OcrRuntimeFileCallback Delegate
Summary
Signature of the callback to use for redirecting OCR runtime files.
Syntax
Parameters
engine
Caller OCR engine.
runtimeFile
Runtime file information.
Return Value
The caller should return RasterExceptionCode.Success if the operation is successful, or an appropriate error code if needed. For instance:
Example
using Leadtools;
using Leadtools.Codecs;
using Leadtools.Ocr;
using Leadtools.Document.Writer;
public static void OcrRuntimeFileCallbackExample()
{
// This example assumes that some or all of the OCR runtime files are copied into "C:\MyDir" folder and simulates
// an environment where the runtime files can be obtained through helper methods HasResource and GetResourceStream.
// Create an OCR engine instance
IOcrEngine ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.LEAD);
// Install a OCR file runtime handler
ocrEngine.RuntimeFileCallback = MyRuntimeFileCallback;
// Startup the engine
ocrEngine.Startup(null, null, null,
null /* startupParameters is null*/);
// Perform OCR operation
ocrEngine.AutoRecognizeManager.Run(
@"C:\LEADTOOLS22\Resources\Images\ocr1.tif",
@"C:\LEADTOOLS22\Resources\Images\out.pdf",
DocumentFormat.Pdf,
null,
null);
// Shutdown
ocrEngine.Shutdown();
// Remove the handler
ocrEngine.RuntimeFileCallback = null;
// Dispose the engine
ocrEngine.Dispose();
}
private static RasterExceptionCode MyRuntimeFileCallback(IOcrEngine engine, OcrRuntimeFile runtimeFile)
{
// Called by the OCR engine for each runtime file operation
RasterExceptionCode result = RasterExceptionCode.Success;
// Check the operation:
switch (runtimeFile.Mode)
{
case OcrRuntimeFileMode.Exists:
Debug.WriteLine($"MyRuntimeFileCallback does '{runtimeFile.FileName}' exist");
// The engine is checking if a certain file exists, call our HasResource helper
if (!HasResource(runtimeFile.FileName))
result = RasterExceptionCode.FileNotFound;
break;
case OcrRuntimeFileMode.Open:
Debug.WriteLine($"MyRuntimeFileCallback open '{runtimeFile.FileName}'");
// The engine requested to open the file for reading, call our GetResourceStream helper
// and set the Stream property accordingly
runtimeFile.Stream = GetResourceStream(runtimeFile.FileName);
break;
case OcrRuntimeFileMode.Close:
Debug.WriteLine($"MyRuntimeFileCallback close '{runtimeFile.FileName}'");
// The engine requested to close the file after reading.
// Dispose our stream
runtimeFile.Stream.Dispose();
break;
}
return result;
}
private static bool HasResource(string resourceName)
{
// Do we have this resource?
// In our simulation, we will simply check if the file exist on disk
// In an Android application, this can check if a resource with this name was embedded
return System.IO.File.Exists(Path.Combine(@"C:\MyDir", resourceName));
}
private static Stream GetResourceStream(string resourceName)
{
// Get a stream that can read from resource
// In our simulation, we will simply check if the file exist on disk
// In an Android application, this can call the appropriate platform API to obtain
// a stream to the resource
return System.IO.File.OpenRead(Path.Combine(@"C:\MyDir", resourceName));
}
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import org.junit.*;
import org.junit.runner.JUnitCore;
import org.junit.runner.Result;
import org.junit.runner.notification.Failure;
import static org.junit.Assert.assertTrue;
import leadtools.*;
import leadtools.codecs.*;
import leadtools.document.writer.*;
import leadtools.ocr.*;
public void IOcrRuntimeFileCallbackExample() {
final String LEAD_VARS_IMAGES_DIR = "C:\\LEADTOOLS23\\Resources\\Images";
final String OCR_LEAD_RUNTIME_DIR = "C:\\LEADTOOLS23\\Bin\\Common\\OcrLEADRuntime";
// Create an OCR engine instance
OcrEngine ocrEngine = OcrEngineManager.createEngine(OcrEngineType.LEAD);
// Install a OCR file runtime handler
ocrEngine.setRuntimeFileCallback(MyRuntimeFileCallback);
// Startup the engine
ocrEngine.startup(null, null, null, OCR_LEAD_RUNTIME_DIR);
assertTrue(ocrEngine.isStarted());
// Perform OCR operation
ocrEngine.getAutoRecognizeManager().run(
combine(LEAD_VARS_IMAGES_DIR, "ocr1.tif"),
combine(LEAD_VARS_IMAGES_DIR, "out.pdf"),
DocumentFormat.PDF, null);
// Shutdown
ocrEngine.shutdown();
assertTrue(!ocrEngine.isStarted());
// Remove the handler
ocrEngine.setRuntimeFileCallback(null);
// Dispose the engine
ocrEngine.dispose();
System.out.println("OCR operation completed successfully");
}
OcrRuntimeFileCallbackListener MyRuntimeFileCallback = new OcrRuntimeFileCallbackListener() {
@Override
public RasterExceptionCode onCallback(OcrEngine arg0, OcrRuntimeFile runtimeFile) {
// Called by the OCR engine for each runtime file operation
RasterExceptionCode result = RasterExceptionCode.SUCCESS;
System.out.println(runtimeFile.getFileName());
// Check the operation:
switch (runtimeFile.getMode()) {
case EXISTS:
System.out.println("MyRuntimeFileCallback does " + runtimeFile.getFileName() + " exist");
// The engine is checking if a certain file exists, call our HasResource helper
if (!hasResource(runtimeFile.getFileName()))
result = RasterExceptionCode.FILE_NOT_FOUND;
break;
case OPEN:
System.out.println("MyRuntimeFileCallback open " + runtimeFile.getFileName());
// The engine requested to open the file for reading, call our GetResourceStream
// helper
// and set the Stream property accordingly
runtimeFile.setStream(getResourceStream(runtimeFile.getFileName()));
break;
case CLOSE:
System.out.println("MyRuntimeFileCallback close " + runtimeFile.getFileName());
// The engine requested to close the file after reading.
// Dispose our stream
runtimeFile.getStream().dispose();
break;
}
return result;
}
};
private boolean hasResource(String resourceName) {
final String OCR_LEAD_RUNTIME_DIR = "C:\\LEADTOOLS23\\Bin\\Common\\OcrLEADRuntime";
// Do we have this resource?
// In our simulation, we will simply check if the file exist on disk
// In an Android application, this can check if a resource with this name was
// embedded
File file = new File(combine(OCR_LEAD_RUNTIME_DIR, resourceName));
return file.exists();
}
private ILeadStream getResourceStream(String resourceName) {
final String OCR_LEAD_RUNTIME_DIR = "C:\\LEADTOOLS23\\Bin\\Common\\OcrLEADRuntime";
// Get a stream that can read from resource
// In our simulation, we will simply check if the file exist on disk
// In an Android application, this can call the appropriate platform API to
// obtain
// a stream to the resource
return LeadStreamFactory.create(combine(OCR_LEAD_RUNTIME_DIR, resourceName));
}
