Invert Color Of An Image Using Powershell

Invert-Image.ps1

#
# Usage : .\Invert-Image.ps1 .\test*.png
#
[System.Reflection.Assembly]::LoadWithPartialName("System.Drawing") | Out-Null
Get-ChildItem $args[0] | ForEach-Object {
    $image = New-Object System.Drawing.Bitmap($_.fullname)
    for ($y = 0; $y -lt $image.Height; $y++) {
        for ($x = 0; $x -lt $image.Width; $x++) {
            $pixelColor = $image.GetPixel($x, $y)
            $varR = 255 - $pixelColor.R
            $varG = 255 - $pixelColor.G
            $varB = 255 - $pixelColor.B
            $image.SetPixel($x, $y, [System.Drawing.Color]::FromArgb($varR, $varG, $varB))
        }
    }
    $image.MakeTransparent($image.GetPixel(10, 10))    
    $newFileName = $_.FullName -replace ".png", "-2.png"
    $image.Save($newFileName)
}