Merge two Images in same folder

Merge-Image.ps1

#
# Usage : .\Merge-Image.ps1 .\test*.png .\mergeImages\
#

$fileList = Get-ChildItem $args[0]
for ($i = 0; $i -lt $fileList.count; $i = $i + 2) {
    # Add System.Drawing assembly
    Add-Type -AssemblyName System.Drawing
    $firstImage = [System.Drawing.Image]::FromFile((Get-Item $fileList[$i]))
    if (($i + 1) -lt $fileList.count) {
        $secondImage = [System.Drawing.Image]::FromFile((Get-Item $fileList[$i + 1]))
    }
    else {
        # make empty Image
        $secondImage = New-Object System.Drawing.Bitmap($firstImage.width, $firstImage.height)
    }

    [Int]$new_width = [Int]$firstImage.Width
    [Int]$new_height = [Int]$($firstImage.height + $secondImage.height)

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

    # Draw new image on the empty canvas
    $graph = [System.Drawing.Graphics]::FromImage($newImage)
    $graph.DrawImage($secondImage, 0, [Int]$firstImage.height, [Int]$secondImage.Width, [Int]$secondImage.height)
    $graph.DrawImage($firstImage, 0, 0, [Int]$firstImage.Width, [Int]$firstImage.height)

    # Create window to display the new image
    if ($Display) {
        Add-Type -AssemblyName System.Windows.Forms
        $win = New-Object Windows.Forms.Form
        $box = New-Object Windows.Forms.PictureBox
        $box.Width = $new_width
        $box.Height = $new_height
        $box.Image = $newImage
        $win.Controls.Add($box)
        $win.AutoSize = $true
        $win.ShowDialog()
    }

    $newFileName = Split-Path -Path (get-Item $fileList[$i]).FullName -Leaf
    $newFileName = $newFileName -replace ".png", "_marge_$i.png"
    $newFileName = "$($(get-Item $args[1]).fullname)\$newFileName"
    echo $newFileName
    $newImage.Save($newFileName)
}