Class AdvancedOcrResultBase

Base class for advanced OCR results that support searchable PDF generation

Inheritance

System.Object

AdvancedOcrResultBase

OcrDocAdvancedResult

OcrPhotoResult

Implements

IronSoftware.Abstractions.Ocr.IOcrResult

Namespace: IronOcr

Assembly: IronOcr.dll

Syntax

public abstract class AdvancedOcrResultBase : Object, IOcrResult

Constructors

AdvancedOcrResultBase()

Declaration

protected AdvancedOcrResultBase()

Properties

Confidence

OCR statistical accuracy confidence as an average of every character.

1 = 100%, 0 = 0%.

Declaration

public abstract double Confidence { get; }

Property Value

Type	Description
System.Double

Text

All OCR texts from OcrInput.

Declaration

public abstract string Text { get; }

Property Value

Type	Description
System.String

Methods

SaveAsSearchablePdf(String, Boolean, String, String)

Exports the OCR result as a searchable PDF document and optionally saves it to a file.

A searchable PDF overlays invisible OCR text on the original image, allowing text selection and search while preserving the original appearance.

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Usage:

// Load OCR input
var input = new IronOcr.OcrInput();
input.LoadPdf("scanned.pdf");
// Instantiate OCR engine and enable searchable PDF rendering
var ocr = new IronOcr.IronTesseract();
ocr.Configuration.RenderSearchablePdf = true;
// Read the document
var result = ocr.ReadPhoto(input);
// Export and save as searchable PDF
byte[] pdfBytes = result.SaveAsSearchablePdf("output.pdf");
// Or with custom font for UTF-8 support (e.g., for Polish text)
byte[] pdfBytes = result.SaveAsSearchablePdf(
    Path: "output.pdf",
    ApplyFilters: false,
    CustomFontFile: @"C:\Fonts\DejaVuSans.ttf",
    CustomFontName: "DejaVu Sans");
// The file is saved and bytes are also returned for further processing if needed

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Declaration

public byte[] SaveAsSearchablePdf(string Path = null, bool ApplyFilters = false, string CustomFontFile = null, string CustomFontName = null)

Parameters

Type	Name	Description
System.String	Path	Optional. The file path where the PDF will be saved. If `null`, the PDF is not saved to disk.
System.Boolean	ApplyFilters	Optional. If `true`, applies image filters to enhance the output PDF quality. Default is `false`.
System.String	CustomFontFile	Optional. Path to a custom font file (.ttf, .otf, .ttc) to use for rendering text in the PDF. Useful for languages requiring full UTF-8 support (e.g., Polish, Arabic, Chinese). If not specified, the default TimesNewRoman font is used.
System.String	CustomFontName	Optional. Name of the custom font. If not provided, the font name will be automatically extracted from the font file metadata. This parameter is only used when `CustomFontFile` is specified.

Returns

Type	Description
System.Byte[]	A byte array containing the searchable PDF document.

Remarks

Important Considerations:

Configuration Required: You must set IronTesseract.Configuration.RenderSearchablePdf = true before reading the document, otherwise this method will throw an exception.

Performance: The PDF bytes are cached after first generation, so subsequent calls return immediately without regenerating.

Filters: Setting ApplyFilters to true applies image enhancement filters to improve PDF quality.

File Path Optional: If Path is null, the PDF is not saved to disk but the bytes are still returned.

Custom Fonts: Use CustomFontFile to provide a font with full UTF-8 support for languages like Polish, Arabic, Chinese, etc. The default TimesNewRoman has limited character support.

Related Documentation:

How-To Guide: Learn more about creating searchable PDFs

API Reference: See related searchable PDF methods

Exceptions

Type	Condition
IronOcrProductException	Thrown when `IronTesseract.Configuration.RenderSearchablePdf` was not set to `true` before reading the document.
IronOcrInputException	Thrown when the custom font file is invalid, inaccessible, or contains malicious content.

SaveAsSearchablePdfBytes(Boolean, String, String)

Exports the OCR result as a searchable PDF document and returns it as a byte array.

A searchable PDF overlays invisible OCR text on the original image, allowing text selection and search while preserving the original appearance.

