Scanned PDF To Text | VB.NETByteScout PDF Extractor SDK

Scanned PDF To Text | VB.NET


Imports Bytescout.PDFExtractor

' This example demonstrates the use of Optical Character Recognition (OCR) to extract text 
' from scanned PDF documents and raster images.

' To make OCR work you should add the following references to your project:
' "Bytescout.PDFExtractor.dll", "Bytescout.PDFExtractor.OCRExtension.dll".

Class Program

    Friend Shared Sub Main(args As String())

        ' Create Bytescout.PDFExtractor.TextExtractor instance
        Dim extractor As New TextExtractor()
        extractor.RegistrationName = "demo"
        extractor.RegistrationKey = "demo"

        ' Load sample PDF document

        ' Enable Optical Character Recognition (OCR)
        ' in .Auto mode (SDK automatically checks if needs to use OCR or not)
        extractor.OCRMode = OCRMode.Auto

        ' Set the location of OCR language data files
        extractor.OCRLanguageDataFolder = "c:\Program Files\Bytescout PDF Extractor SDK\ocrdata_best"

        ' Set OCR language
        extractor.OCRLanguage = "eng"  ' "eng" for english, "deu" for German, "fra" for French, "spa" for Spanish etc - according to files in "ocrdata" folder
        ' Find more language files at

        ' Set PDF document rendering resolution
        extractor.OCRResolution = 300

        ' You can also apply various preprocessing filters
        ' to improve the recognition on low-quality scans.

        ' Automatically deskew skewed scans

        ' Remove vertical or horizontal lines (sometimes helps to avoid OCR engine's page segmentation errors)

        ' Repair broken letters

        ' Remove noise

        ' Apply Gamma Correction

        ' Add Contrast
        ' extractor.OCRImagePreprocessingFilters.AddContrast(20)

        ' (!) You can use new OCRAnalyzer class to find an optimal set of image preprocessing 
        ' filters for your specific document.
        ' See "OCR Analyser" example.

        ' Save extracted text to file

        ' Cleanup

        ' Open output file in default associated application

    End Sub

End Class