Class IronTesseract
IronTesseract is a comprehensive managed class for performing Tesseract OCR in .Net applications.
IronTesseract natively supports Tesseract 3, 4 and 5 engines, and will automatically install all required binaries and language packs (tessdata) files.
Inheritance
Namespace: IronOcr
Assembly: IronOcr.dll
Syntax
public class IronTesseract : ObjectConstructors
IronTesseract()
Public constructor. Creates a default instance of IronTesseract
Declaration
public IronTesseract()IronTesseract(TesseractConfiguration)
Public constructor. Creates an instance of IronTesseract with a customized TesseractConfiguration.
This allows advanced developers to fine tune Tesseract behavior.
Declaration
public IronTesseract(TesseractConfiguration Configuration)Parameters
| Type | Name | Description |
|---|---|---|
| TesseractConfiguration | Configuration |
Fields
Configuration
An instance of TesseractConfiguration which allows fine-grained control of the underlying Tesseract OCR Engine.
Options include: Language file detail level. Page Segmentation Mode and access to the entire API of tesseract settings variables.
Declaration
public TesseractConfiguration ConfigurationField Value
| Type | Description |
|---|---|
| TesseractConfiguration |
Properties
Language
The Natural Language of the documents Which IronTesseract will read.
Default is English. Additional languages can be installed easily using Nuget https://www.nuget.org/packages?q=IronOcr.Languages or downloaded from https://ironsoftware.com/csharp/ocr/languages/
We may use multiple languages packs simultaneously with the UseMultipleLanguages method.
We can use custom Tesseract .tessdata language packs with the UseCustomTesseractLanguageFile(String) method.
Declaration
public OcrLanguage Language { get; set; }Property Value
| Type | Description |
|---|---|
| OcrLanguage |
See Also
MultiThreaded
Read multiple PDF pages and images simultaneously on different threads
Declaration
public bool MultiThreaded { get; set; }Property Value
| Type | Description |
|---|---|
| System.Boolean |
Methods
AddSecondaryLanguage(OcrLanguage)
IronTesseract will use multiple tesseract language files simultaneously. MultilingualOCR.
Any number of secondary languages may be added. Speed and performance may be affected.
Declaration
public void AddSecondaryLanguage(OcrLanguage SecondaryLanguage)Parameters
| Type | Name | Description |
|---|---|---|
| OcrLanguage | SecondaryLanguage | An additional OcrLanguage |
AddSecondaryLanguage(String)
IronTesseract will use multiple tesseract language files simultaneously. MultilingualOCR using a custom .traineddata tesseract 3,4 or 5 language file.
Any number of secondary languages may be added. Speed and performance may be affected.
Declaration
public void AddSecondaryLanguage(string CustomLanguagePath)Parameters
| Type | Name | Description |
|---|---|---|
| System.String | CustomLanguagePath | File path to a .traineddata tesseract language pack. |
ClearSecondaryLanguages()
Removes all languages add by AddSecondaryLanguage(OcrLanguage) or AddSecondaryLanguage(String)
Declaration
public void ClearSecondaryLanguages()Read(OcrInput)
Reads text from an OcrInput object and returns an OcrResult object.
OcrInput is the preferred input type because it allows for OCR of multi-paged documents, and allows images to be enhanced before OCR to obtain faster, more accurate results.
There are also other overloads of this method that allow for Images and PDFs to be read directly as File paths and Bitmaps.
Declaration
public OcrResult Read(OcrInput Input)Parameters
| Type | Name | Description |
|---|---|---|
| OcrInput | Input | An OcrInput document which can contain one or more images and PDFs |
Returns
| Type | Description |
|---|---|
| OcrResult | A OcrResult object containing text, and detailed, structured information about the extracted text content. |
Read(AnyBitmap)
Reads text from a IronSoftware.Drawing.AnyBitmap Image file and returns an OcrResult object.
Declaration
public OcrResult Read(AnyBitmap Image)Parameters
| Type | Name | Description |
|---|---|---|
| IronSoftware.Drawing.AnyBitmap | Image | An IronSoftware.Drawing.AnyBitmap, SixLabor.ImageSharp.Image, SkiaSharp.SKBitmap, SkiaSharp.SKImage, Microsoft.Maui.Graphics.Platform.PlatformImage, System.Drawing.Bitmap, or System.Drawing.Image |
Returns
| Type | Description |
|---|---|
| OcrResult | A OcrResult object containing text, and detailed, structured information about the extracted text content. |
Read(AnyBitmap, CropRectangle)
Reads text from a region of a IronSoftware.Drawing.AnyBitmap Image file and returns an OcrResult object.
Declaration
public OcrResult Read(AnyBitmap Image, CropRectangle ContentArea)Parameters
| Type | Name | Description |
|---|---|---|
| IronSoftware.Drawing.AnyBitmap | Image | An IronSoftware.Drawing.AnyBitmap, SixLabor.ImageSharp.Image, SkiaSharp.SKBitmap, SkiaSharp.SKImage, Microsoft.Maui.Graphics.Platform.PlatformImage, System.Drawing.Bitmap, or System.Drawing.Image |
| IronSoftware.Drawing.CropRectangle | ContentArea | Specifies a region within the image to extract text from as a IronSoftware.Drawing.CropRectangle with X, Y Width and Height in pixels. Setting a ContentArea can improve OCR speed. |
Returns
| Type | Description |
|---|---|
| OcrResult | A OcrResult object containing text, and detailed, structured information about the extracted text content. |
Read(String)
Reads text from an Image file and returns an OcrResult object.
