Leadtools.Forms.Ocr Namespace > IOcrPageCollection Interface > AddPage Method : AddPage(Stream,OcrProgressCallback) Method |
IOcrPage AddPage( Stream stream, OcrProgressCallback callback )
'Declaration Overloads Function AddPage( _ ByVal stream As Stream, _ ByVal callback As OcrProgressCallback _ ) As IOcrPage
'Usage Dim instance As IOcrPageCollection Dim stream As Stream Dim callback As OcrProgressCallback Dim value As IOcrPage value = instance.AddPage(stream, callback)
IOcrPage AddPage( Stream stream, OcrProgressCallback callback )
- (LTOcrPage*)addPage:(LTLeadStream*)stream target:(id)target selector:(SEL)selector error:(NSError**)outError;
public OcrPage addPage(ILeadStream stream, OcrProgressListener callback)
function Leadtools.Forms.Ocr.IOcrPageCollection.AddPage(Stream,OcrProgressCallback)( stream , callback )
IOcrPage^ AddPage( Stream^ stream, OcrProgressCallback^ callback )
This method will load the first page from a raster image stored inside a .NET stream and adds it to the OCR document.
To add all or specific range of the pages of a multi-page image file stored in a .NET stream to the OCR document, use the AddPages(Stream stream, int imageFirstPageNumber, int imageLastPageNumber, OcrProgressCallback callback) method.
This method will add the page to the end of the collection if you already have pages in this IOcrPageCollection.
If you passed a Leadtools.Codecs.RasterCodecs object to the IOcrEngine.Startup, then this method will use the same Leadtools.Codecs.RasterCodecs object to load the raster image file. If you did not pass a Leadtools.Codecs.RasterCodecs object, the engine will create an instance the first time one of the add or export page methods is called.
The image file in stream can be any of the file formats supported by LEADTOOLS. For more information, refer to Summary of All Supported Image File Formats.
You can use the OcrProgressCallback to show the operation progress or to abort it. For more information and an example, refer to OcrProgressCallback.
The LEADTOOLS OCR engine supports pages of dots per inch (DPI) values of 150 and greater. If you try to add a page with a DPI of less than 150 then the engine might be able to recognize any data from this page.
Note, the LEADTOOLS Plus OCR engine does not support image size greater than A3 paper size (11.7 by 16.5 inches at 300 dpi). Attempting to add an image that has a size greater than A3 will result in an error. For document of size greater than the maximum allowed, you must first resize the image before adding it to the LEADTOOLS Plus OCR engine. The Professional and Advantage engines do not have a restriction on the image size.
Note: The value of the "Recognition.ShareOriginalImage" (only supported by the Advantage OCR engine) setting is not used when calling this method. The engine loads the image(s) and sets them in the pages internally. The original image reference can be obtained from the page using IOcrPage.GetRasterImage(OcrPageType.Original). Sharing the original image minimizes the memory used during OCR operations.
Imports Leadtools Imports Leadtools.Codecs Imports Leadtools.Forms.Ocr Imports Leadtools.Forms Imports Leadtools.Forms.DocumentWriters Imports Leadtools.WinForms Imports Leadtools.ImageProcessing.Core Imports Leadtools.Drawing Public Sub AddPageFromStreamExample() Dim tifFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.tif") Dim pdfFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.pdf") ' Load the TIF image into a memory stream Dim ms As New MemoryStream() Using fs As FileStream = File.OpenRead(tifFileName) Dim bufferSize As Integer = 1024 * 4 Dim buffer(bufferSize - 1) As Byte Dim bytes As Integer = 0 Do bytes = fs.Read(buffer, 0, bufferSize) If (bytes > 0) Then ms.Write(buffer, 0, bytes) End If Loop While (bytes > 0) End Using ' Reset the stream position ms.Position = 0 ' Create an instance of the engine Using ocrEngine As IOcrEngine = OcrEngineManager.CreateEngine(OcrEngineType.Advantage, False) ' Start the engine using default parameters ocrEngine.Startup(Nothing, Nothing, Nothing, LEAD_VARS.OcrAdvantageRuntimeDir) ' Create an OCR document Using ocrDocument As IOcrDocument = ocrEngine.DocumentManager.CreateDocument() ' Add the image ocrDocument.Pages.AddPage(ms, Nothing) ' We do not need the stream anymore ms.Dispose() ' Recognize ocrDocument.Pages.Recognize(Nothing) ' Save 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" Public Const OcrAdvantageRuntimeDir As String = "C:\LEADTOOLS 18\Bin\Common\OcrAdvantageRuntime" End Class
using Leadtools; using Leadtools.Codecs; using Leadtools.Forms.Ocr; using Leadtools.Forms.DocumentWriters; using Leadtools.Forms; using Leadtools.ImageProcessing.Core; public void AddPageFromStreamExample() { string tifFileName = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.tif"); string pdfFileName = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.pdf"); // Load the TIF image into a memory stream MemoryStream ms = new MemoryStream(); using (FileStream fs = File.OpenRead(tifFileName)) { const int bufferSize = 1024 * 4; byte[] buffer = new byte[bufferSize]; int bytes = 0; do { bytes = fs.Read(buffer, 0, bufferSize); if (bytes > 0) ms.Write(buffer, 0, bytes); } while (bytes > 0); } // Reset the stream position ms.Position = 0; // Create an instance of the engine using (IOcrEngine ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.Advantage, false)) { // Start the engine using default parameters ocrEngine.Startup(null, null, null, LEAD_VARS.OcrAdvantageRuntimeDir); // Create an OCR document using (IOcrDocument ocrDocument = ocrEngine.DocumentManager.CreateDocument()) { // Add the image ocrDocument.Pages.AddPage(ms, null); // We do not need the stream anymore ms.Dispose(); // Recognize ocrDocument.Pages.Recognize(null); // Save 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"; public const string OcrAdvantageRuntimeDir = @"C:\LEADTOOLS 18\Bin\Common\OcrAdvantageRuntime"; }