Convert Teams background files for v2

# Review required modules and connection steps before running.
# Connect to Microsoft Graph or Exchange Online as needed for this script.

Function Resize-Image() {
    [CmdLetBinding(
        SupportsShouldProcess=$true,
        PositionalBinding=$false,
        ConfirmImpact="Medium",
        DefaultParameterSetName="Absolute"
    )]
    Param (
        [Parameter(Mandatory=$True)]
        [ValidateScript({
            $_ | ForEach-Object {
                Test-Path $_
            }
        })][String[]]$ImagePath,
        [Parameter(Mandatory=$False)][Switch]$MaintainRatio,
        [Parameter(Mandatory=$False, ParameterSetName="Absolute")][Int]$Height,
        [Parameter(Mandatory=$False, ParameterSetName="Absolute")][Int]$Width,
        [Parameter(Mandatory=$False, ParameterSetName="Percent")][Double]$Percentage,
        [Parameter(Mandatory=$False)][System.Drawing.Drawing2D.SmoothingMode]$SmoothingMode = "HighQuality",
        [Parameter(Mandatory=$False)][System.Drawing.Drawing2D.InterpolationMode]$InterpolationMode = "HighQualityBicubic",
        [Parameter(Mandatory=$False)][System.Drawing.Drawing2D.PixelOffsetMode]$PixelOffsetMode = "HighQuality",
        [Parameter(Mandatory=$False)][String]$NameModifier = "resized"
    )
    Begin {
        If ($Width -and $Height -and $MaintainRatio) {
            Throw "Absolute Width and Height cannot be given with the MaintainRatio parameter."
        }
 
        If (($Width -xor $Height) -and (-not $MaintainRatio)) {
            Throw "MaintainRatio must be set with incomplete size parameters (Missing height or width without MaintainRatio)"
        }
 
        If ($Percentage -and $MaintainRatio) {
            Write-Warning "The MaintainRatio flag while using the Percentage parameter does nothing"
        }
    }
    Process {
        Add-Type -AssemblyName 'System.Drawing'
        ForEach ($Image in $ImagePath) {
            $Path = (Resolve-Path $Image).Path
            $Dot = $Path.LastIndexOf(".")
 
            #Add name modifier (OriginalName_{$NameModifier}.jpg)
            $OutputPath = $Path.Substring(0,$Dot) + "_" + $NameModifier + $Path.Substring($Dot,$Path.Length - $Dot)
 
            $OldImage = New-Object -TypeName System.Drawing.Bitmap -ArgumentList $Path
            # Grab these for use in calculations below.
            $OldHeight = $OldImage.Height
            $OldWidth = $OldImage.Width
 
            If ($MaintainRatio) {
                $OldHeight = $OldImage.Height
                $OldWidth = $OldImage.Width
                If ($Height) {
                    $Width = $OldWidth / $OldHeight * $Height
                }
                If ($Width) {
                    $Height = $OldHeight / $OldWidth * $Width
                }
            }
 
            If ($Percentage) {
                $Product = ($Percentage / 100)
                $Height = $OldHeight * $Product
                $Width = $OldWidth * $Product
            }
 
            $Bitmap = New-Object -TypeName System.Drawing.Bitmap -ArgumentList $Width, $Height
            $NewImage = [System.Drawing.Graphics]::FromImage($Bitmap)
 
            #Retrieving the best quality possible
            $NewImage.SmoothingMode = $SmoothingMode
            $NewImage.InterpolationMode = $InterpolationMode
            $NewImage.PixelOffsetMode = $PixelOffsetMode
            $NewImage.DrawImage($OldImage, $(New-Object -TypeName System.Drawing.Rectangle -ArgumentList 0, 0, $Width, $Height))
 
            If ($PSCmdlet.ShouldProcess("Resized image based on $Path", "save to $OutputPath")) {
                $Bitmap.Save($OutputPath)
            }
 
            $Bitmap.Dispose()
            $NewImage.Dispose()
            $OldImage.Dispose()
        }
    }
}
 
# Start of processing to convert Teams background images
 
# First, identify the target directory where Teams V2 stores its background images. Each
# image has two files - a full version and a thumbnail.
$TargetDirectory = ($Env:appdata -Split("\\Roaming"))[0] + "\Local\Packages\MSTeams_8wekyb3d8bbwe\LocalCache\Microsoft\MSTeams\Backgrounds\Uploads"
# Now find the folder where Teams V1 stored its background files
$TeamsV1Directory = $Env:appdata + "\Microsoft\Teams\Backgrounds\Uploads"
 
# Check that the two folders are available
If (!(Test-Path -Path $TargetDirectory)) {
    New-Item -Path $TargetDirectory -ItemType Directory
}
 
If (!(Test-Path $TeamsV1Directory)) {
    Write-Host ("The Teams V1 folder for background images is not on this PC - exiting!" -f $TeamsV1Directory)
    break
}
 
# Get the set of files that we can convert
Set-Location -Path $TeamsV1Directory
[array]$Files = Get-ChildItem "*.jpg" | Select-Object -ExpandProperty Name
[int]$i =0
# If we can find some JPG files to convert, go ahead and create new files
If ($Files) {
 # Remove thumb nails and only process full definition files
 $Files = $Files | Where-Object {$_ -notlike "*_thumb.jpg*"}
 ForEach ($File in $Files) {
    Write-Host ("Processing {0}..." -f $File)
    $Name = $File.Split(".")[0]
    $OutputFile = $Name + "_resized.jpg"
    # Create 1920x1080 version of file
    Resize-image -ImagePath $File -height 1080 -Width 1920
    If ($OutputFile) {
        $Guid = New-Guid
        $FullFileName = ("{0}.jpg" -f $Guid)
        Rename-Item $OutputFile $FullFileName
    }
    # Now create the thumbnail image
    $OutputFile = $Name + "_resized.jpg"
    Resize-image -ImagePath $File -height 158 -Width 220
    If ($OutputFile) {
        $ThumbFileName = ("{0}_thumb.jpg" -f $Guid)
        Rename-Item $OutputFile $ThumbFileName
    }
    $CopyFiles = ("{0}*.jpg" -f $Guid)
    # Copy files to the Teams V2 folder and clean up by removing them from the V1 folder
    Copy-Item $CopyFiles $TargetDirectory
    Remove-Item $CopyFiles
    $i++
 } # End ForEach Files
} # End if Files
Write-Host ("All done. {0} files processed and copied to the Teams V2 folder. You should be able to use these files as background images in Teams V2 meetings" -f $i)
Set-Location -Path $TargetDirectory
Get-ChildItem "*.jpg"
Set-Location -Path "C:\"