Syntax
C#
VB
Java
Objective-C
WinRT C#
C++
- (BOOL)startup:(nullable LTRasterCodecs *)rasterCodecs
documentWriter:(nullable LTDocumentWriter *)documentWriter
workDirectory:(nullable NSString *)workDirectory
engineDirectory:(nullable NSString *)engineDirectory
error:(NSError **)error
function Leadtools.Forms.Ocr.IOcrEngine.Startup(
rasterCodecs ,
documentWriter ,
workDirectory ,
startupParameters
)
Parameters
rasterCodecs
Optional instance of a RasterCodecs object to be used when loading image files from disk inside the engine. You can pass your own initialized instance of RasterCodecs to be used. The same object will then be used internally by the OCR engine when loading raster image files. Otherwise, pass null (Nothing in VB) and the IOcrEngine will create and use its own version of RasterCodecs when needed. Refer to RasterCodecsInstance for more information on how this parameter is used by the OCR engine during its lifetime, refer to OCR Engine and RasterCodecs/DocumentWriter Usage.
workDirectory
Optional path to a directory to be used when the engine saves temporary files. The IOcrEngine object will create various temporary files during recognition and document saving processes. It will use the path passed in workDirectory as the location where these temporary files will be created. You can pass null (Nothing in VB) to let the engine select the temporary directory of the current logged in user (TEMP).
In either case, the value of working directory of the current started IOcrEngine can be obtained through the WorkDirectory property.
The engine automatically deletes any temporary files created. However, if an unexpected error occurs (for example, an unhandled exception), some temporary files may still reside in the work directory after the application exits. A typical application may use a custom directory inside the application path and manually deletes any files that may reside there before calling Startup in case the previous instance of the application exited abnormally.
If the value of the
workDirectory
Optional path to a directory to be used when the engine saves temporary files. The
IOcrEngine object will create various temporary files during recognition and document saving processes. It will use the path passed in
workDirectory as the location where these temporary files will be created. You can pass
null (
Nothing in VB) to let the engine select the temporary directory of the current logged in user (
TEMP).
startupParameters
Optional startup parameter. The value of this parameter depends on the type of this IOcrEngine as follows:
Engine | startupParameters |
OcrEngineType.Advantage | The path to the folder containing the OCR engine files. If you pass null (Nothing in VB) to startupParameters
Optional startup parameter. The value of this parameter depends on the type of this IOcrEngine as follows:
|
OcrEngineType.Arabic | The path to the folder containing the OCR engine files. If you pass null (Nothing in VB) to startupParameters
Optional startup parameter. The value of this parameter depends on the type of this IOcrEngine as follows:
|
OcrEngineType.Professional | The path to the folder containing the OCR engine files. If you pass null (Nothing in VB) to startupParameters
Optional startup parameter. The value of this parameter depends on the type of this IOcrEngine as follows:
|
Example
The following example assumes you copied the OCR engine runtime files to C:\MyApp\Ocr.
using Leadtools;
using Leadtools.Codecs;
using Leadtools.Forms.Ocr;
using Leadtools.Forms.DocumentWriters;
public void StartupEngineExample()
{
// Use RasterCodecs to load an image file
// Note: You can let the engine load the image file directly as shown in the other examples
RasterCodecs codecs = new RasterCodecs();
RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.tif"));
// Assume you copied the engine runtime files to C:\MyApp\Ocr
string engineDir = @"C:\MyApp\Ocr";
// Store the engine work directory into a path inside our application
string workDir = @"C:\MyApp\OcrTemp";
// Delete all files in the work directory in case the previous version of our application exited abnormally and
// the engine did not get the chance to clean all of its temporary files (if any)
Directory.Delete(workDir, true);
// Re-create the work directory
Directory.CreateDirectory(workDir);
// Create an instance of the engine
using (IOcrEngine ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.Advantage, false))
{
// Show that the engine has not been started yet
Console.WriteLine("Before calling Startup, IsStarted = " + ocrEngine.IsStarted);
