Windows Explorer Bildkompression programmatisch ansprechen

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\*\shell\ImageResizer]
@="Bilder verkleinern"  

[HKEY_CLASSES_ROOT\*\shell\ImageResizer\command]
@="\"C:\\Windows\\System32\\WindowsPowerShell\\v1.0\\powershell.exe\" -ExecutionPolicy ByPass -Noninteractive -NoProfile -File \"C:\\skripte\\resizer.ps1\" \"%1\""  

param(
    [parameter(mandatory=$true)][string]$pImagePath
)
function Resize-Image{
    param(
        [parameter(mandatory=$true,ValueFromPipeline=$true)][alias("FullName")][string[]]$images,  
        [parameter(mandatory=$true)][string]$OutPath,
        [parameter(mandatory=$true)][int32]$NewWidth,
        [parameter(mandatory=$true)][int32]$NewHeight,
        [switch]$Passthru,
        [switch]$DownSizeOnly,
        [switch]$AppendSizeToFilename
    )
    begin{
        Add-Type -AssemblyName System.Drawing
        $resizedCollection = @()
    }
    process{
        $images | %{
            $ext = [System.IO.Path]::GetExtension($_)
            $basename = [System.IO.Path]::GetFileNameWithoutExtension($_)
            
            if ($ext -match "bmp$|jpe?g$|gif$|tiff?$|png$"){  
                Try{
                    $img = [System.Drawing.Bitmap]::FromFile($_)
                    $percentWidth = $newWidth / $img.Width
                    $percentHeight = $newHeight / $img.Height
                    if ($percentWidth -lt $percentHeight){$ratio = $percentWidth}else{$ratio = $percentHeight}
                    [int32]$nWidth = $img.Width * $ratio
                    [int32]$nHeight = $img.Height * $ratio
                    if ($DownSizeOnly.IsPresent -and $ratio -ge 1){
                        copy-item $_ $outPath
                        return
                    }
                    $newImg = new-Object System.Drawing.Bitmap($nWidth,$nHeight)
                    ([System.Drawing.Graphics]::FromImage($newImg)).DrawImage($img,0,0,$newImg.Width,$newImg.Height)
                    $newImagePath = ""  
                    if($AppendSizeToFilename.IsPresent){
                        $newImagePath = "$outPath\$($basename)_$($nWidth)x$($nHeight)$ext"  
                    }else{
                        $newImagePath = "$outPath\$basename$ext"  
                    }
                    if(!(test-Path $outPath)){md $outPath}
                    $newImg.Save($newImagePath,$img.RawFormat)
                    $resizedCollection += $newImagePath
                    # write-host "Resized Image '$_' to '$newImagePath'" -ForegroundColor Green 
                }catch{
                    Write-Error -Message $_.Exception.Message
                }
            }else{
                Write-Error -Message "Das Bild '$_' hat kein unterstütztes Format. Folgende Formate werden unterstützt: bmp|jpg|gif|tif|png"  
            }
        }
    }
    end{
        $img.Dispose()
        $newImg.Dispose()
        [System.GC]::Collect()
        if($passthru.IsPresent){return $resizedCollection}
    }
}

Resize-Image -images $pImagePath -OutPath ([System.IO.Path]::GetDirectoryName($pImagePath)) -NewWidth 1280 -NewHeight 1024 -AppendSizeToFilename