------------------------------------------------

Usage:

// Load OCR input
var input = new IronOcr.OcrInput();
input.LoadPdf("scanned.pdf");
// Instantiate OCR engine and enable searchable PDF rendering
var ocr = new IronOcr.IronTesseract();
ocr.Configuration.RenderSearchablePdf = true;
// Read the document
var result = ocr.ReadPhoto(input);
// Export as searchable PDF bytes
byte[] pdfBytes = result.SaveAsSearchablePdfBytes();
// Or with custom font for UTF-8 support
byte[] pdfBytes = result.SaveAsSearchablePdfBytes(
    ApplyFilters: false,
    CustomFontFile: @"C:\Fonts\DejaVuSans.ttf");
System.IO.File.WriteAllBytes("output.pdf", pdfBytes);

------------------------------------------------

Declaration

public byte[] SaveAsSearchablePdfBytes(bool ApplyFilters = false, string CustomFontFile = null, string CustomFontName = null)

Parameters

Type	Name	Description
System.Boolean	ApplyFilters	Optional. If `true`, applies image filters to enhance the output PDF quality. Default is `false`.
System.String	CustomFontFile	Optional. Path to a custom font file (.ttf, .otf, .ttc) to use for rendering text in the PDF. Useful for languages requiring full UTF-8 support (e.g., Polish, Arabic, Chinese). If not specified, the default TimesNewRoman font is used.
System.String	CustomFontName	Optional. Name of the custom font. If not provided, the font name will be automatically extracted from the font file metadata. This parameter is only used when `CustomFontFile` is specified.

Returns

Type	Description
System.Byte[]	A byte array containing the searchable PDF document.

Remarks

Important Considerations:

Configuration Required: You must set IronTesseract.Configuration.RenderSearchablePdf = true before reading the document, otherwise this method will throw an exception.

Performance: The PDF bytes are cached after first generation, so subsequent calls return immediately without regenerating.

Filters: Setting ApplyFilters to true applies image enhancement filters to improve PDF quality.

Custom Fonts: Use CustomFontFile to provide a font with full UTF-8 support for languages like Polish, Arabic, Chinese, etc. The default TimesNewRoman has limited character support.

Related Documentation:

How-To Guide: Learn more about creating searchable PDFs

API Reference: See related searchable PDF methods

Exceptions

Type	Condition
IronOcrProductException	Thrown when `IronTesseract.Configuration.RenderSearchablePdf` was not set to `true` before reading the document.
IronOcrInputException	Thrown when the custom font file is invalid, inaccessible, or contains malicious content.

SaveAsSearchablePdfStream(Boolean, String, String)

Exports the OCR result as a searchable PDF document and returns it as a Stream.

A searchable PDF overlays invisible OCR text on the original image, allowing text selection and search while preserving the original appearance.

------------------------------------------------

Usage:

// Load OCR input
var input = new IronOcr.OcrInput();
input.LoadPdf("scanned.pdf");
// Instantiate OCR engine and enable searchable PDF rendering
var ocr = new IronOcr.IronTesseract();
ocr.Configuration.RenderSearchablePdf = true;
// Read the document
var result = ocr.ReadPhoto(input);
// Export as searchable PDF stream
Stream pdfStream = result.SaveAsSearchablePdfStream();
// Or with custom font for UTF-8 support
Stream pdfStream = result.SaveAsSearchablePdfStream(
    ApplyFilters: false,
    CustomFontFile: @"C:\Fonts\DejaVuSans.ttf");
// Use the stream (e.g., send via HTTP response, save to database, etc.)

------------------------------------------------

Declaration

public Stream SaveAsSearchablePdfStream(bool ApplyFilters = false, string CustomFontFile = null, string CustomFontName = null)

Parameters

Type	Name	Description
System.Boolean	ApplyFilters	Optional. If `true`, applies image filters to enhance the output PDF quality. Default is `false`.
System.String	CustomFontFile	Optional. Path to a custom font file (.ttf, .otf, .ttc) to use for rendering text in the PDF. Useful for languages requiring full UTF-8 support (e.g., Polish, Arabic, Chinese). If not specified, the default TimesNewRoman font is used.
System.String	CustomFontName	Optional. Name of the custom font. If not provided, the font name will be automatically extracted from the font file metadata. This parameter is only used when `CustomFontFile` is specified.

Returns

Type	Description
System.IO.Stream	A Stream containing the searchable PDF document.

Remarks

Important Considerations:

Configuration Required: You must set IronTesseract.Configuration.RenderSearchablePdf = true before reading the document, otherwise this method will throw an exception.

Performance: This method returns a new MemoryStream containing the cached PDF bytes, so subsequent calls create new streams but don't regenerate the PDF.

Filters: Setting ApplyFilters to true applies image enhancement filters to improve PDF quality.

Custom Fonts: Use CustomFontFile to provide a font with full UTF-8 support for languages like Polish, Arabic, Chinese, etc. The default TimesNewRoman has limited character support.

Related Documentation:

How-To Guide: Learn more about creating searchable PDFs

API Reference: See related searchable PDF methods

Exceptions

Type	Condition
IronOcrProductException	Thrown when `IronTesseract.Configuration.RenderSearchablePdf` was not set to `true` before reading the document.
IronOcrInputException	Thrown when the custom font file is invalid, inaccessible, or contains malicious content.

Implements

IronSoftware.Abstractions.Ocr.IOcrResult