ByteScout Text Recognition SDK – PowerShell – Use Image Preprocessing Filters

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ByteScout Text Recognition SDK – PowerShell – Use Image Preprocessing Filters

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ByteScout-Text-Recognition-SDK-PowerShell-Use-Image-Preprocessing-Filters.pdf

How to use image preprocessing filters in PowerShell with ByteScout Text Recognition SDK

This tutorial will show how to use image preprocessing filters in PowerShell

These source code samples are listed and grouped by their programming language and functions they use. ByteScout Text Recognition SDK: the SDK designed to help developers in quick implementation of high quality OCR text recognition from scanned images and pdf. It can use image preprocessing filters in PowerShell.

The SDK samples like this one below explain how to quickly make your application do use image preprocessing filters in PowerShell with the help of ByteScout Text Recognition SDK. This PowerShell sample code is all you need for your app. Just copy and paste the code, add references (if needs to) and you are all set! Code testing will allow the function to be tested and work properly with your data.

Free trial version of ByteScout Text Recognition SDK is available on our website. Documentation and source code samples are included.

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ImagePreprocessingFilters.ps1

      # Add reference to ByteScout.TextRecognition.dll assembly
Add-Type -Path "c:\Program Files\ByteScout Text Recognition SDK\net40\ByteScout.TextRecognition.dll"

$InputDocument = "..\..\skewed.png"
$OutputDocument = ".\result.txt"

# Create and activate TextRecognizer instance
$textRecognizer = New-Object ByteScout.TextRecognition.TextRecognizer
$textRecognizer.RegistrationName = "demo"
$textRecognizer.RegistrationKey = "demo"

try {
    # Load document (image or PDF)
    $textRecognizer.LoadDocument($InputDocument)

    # Set the location of OCR language data files
    $textRecognizer.OCRLanguageDataFolder = "c:\Program Files\ByteScout Text Recognition SDK\ocrdata_best\"

    # Set OCR language.
    # "eng" for english, "deu" for German, "fra" for French, "spa" for Spanish, etc. - according to files in "ocrdata" folder
    # Find more language files at https://github.com/bytescout/ocrdata
    $textRecognizer.OCRLanguage = "eng"


    # Add deskew filter that automatically rotates the image to make the text horizontal.
    # Note, it analyzes the left edge of scanned text. Any dark artifacts may prevent 
    # the correct angle detection.
    $textRecognizer.ImagePreprocessingFilters.AddDeskew()

    # Other filters that may be useful to improve recognition
    # (note, the filters are applied in the order they were added):

    # Improve image contrast.
    #$textRecognizer.ImagePreprocessingFilters.AddContrast()

    # Apply gamma correction.
    #$textRecognizer.ImagePreprocessingFilters.AddGammaCorrection()

    # Apply median filter. Helps to remove noise.
    #$textRecognizer.ImagePreprocessingFilters.AddMedian()

    # Apply dilate filter. Helps to cure symbols erosion.
    #$textRecognizer.ImagePreprocessingFilters.AddDilate()

    # Lines removers. Removing borders of some tables may improve the recognition.
    #$textRecognizer.ImagePreprocessingFilters.AddHorizontalLinesRemover()
    #$textRecognizer.ImagePreprocessingFilters.AddVerticalLinesRemover()


    # Recognize text from all pages and save it to file
    $textRecognizer.SaveText($OutputDocument)

    # Open the result file in default associated application (for demo purposes)
    & $OutputDocument
}
catch {
    # Display exception
    Write-Host $_.Exception.Message
}

$textRecognizer.Dispose()

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run.bat

      @echo off

powershell -NoProfile -ExecutionPolicy Bypass -Command "& .\ImagePreprocessingFilters.ps1"
echo Script finished with errorlevel=%errorlevel%

pause