Declaration
public OcrResult Read(string ImagePath)Parameters
| Type | Name | Description |
|---|---|---|
| System.String | ImagePath | Path to an image file. |
Returns
| Type | Description |
|---|---|
| OcrResult | A OcrResult object containing text, and detailed, structured information about the extracted text content. |
Read(String, CropRectangle)
Reads text from a region of an Image file and returns an OcrResult object.
Declaration
public OcrResult Read(string ImagePath, CropRectangle ContentArea)Parameters
| Type | Name | Description |
|---|---|---|
| System.String | ImagePath | Path to an image file. |
| IronSoftware.Drawing.CropRectangle | ContentArea | Specifies a region within the image to extract text from as a IronSoftware.Drawing.CropRectangle with X, Y Width and Height in pixels. Setting a ContentArea can improve OCR speed. |
Returns
| Type | Description |
|---|---|
| OcrResult | A OcrResult object containing text, and detailed, structured information about the extracted text content. |
ReadAsync(OcrInput, Int32)
Reads text from an OcrInput object and returns an OcrResult object.
OcrInput is the preferred input type because it allows for OCR of multi-paged documents, and allows images to be enhanced before OCR to obtain faster, more accurate results.
There are also other overloads of this method that allow for Images and PDFs to be read directly as File paths and Bitmaps.
Declaration
public OcrReadTask ReadAsync(OcrInput Input, int TimeoutMs = -1)Parameters
| Type | Name | Description |
|---|---|---|
| OcrInput | Input | An OcrInput document which can contain one or more images and PDFs |
| System.Int32 | TimeoutMs | Optional timeout in milliseconds, after which the Ocr read will be cancelled. Not supported in .NET 4.0 |
Returns
| Type | Description |
|---|---|
| OcrReadTask | A task that represents the asynchronous read operation. The value of the System.Threading.Tasks.Task`1.Result property contains an OcrResult object containing text, and detailed, structured information about the extracted text content. |
ReadAsync(AnyBitmap, CropRectangle, Int32)
Reads text from an IronSoftware.Drawing.AnyBitmap object and returns an OcrResult object.
Declaration
public Task<OcrResult> ReadAsync(AnyBitmap Image, CropRectangle ContentArea = null, int TimeoutMs = -1)Parameters
| Type | Name | Description |
|---|---|---|
| IronSoftware.Drawing.AnyBitmap | Image | An IronSoftware.Drawing.AnyBitmap object |
| IronSoftware.Drawing.CropRectangle | ContentArea | Specifies a region within the image to extract text from as a IronSoftware.Drawing.CropRectangle with X, Y Width and Height in pixels. Setting a ContentArea can improve OCR speed. |
| System.Int32 | TimeoutMs | Optional timeout in milliseconds, after which the Ocr read will be cancelled. Not supported in .NET 4.0 |
Returns
| Type | Description |
|---|---|
| System.Threading.Tasks.Task<OcrResult> | A task that represents the asynchronous read operation. The value of the System.Threading.Tasks.Task`1.Result property contains an OcrResult object containing text, and detailed, structured information about the extracted text content. |
ReadAsync(String, CropRectangle, Int32)
Reads text from an Image file and returns an OcrResult object.
Declaration
public OcrReadTask ReadAsync(string ImagePath, CropRectangle ContentArea = null, int TimeoutMs = -1)Parameters
| Type | Name | Description |
|---|---|---|
| System.String | ImagePath | Path to an image file. |
| IronSoftware.Drawing.CropRectangle | ContentArea | Specifies a region within the image to extract text from as a IronSoftware.Drawing.CropRectangle with X, Y Width and Height in pixels. Setting a ContentArea can improve OCR speed. |
| System.Int32 | TimeoutMs | Optional timeout in milliseconds, after which the Ocr read will be cancelled. Not supported in .NET 4.0 |
Returns
| Type | Description |
|---|---|
| OcrReadTask | A task that represents the asynchronous read operation. The value of the System.Threading.Tasks.Task`1.Result property contains an OcrResult object containing text, and detailed, structured information about the extracted text content. |
UseCustomTesseractLanguageFile(String)
IronTesseract will use a tesseract .traineddata language file as its only OCR language.
https://github.com/tesseract-ocr/tessdata
Declaration
public void UseCustomTesseractLanguageFile(string TrainedDataPath)Parameters
| Type | Name | Description |
|---|---|---|
| System.String | TrainedDataPath | File path to a .traineddata file. These can be downloaded from https://github.com/tesseract-ocr/tessdata or generated using Tesseract command line. |
Events
OcrProgress
An Event which can be used to track OCR progress and inform users of OCR performance and progress.
Progress is reported via the OcrProgressEventsArgs class
Declaration
public event EventHandler<OcrProgressEventsArgs> OcrProgressEvent Type
| Type | Description |
|---|---|
| System.EventHandler<OcrProgressEventsArgs> |
Examples
myIronTesseract.OcrProgress += (object o, IronOcr.Events.OcrProgressEventsArgs e) =>
{
Console.WriteLine(e.ProgressPercent + "% " + e.Duration.TotalSeconds+"s" );
}