Problems with converting multiple PNGs to 32-Bit ICO using ImageMagick in PowerShell.

Convert-SVGtoICO Magick Errors.ps1

using namespace System.Collections.Generic
using namespace System.Collections.Concurrent
using namespace System.IO

function Convert-SVGToICOWorking {
    [CmdletBinding(DefaultParameterSetName = "Path")]
    param (
        [Parameter(
            Mandatory,
            Position = 0,
            ValueFromPipeline,
            ValueFromPipelineByPropertyName,
            ParameterSetName = "Path",
            HelpMessage="Path to one or more SVG files."
        )]
        [SupportsWildcards()]
        [ValidateNotNullOrEmpty()]
        [String[]] $Path,

        [Parameter(
            Mandatory,
            Position = 0,
            ValueFromPipelineByPropertyName,
            ParameterSetName = "LiteralPath",
            HelpMessage="Literal path to one or more SVG files."
        )]
        [ValidateScript({$_ -notmatch '[\?\*]'},
            ErrorMessage = "Wildcard characters *, ? are not acceptable with -LiteralPath")]
        [ValidateScript({[System.IO.Path]::IsPathRooted($_)},
            ErrorMessage = "Relative paths are not allowed in -LiteralPath.")]
        [Alias('PSPath')]
        [ValidateNotNullOrEmpty()]
        [String[]] $LiteralPath,

        [Parameter(HelpMessage = "If set, ICO files will be placed in a subfolder of the SVGs containing directory.")]
        [Switch] $OutputInSubfolder,

        [Parameter(HelpMessage = "The name of the subfolder to place ICO files if -OutputInSubfolder is set.")]
        [String] $SubfolderName = 'ICO Conversion',

        [Parameter(HelpMessage = "The number of simultaneous threads to use during conversion.")]
        [Int32] $MaxThreads = 20
    )

    begin {
        $rsvgCmd = Get-Command rsvg-convert.exe -EA 0
        if(-not$rsvgCmd){
            Write-Error "rsvg-convert.exe cannot be found in PATH. Aborting"
            return
        }
        $magickCmd = Get-Command magick.exe -EA 0
        if(-not$magickCmd){
            Write-Error "magick.exe (ImageMagick) cannot be found in PATH. Aborting"
            return
        }
        $svgList = [List[FileInfo]]@()
    }

    process {
        $resolvedPaths = if($PSBoundParameters['Path']) {
            $Path | Get-Item -Force
        } elseif($PSBoundParameters['LiteralPath']) {
            Get-Item -LiteralPath $LiteralPath -Force
        }
        $resolvedPaths | % {
            $fileName = $_.FullName
            if (Test-Path -LiteralPath $fileName -PathType Container) {
                $gciSplat = @{
                    LiteralPath = $fileName
                    Force       = $true
                    Recurse     = $true
                    ErrorAction = 'SilentlyContinue'
                    File        = -File
                    Filter      = '*.svg'
                }
                $childItems = Get-ChildItem @gciSplat
                if($childItems){
                    foreach ($item in $childItems) {
                        $null = $svgList.Add($item)
                    }
                }
            } elseif(Test-Path -LiteralPath $fileName -PathType Leaf) {
                if($_.Extension -eq '.svg'){
                    $null = $svgList.Add($_)
                }
            }
        }
    }
    end {

        $tempDirDict = [ConcurrentDictionary[String,String]]::new()

        if($PSBoundParameters['OutputInSubfolder']){
            $tempDirName = $SubfolderName
        } else {
            $tempDirName = ((New-Guid).Guid)
        }

        $svgList | ForEach-Object -Parallel {

            $curSvg          = $_.FullName
            $curSvgBaseName  = $_.BaseName
            $curSvgDir       = $_.Directory
            $tempDirName     = $Using:tempDirName
            $tempDirDict     = $using:tempDirDict
            $rsvgCmd         = $Using:rsvgCmd
            $magickCmd       = $Using:magickCmd

            $tempFolder = Join-Path -Path $curSvgDir -ChildPath $tempDirName
            if(-not($tempFolder | Test-Path -PathType Container)){
                New-Item -Path $tempFolder -ItemType Directory -Force | Out-Null
            }

            $icoSizes = @(16, 20, 24, 32, 48, 64, 96, 128, 256)
            foreach ($size in $icoSizes) {
                $rsvgParams = "-a", "-w", $size, "-h", $size, "-f", "png", $curSvg, "-o", "$tempFolder\$curSvgBaseName-$size.png"
                & $rsvgCmd $rsvgParams | Out-Null
            }

            $magickCmd = Get-Command magick.exe -CommandType Application
            $printArgs = Get-Command print_argv.exe -CommandType Application

            # COMMAND 1: Works but throws error: magick.exe: Cannot write image with defined
            # png:bit-depth or png:color-type. `' @ warning/png.c/MagickPNGWarningHandler/1526.

            & $printArgs $($icoSizes.ForEach{"$tempFolder\$curSvgBaseName-$_.png"}) "$tempFolder\$curSvgBaseName.ico"
            & $magickCmd $($icoSizes.ForEach{"$tempFolder\$curSvgBaseName-$_.png"}) "$tempFolder\$curSvgBaseName.ico"

            # COMMAND 2: Works but throws Inkscape errors: (org.inkscape.Inkscape:13820):
            # WARNING **: 06:50:22.942: Failed to find resource file 'svg2ico.py'. Looked in:
            # C:\Users\username\AppData\Roaming\inkscape\extensions\svg2ico.py

            # & $printArgs -background none $curSvg -define icon:auto-resize="16,20,24,32,48,64,96,128,256" -depth 32 "$tempFolder\$curSvgBaseName.ico"
            # & $magickCmd -background none $curSvg -define icon:auto-resize="16,20,24,32,48,64,96,128,256" -depth 32 "$tempFolder\$curSvgBaseName.ico"

            if (-not ($tempDirDict.Values -contains $tempFolder)) {
                $null = $tempDirDict.TryAdd($((New-Guid).Guid), $tempFolder) | Out-Null
            }

        } -ThrottleLimit $MaxThreads

        $tempDirDict.GetEnumerator() | % {

            $tempDir       = Get-Item -LiteralPath $($_.Value) -Force
            $tempDirFull   = $tempDir.FullName
            $tempDirParent = $tempDir.Parent

            Get-ChildItem $tempDirFull -Filter '*.png' -Recurse -Force | Remove-Item -Force
            if(-not($PSBoundParameters['OutputInSubfolder'])){
                $icoFiles = Get-ChildItem -LiteralPath $tempDirFull -Filter '*.ico' -Recurse -Force
                $icoFiles | % {
                    $curIcoFullname = $_.FullName
                    $icoDestPath = [System.IO.Path]::Combine($tempDirParent, $_.Name)
                    $icoDestPath = Get-UniqueNameIfDuplicate -LiteralPath $icoDestPath
                    Move-Item -LiteralPath $curIcoFullname -Destination $icoDestPath -Force | Out-Null
                }
                Remove-Item -LiteralPath $tempDirFull -Recurse -Force | Out-Null
            }
        }
    }
}

Convert-SVGToICOWorking -LiteralPath "C:\Icons\00 Apps\Chrome\00 Source\FM Chrome Light Black 03.svg" -OutputInSubfolder