Resize Images using Powershell

resize.ps1

## Usage
# cd thebasepath
# .\resize.ps1
function Resize-Image
{
    <#
    .EXAMPLE
        Resize-Image -InputFile "C:\kitten.jpg" -Scale 30 -OutputFile "C:\kitten2.jpg"

        Resize the image to 30% of its original size and save it to a new file.
    #>
    Param(
        [Parameter(Mandatory=$true)][string]$InputFile, 
        [Parameter(Mandatory=$true)][string]$OutputFile, 
        [Parameter(Mandatory=$true)][int32]$Scale)

    # Add System.Drawing assembly
    Add-Type -AssemblyName System.Drawing

    # Open image file
    $img = [System.Drawing.Image]::FromFile((Get-Item $InputFile))

    # Define new resolution
    [int32]$new_width = $img.Width * ($Scale / 100)
    [int32]$new_height = $img.Height * ($Scale / 100)

    # Create empty canvas for the new image
    $img2 = New-Object System.Drawing.Bitmap($new_width, $new_height)

    # Draw new image on the empty canvas
    $graph = [System.Drawing.Graphics]::FromImage($img2)
    $graph.DrawImage($img, 0, 0, $new_width, $new_height)

    $graph.Dispose()
    $img.Dispose()
    $img2.Save($OutputFile)
    $img2.Dispose()
}

$allfiles = Get-ChildItem -Recurse | 
    Where { $_.PsIsContainer -ieq $false } |
    Where { $_.Name.Contains("jpg") -or $_.Name.Contains("jpeg") }

foreach($file in $allfiles) {
    $saveTarget = $file.FullName
    $tempTarget = $file.FullName + ".temp"

    Write-Host "[Info] processor - Processing $saveTarget"

    Resize-Image -InputFile $saveTarget -OutputFile $tempTarget -Scale 50

    Write-Host "[Info] processor - Replacing file $saveTarget"
    Remove-Item $saveTarget -Force
    Move-Item $tempTarget $saveTarget
    Write-Host "[Info] processor - Sucessfully processed $saveTarget"
}