ConvertICO2Image.psm1

<#
	.SYNOPSIS
		Converts a given ICO file to a either a PNG, JPG, BMP or Tiff File
	
	.PARAMETER files
		The directory where your .ico file is stored (defaults to the Current Working Directory)

	.PARAMETER Formats
		The format you would like to convert to. Can input more than one format if you want multiple copies.
	
	.EXAMPLE
		PS C:\> Convert-ICO2Image

	.EXAMPLE
		PS C:\> Convert-ICO2Image -files c:\ico_conversion -Format Png

	.EXAMPLE
		PS C:\> Convert-ICO2Image -files "C:\ico_conversion" -Formats Bmp,Jpeg,Png,Tiff,Gif

#>
function Convert-ICO2Image
{
	[CmdletBinding()]
	param
	(
		[Parameter(Mandatory = $false)]
		$files = (Get-Item .\).FullName,
		[Parameter(Mandatory = $false)]
		[ValidateNotNull()]
		[ValidateSet('Png','Jpeg','Bmp','Tiff','Gif')]
		[string[]]$Formats = 'Png'
	)
	begin
	{
		Add-Type -AssemblyName system.drawing
	}
	process
	{
		foreach ($Format in $Formats)
		{
			$files = Get-ChildItem $files -Filter *.ico -file -Recurse |
			foreach-object {
				$Source = $_.FullName
				$test = [System.IO.Path]::GetDirectoryName($source)
				$base = $_.BaseName + ".$Format"
				$basedir = $test + "\" + $base
				$imageFormat = "System.Drawing.Imaging.ImageFormat" -as [type]
				$image = [drawing.image]::FromFile($Source)
				
				# Create a new image
				$NewImage = [System.Drawing.Bitmap]::new($Image.Width, $Image.Height)
				$NewImage.SetResolution($Image.HorizontalResolution, $Image.VerticalResolution)
				
				# Add graphics based on the new image
				$Graphics = [System.Drawing.Graphics]::FromImage($NewImage)
				$Graphics.DrawImageUnscaled($image, 0, 0) # Add the contents of $image
				
				# Now save the $NewImage 
				$NewImage.Save($basedir, $imageFormat::$Format)
			}
		}
	}
}