GroupDocs.Search for .NET 21.8 Release Notes

Major Features

There are the following features, enhancements, and fixes in this release:

• Implement OCR support for indexing

Full List of Issues Covering all Changes in this Release

Public API and Backward Incompatible Changes

Implement OCR support for indexing

This feature implements the ability to connect optical character recognition (OCR) on images inside individual image files, as well as on images embedded in documents.

Public API changes

Enumeration ImageLocation has been added to GroupDocs.Search.Options namespace.
Value Separate has been added to GroupDocs.Search.Options.ImageLocation enumeration.
Value Embedded has been added to GroupDocs.Search.Options.ImageLocation enumeration.
Value ContainerItem has been added to GroupDocs.Search.Options.ImageLocation enumeration.

Interface IOcrConnector has been added to GroupDocs.Search.Options namespace.
Method string Recognize(OcrContext) has been added to GroupDocs.Search.Options.IOcrConnector interface.

Class OcrIndexingOptions has been added to GroupDocs.Search.Options namespace.
Property bool EnabledForSeparateImages has been added to GroupDocs.Search.Options.OcrIndexingOptions class.
Property bool EnabledForEmbeddedImages has been added to GroupDocs.Search.Options.OcrIndexingOptions class.
Property IOcrConnector OcrConnector has been added to GroupDocs.Search.Options.OcrIndexingOptions class.

Property OcrIndexingOptions OcrIndexingOptions has been added to GroupDocs.Search.Options.IndexingOptions class.

Class OcrContext has been added to GroupDocs.Search.Options namespace.
Property Stream ImageStream has been added to GroupDocs.Search.Options.OcrContext class.
Property ImageLocation ImageLocation has been added to GroupDocs.Search.Options.OcrContext class.
Property string ImageFileExtension has been added to GroupDocs.Search.Options.OcrContext class.

Property OcrIndexingOptions OcrIndexingOptions has been added to GroupDocs.Search.Options.IndexingOptions class.

Property OcrIndexingOptions OcrIndexingOptions has been added to GroupDocs.Search.Options.TextOptions class.

Property OcrIndexingOptions OcrIndexingOptions has been added to GroupDocs.Search.Options.UpdateOptions class.

Constant string EmbeddedImageOcr has been added to GroupDocs.Search.Options.CommonFieldNames class.

Use cases

The following example demonstrates how to connect Aspose.OCR library for text recognition.

string indexFolder = @"c:\MyIndex";
string documentFolder = @"c:\MyDocuments";

// Creating an index
Index index = new Index(indexFolder);

// Setting the OCR indexing options
IndexingOptions options = new IndexingOptions();
options.OcrIndexingOptions.EnabledForSeparateImages = true;
options.OcrIndexingOptions.EnabledForEmbeddedImages = true;
options.OcrIndexingOptions.OcrConnector = new OcrConnector();

// Indexing documents in a document folder
index.Add(documentFolder, options);

// Searching in the index
SearchResult result = index.Search("Einstein");

...

// Implementing the OCR connector that uses Aspose.OCR library
public class OcrConnector : IOcrConnector
{
    public OcrConnector()
    {
    }

    public string Recognize(OcrContext context)
    {
        string extension = context.ImageFileExtension.ToLowerInvariant();
        if (context.ImageLocation == ImageLocation.Separate)
        {
            switch (extension)
            {
                case ".gif":
                case ".png":
                case ".jpg":
                case ".jpeg":
                case ".bmp":
                case ".tif":
                case ".tiff":
                case "":
                    return RecognizePrivate(context);

                default:
                    return null;
            }
        }
        else if (context.ImageLocation == ImageLocation.Embedded ||
            context.ImageLocation == ImageLocation.ContainerItem)
        {
            return RecognizePrivate(context);
        }
        else
        {
            throw new NotSupportedException("The image type is not supported: " + context.ImageLocation);
        }
    }

    private string RecognizePrivate(OcrContext context)
    {
        MemoryStream memoryStream = new MemoryStream((int)context.ImageStream.Length);
        context.ImageStream.CopyTo(memoryStream);

        AsposeOcr asposeOcr = new AsposeOcr();
        string result = asposeOcr.RecognizeImage(memoryStream);
        return result;
    }
}