// Start the engine using our parameters
// Since we already have a RasterCodecs object, we can re-use it to save memory and resources
ocrEngine.Startup(codecs, null, workDir, engineDir);
// Make sure the engine is using our working directory
Console.WriteLine("workDir passed is {0}, the value of WorkDirectory after Startup is {1}", workDir, ocrEngine.WorkDirectory);
// Show that the engine has started fine
Console.WriteLine("After calling Startup, EngineType is {0}, IsStarted = {1}", ocrEngine.EngineType, ocrEngine.IsStarted);
// Maks sure the engine is using our own version of RasterCodecs
Debug.Assert(codecs == ocrEngine.RasterCodecsInstance);
// Create a page from the raster image as page to the document
IOcrPage ocrPage = ocrEngine.CreatePage(image, OcrImageSharingMode.AutoDispose);
// image belongs to the page and will be dispose when the page is disposed
// Recognize the page
// Note, Recognize can be called without calling AutoZone or manually adding zones. The engine will
// check and automatically auto-zones the page
ocrPage.Recognize(null);
// Create a file based document
using (IOcrDocument ocrDocument = ocrEngine.DocumentManager.CreateDocument(null, OcrCreateDocumentOptions.AutoDeleteFile))
{
// Add the page
ocrDocument.Pages.Add(ocrPage);
// No need for the page anymore
ocrPage.Dispose();
// Save the document we have as PDF
string pdfFileName = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.pdf");
ocrDocument.Save(pdfFileName, DocumentFormat.Pdf, null);
}
// Shutdown the engine
// Note: calling Dispose will also automatically shutdown the engine if it has been started
ocrEngine.Shutdown();
}
}
static class LEAD_VARS
{
public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}
Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.Forms.Ocr
Imports Leadtools.Forms.DocumentWriters
<TestMethod>
Public Sub StartupEngineExample()
' Use RasterCodecs to load an image file
' Note: You can let the engine load the image file directly as shown in the other examples
Dim codecs As New RasterCodecs()
Dim image As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.tif"))
' Assume you copied the engine runtime files to C:\MyApp\Ocr
Dim engineDir As String = "C:\MyApp\Ocr"
' Store the engine work directory into a path inside our application
Dim workDir As String = "C:\MyApp\OcrTemp"
' Delete all files in the work directory in case the previous version of our application exited abnormally and
' the engine did not get the chance to clean all of its temporary files (if any)
Directory.Delete(workDir, True)
' Re-create the work directory
Directory.CreateDirectory(workDir)
' Create an instance of the engine
Using ocrEngine As IOcrEngine = OcrEngineManager.CreateEngine(OcrEngineType.Advantage, False)
' Show that the engine has not been started yet
Console.WriteLine("Before calling Startup, IsStarted = " & ocrEngine.IsStarted)
' Start the engine using our parameters
' Since we already have a RasterCodecs object, we can re-use it to save memory and resources
ocrEngine.Startup(codecs, Nothing, workDir, engineDir)
' Make sure the engine is using our working directory
Console.WriteLine("workDir passed is {0}, the value of WorkDirectory after Startup is {1}", workDir, ocrEngine.WorkDirectory)
' Show that the engine has started fine
Console.WriteLine("After calling Startup, EngineType is {0}, IsStarted = {1}", ocrEngine.EngineType, ocrEngine.IsStarted)
' Maks sure the engine is using our own version of RasterCodecs
Debug.Assert(codecs Is ocrEngine.RasterCodecsInstance)
' Create a page from the raster image as page to the document
Dim ocrPage As IOcrPage = ocrEngine.CreatePage(image, OcrImageSharingMode.AutoDispose)
' image belongs to the page and will be dispose when the page is disposed
' Recognize the page
' Note, Recognize can be called without calling AutoZone or manually adding zones. The engine will
' check and automatically auto-zones the page
ocrPage.Recognize(Nothing)
' Create a file based document
Using ocrDocument As IOcrDocument = ocrEngine.DocumentManager.CreateDocument(Nothing, OcrCreateDocumentOptions.AutoDeleteFile)
' Add the page
ocrDocument.Pages.Add(ocrPage)
' No need for the page anymore
ocrPage.Dispose()
' Save the document we have as PDF
Dim pdfFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.pdf")
ocrDocument.Save(pdfFileName, DocumentFormat.Pdf, Nothing)
End Using
' Shutdown the engine
' Note: calling Dispose will also automatically shutdown the engine if it has been started
ocrEngine.Shutdown()
End Using
End Sub
Public NotInheritable Class LEAD_VARS
Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class