR;
import com.aspose.ocr.DocTypeOutput;
import com.aspose.ocr.InputType;
import com.aspose.ocr.OcrInput;

import java.util.ArrayList;

public class DetectDocumentTypePdfExample {
    public static void main(String[] args) throws Exception {
        OcrInput input = new OcrInput(InputType.PDF);
        input.add("mixed-document.pdf", 0, 3);

        try (AsposeOCR api = new AsposeOCR()) {
            ArrayList<DocTypeOutput> results = api.DetectDocumentType(input);

            for (DocTypeOutput result : results) {
                System.out.println("Page " + result.page + ": "
                    + result.docType + " (" + result.confidence + ")");
            }
        }
    }
}