How to perform OCR for a PDF document in Azure environment
Step 1:
Create an Azure website project and refer the following assemblies in it:
- Syncfusion.Compression.Base.dll
- Syncfusion.Pdf.Base.dll
- Syncfusion.OCRProcessor.Base.dll
Step 2:
Add the Tesseract binaries and Tesseract data to the created project in separate folders as embedded resources.
The below screenshot shows the Tesseract binaries and Tesseract data added as separate files inside App_Data folder of the project.
Once the files are added, rebuild the project, then the added files can be found inside the “bin” folder of the project.
Step 3:
Now refer the Tesseract binaries and Tesseract data from the “bin” folder as shown in code snippet below.
C# :
using (OCRProcessor.OCRProcessor processor = new OCRProcessor.OCRProcessor(Server.MapPath("~/bin/App_Data/Tesseract_Binaries/")))
{
//Load a PDF document
Stream fileStream = File.OpenRead(Server.MapPath("~/bin/App_Data/input.pdf"));
PdfLoadedDocument lDoc = new PdfLoadedDocument(fileStream);
//Set OCR language and perform OCR
processor.Settings.Language = "eng";
processor.PerformOCR(lDoc, Server.MapPath("~/bin/App_Data/Tesseract_Data/"));
//Save and close the document
lDoc.Save("Output.pdf", this.Response, HttpReadType.Save);
lDoc.Close(true);
}
VB:
Using processor As New OCRProcessor.OCRProcessor(Server.MapPath("~/bin/App_Data/Tesseract_Binaries/"))
'Load a PDF document
Dim fileStream As Stream = File.OpenRead(Server.MapPath("~/bin/App_Data/input.pdf"))
Dim lDoc As New PdfLoadedDocument(fileStream)
'Set OCR language and perform OCR
processor.Settings.Language = "eng"
processor.PerformOCR(lDoc, Server.MapPath("~/bin/App_Data/Tesseract_Data/"))
'Save and close the document
lDoc.Save("Output.pdf", Me.Response, HttpReadType.Save)
lDoc.Close(True)
End Using
Now when this project is published in Azure it will directly refer the Tesseract binaries and Tesseract data from” bin” folder and OCR process can be performed with this code snippet.
