using namespace Windows.Storage using namespace Windows.Graphics.Imaging using namespace System.IO.WindowsRuntimeStreamExtensions using namespace System.IO.WindowsRuntimeStreamExtensions using namespace System.Text using namespace System.Text.Json

Add the WinRT assembly, and load the appropriate WinRT types

Add-Type -AssemblyName System.Runtime.WindowsRuntime Add-Type -AssemblyName System.Runtime.Serialization

$null = [Windows.Storage.StorageFile, Windows.Storage, ContentType = WindowsRuntime]$null = [Windows.Media.Ocr.OcrEngine, Windows.Foundation, ContentType = WindowsRuntime] $null = [Windows.Foundation.IAsyncOperation`1, Windows.Foundation, ContentType = WindowsRuntime]$null = [Windows.Graphics.Imaging.SoftwareBitmap, Windows.Foundation, ContentType = WindowsRuntime] $null = [Windows.Storage.Streams.RandomAccessStream, Windows.Storage.Streams, ContentType = WindowsRuntime]

[Windows.Media.Ocr.OcrEngine]::AvailableRecognizerLanguages

$ocrEngine = [Windows.Media.Ocr.OcrEngine]::TryCreateFromLanguage("en")

PowerShell doesn't have built-in support for Async operations,

but all the WinRT methods are Async.

This function wraps a way to call those methods, and wait for their results.

getAwaiterBaseMethod = [WindowsRuntimeSystemExtensions].GetMember('GetAwaiter'). Where({ PSItem.GetParameters()[0].ParameterType.Name -eq 'IAsyncOperation`1' }, 'First')[0]

Function Await { param($AsyncTask,$ResultType)

$getAwaiterBaseMethod.
    MakeGenericMethod($ResultType).
    Invoke($null, @($AsyncTask)).
    GetResult()

}

$http = [System.Net.HttpListener]::new()

Hostname and port to listen on

$http.Prefixes.Add("http://+:80/")

Start the Http Server

$http.Start()

Add-Type -AssemblyName System.Web

Log ready message to terminal

if (http.IsListening) { write-host "HTTP Server Ready! " -f 'black' -b 'gre' write-host "($http.Prefixes)" -f 'y' }

while (http.IsListening) { # Get Request Url # When a request is made in a web browser the GetContext() method will return a request object # Our route examples below will use the request object properties to decide how to respond context = $http.GetContext() if ($context.Request.HttpMethod -eq 'GET') { $Context.Response.ContentType = "text/html"$buffer = [System.Text.Encoding]::UTF8.GetBytes("<input type=file onchange=""fetch('', {method: 'POST', body: this.files[0]}).then(r=>r.json()).then(console.log)"">") $context.Response.OutputStream.Write($buffer, 0, $buffer.Length)$Context.Response.Close() }

if ($context.Request.HttpMethod -eq 'POST') {

    # We can log the request to the terminal
    write-host "$($context.Request.UserHostAddress)  =>  $($context.Request.Url)" -f 'mag'
    $memStream = [System.IO.MemoryStream]::new()
    $context.Request.InputStream.CopyTo($memStream)

    $params = @{
        AsyncTask  = [BitmapDecoder]::CreateAsync([System.IO.WindowsRuntimeStreamExtensions]::AsRandomAccessStream($memStream))
        ResultType = [BitmapDecoder]
    }
    $bitmapDecoder = Await @params


    $params = @{ 
        AsyncTask = $bitmapDecoder.GetSoftwareBitmapAsync()
        ResultType = [SoftwareBitmap]
    }
    $softwareBitmap = Await @params

    # Run the OCR
    $result = Await $ocrEngine.RecognizeAsync($softwareBitmap) ([Windows.Media.Ocr.OcrResult])

    $Context.Response.ContentType = "application/json"
    $serialized = $result | ConvertTo-Json -Depth 5 -Compress
    $buffer = [System.Text.Encoding]::UTF8.GetBytes($serialized)
    $context.Response.OutputStream.Write($buffer, 0, $buffer.Length)
    $Context.Response.Close()
}

}