Invoke-AutoCrop.ps1

#Requires -Modules ThreadJob
using namespace System.Collections.Generic

function Invoke-AutoCrop {
    <#
    .SYNOPSIS
    Uses the Python AutoCrop tool to crop images down to faces found in the image.
    
    .DESCRIPTION
    Using the AutoCrop tool, images are stripped down to just detected faces and either saved over the original
    image(s), or into a new location.

    Be aware that this cropping is destructive. Copies should be made prior to cropping if originals need
    to be kept intact, as AutoCrop neglects to save the originals.
    
    .PARAMETER Path
    Enter the path to the folder which holds the images to crop.
    
    .PARAMETER Destination
    Enter a destination to save the cropped images to. If none is specified, the images will be overwritten in-place.
    
    .PARAMETER RejectPath
    Enter a destination to move images which do not contain faces to. if none is specified, this defaults to the same
    directory as -Destination.
    
    .PARAMETER CroppedSizeRatio
    The percentage of the image that contains a face. For example, if the face takes up a third of the image size,
    you would enter -CroppedSizeRatio 33
    
    .PARAMETER Width
    The final width of the cropped images in pixels. Default is 500px.
    
    .PARAMETER Height
    The final height of the cropped images in pixels. Defaults to 500px.
    
    .PARAMETER PadTop
    Weight the placement upwards. Default is 50, use a higher number to move the cropped region upwards.
    
    .PARAMETER PadBottom
    Weight the placement downwards. Default is 50, use a higher number to move the cropped region downwards.
    
    .PARAMETER PadLeft
    Weight the placement leftwards. Default is 50, use a higher number to move the cropped region leftwards.
    
    .PARAMETER PadRight
    Weight the placement rightwards. Default is 50, use a higher number to move the cropped region rightwards.
    
    .EXAMPLE
    Invoke-AutoCrop -Path . -Destination .\Cropped
    
    .NOTES
    This function assumes the AutoCrop utility has been installed already. AutoCrop is dependent on Python 3.
    After installing Python 3, execute the following command to install AutoCrop.

        PS> pip install autocrop

    If Python is installed but AutoCrop is not, this command will first attempt to install it.
    #>
    
    [CmdletBinding()]
    param(
        [Parameter(Mandatory, ValueFromPipeline, ValueFromPipelineByPropertyName)]
        [Alias('InputFolder')]
        [string[]]
        $Path,

        [Parameter()]
        [Alias('OutputFolder')]
        [string]
        $Destination,

        [Parameter()]
        [Alias('RejectFolder')]
        [string]
        $RejectPath,

        [Parameter()]
        [Alias('FacePercent')]
        [int]
        $CroppedSizeRatio = 10,

        [Parameter()]
        [int]
        $Width,

        [Parameter()]
        [int]
        $Height,

        [Parameter()]
        [int]
        $PadTop,

        [Parameter()]
        [int]
        $PadBottom,

        [Parameter()]
        [int]
        $PadLeft,

        [Parameter()]
        [int]
        $PadRight
    )
    begin {
        if (-not (Get-Command -Name autocrop -ErrorAction SilentlyContinue)) {
            if (Get-Command -Name pip -ErrorAction SilentlyContinue) {
                Write-Warning "AutoCrop utility is not installed. Attempting to install."
                pip install autocrop
            }
            else {
                $Params = @{
                    ErrorAction       = 'Stop'
                    Message           = 'Python 3 install could not be located. Please ensure Python 3 is installed and available on $env:Path'
                    Category          = 'NotInstalled'
                    ErrorId           = 'Invoke-AutoCrop.Python3.NotInstalled' 
                    RecommendedAction = 'Install Python 3'
                }
                Write-Error @Params
            }
        }
        
        if ($Destination) {
            $Destination = if (Test-Path -Path $Destination) {
                Get-Item -Path $Destination
            }
            else {
                New-Item -Path $Destination -ItemType Directory
            }
        }

        if ($RejectPath) {
            $RejectPath = if (Test-Path -Path $RejectPath) {
                Get-Item -Path $RejectPath
            }
            else {
                New-Item -Path $RejectPath -ItemType Directory
            }
        }

        $JobList = [List[object]]::new()
    }
    process {
        if ($MyInvocation.ExpectingInput) {
            $Path = , $Path
        }
        foreach ($InputPath in $Path) {
            $InputPath = Get-Item -Path $InputPath
            $Job = Start-ThreadJob -ScriptBlock {
                param(
                    $Path, $Destination, $RejectPath, 
                    $CroppedSizeRatio, $Width, $Height, 
                    $PadTop, $PadBottom, $PadLeft, $PadRight
                )

                Start-Process -FilePath 'autocrop' -Wait -NoNewWindow -ArgumentList @(
                    '-i "{0}"' -f $Path 
                    '-o "{0}"' -f $Destination 
                    "--facePercent $CroppedSizeRatio"
                    switch ($true) {
                        { $RejectPath } {
                            '-r "{0}"' -f $RejectPath
                        }
                        { $Width } {
                            "-w $Width"
                        }
                        { $Height } {
                            "-h $Height"
                        }
                        { $PadTop } {
                            "--padUp $PadTop"
                        }
                        { $PadBottom } {
                            "--padDown $PadBottom"
                        }
                        { $PadLeft } {
                            "--padLeft $PadLeft"
                        }
                        { $PadRight } {
                            "--padRight $PadRight"
                        }
                    }
                )
            } -ArgumentList @(
                $InputPath
                $Destination
                $RejectPath
                $CroppedSizeRatio
                $Width
                $Height
                $PadTop
                $PadBottom
                $PadLeft
                $PadRight
            )

            $JobList.Add(
                [PSCustomObject]@{
                    Path = $InputPath
                    Job  = $Job
                }
            )
        }
    }
    end {
        while ($JobList.State -contains 'Running') {
            $CompletedCount = $JobList.Where{ $_.State -eq 'Completed' }.Count
            $TotalCount = $JobList.Count
            Write-Progress -Activity "Processing Images..." -Status "$CompletedCount of $TotalCount folders processed." -PercentComplete ($CompletedCount / $TotalCount)
        }

        foreach ($Job in $JobList) {
            $Output = $Job | Receive-Job
            $Pattern = @(
                '(?<FileCount>[0-9]+) input files'
                '(?<CroppedFaces>[0-9]+) faces cropped'
                '(?<RejectedFiles>[0-9]+) rejected'
            ) -join ', '

            if ($Output[-1] -match $Pattern) {
                $Matches.Remove(0)
                [PSCustomObject] $Matches | Select-Object -Property @(
                    @{ Name = 'Folder'; Expression = { $Job.Path } }
                    'FileCount'
                    'CroppedFaces'
                    'RejectedFaces'
                )
            }
        }
        
        [Console]::Beep(440,333)
        [Console]::Beep(494,333)
        [Console]::Beep(698,333)
    }
}