Get-EC2Ami.ps1

function Get-EC2Ami {
    [CmdletBinding()]
    param (
        [Parameter(Mandatory, Position = 0, ValueFromPipeline)]
        [SupportsWildcards()]
        [String] $ImageType,
 
        [Parameter(Mandatory, Position = 1)]
        [ArgumentCompleter( { (Get-AWSRegion).Region })]
        [String] $Region,
 
        [Parameter(Mandatory, Position = 2)]
        [String[]] $Owner
    )
 
    begin {
        $platformValues = [System.Collections.Generic.List[string]]::new()
    }
 
    process {
        $platformValues = $ImageType
 
        $filter = [Amazon.EC2.Model.Filter]@{
            Name   = "name"
            Values = $platformValues
        }
 
        Get-EC2Image -Owner $Owner -Region $Region -Filter $filter
    }
}