Invoke-ExtractIcon.psm1

function Invoke-ExtractIcon {
    [CmdletBinding(SupportsShouldProcess)]
    Param(
        [Parameter(Position = 0, Mandatory,HelpMessage = "Specify the path to the file.")]
        [ValidateScript({Test-Path $_})]
        [string]$Path,

        [Parameter(HelpMessage = "Specify the folder to save the file.")]
        [ValidateScript({Test-Path $_})]
        [string]$Destination = ".",

        [parameter(HelpMessage = "Specify an alternate base name for the new image file. Otherwise, the source name will be used.")]
        [ValidateNotNullOrEmpty()]
        [string]$Name,

        [Parameter(HelpMessage = "What format do you want to use? The default is png.")]
        [ValidateSet("ico","bmp","png","jpg","gif")]
        [string]$Format = "png"
    )
    # inspired by https://community.spiceworks.com/topic/592770-extract-icon-from-exe-powershell

    if ($PSVersionTable.PSVersion -lt [System.Version]'5.1') {
        Write-Warning "PowerShell version $($PSVersionTable.PSVersion.ToString()) is not supported."
        return
    }

    Write-Verbose "Starting $($MyInvocation.MyCommand)"

    try {
        Add-Type -AssemblyName System.Drawing -ErrorAction Stop
    } catch {
        Write-Warning "Failed to import System.Drawing"
        Throw $_
    }

    switch ($format) {
        "ico" {$ImageFormat = "icon"}
        "bmp" {$ImageFormat = "Bmp"}
        "png" {$ImageFormat = "Png"}
        "jpg" {$ImageFormat = "Jpeg"}
        "gif" {$ImageFormat = "Gif"}
    }

    $file = Get-Item $path
    Write-Verbose "Processing $($file.fullname)"
    #convert destination to file system path
    $Destination = Convert-Path -Path $Destination

    if ($Name) {
        $base = $Name
    } else {
        $base = $file.BaseName
    }

    #construct the image file name
    $out = Join-Path -Path $Destination -ChildPath "$base.$format"

    Write-Verbose "Extracting $ImageFormat image to $out"
    $ico =  [System.Drawing.Icon]::ExtractAssociatedIcon($file.FullName)

    if ($ico) {
        #WhatIf (target, action)
        if ($PSCmdlet.ShouldProcess($out, "Extract icon")) {
            $ico.ToBitmap().Save($Out,$Imageformat)
            Get-Item -path $out
        }
    } else {
        #this should probably never get called
        Write-Warning "No associated icon image found in $($file.fullname)"
    }

    Write-Verbose "Ending $($MyInvocation.MyCommand)"
}