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Add convert-images2webp.ps1 script and documentation for image conversion to WebP format
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‎README.md

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@@ -230,6 +230,7 @@ Mega Collection of PowerShell Scripts
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| Script | Description |
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| ------------------------------------------------------ | -------------------------------------------------------------------------------------------------------- |
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| [convert-csv2txt.ps1](scripts/convert-csv2txt.ps1) | Converts a .CSV file to a text file. [Read more »](docs/convert-csv2txt.md) |
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| [convert-images2webp.ps1](scripts/convert-images2webp.ps1) | Converts images in a directory or a single image file to WebP format in parallel. [More »](docs/convert-images2webp.md) |
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| [convert-mysql2csv.ps1](scripts/convert-mysql2csv.ps1) | Converts a MySQL database table to a .CSV file. [More »](docs/convert-mysql2csv.md) |
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| [convert-ps2bat.ps1](scripts/convert-ps2bat.ps1) | Converts a PowerShell script to a Batch script. [More »](docs/convert-ps2bat.md) |
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| [convert-ps2md.ps1](scripts/convert-ps2md.ps1) | Converts the comment-based help of a PowerShell script to Markdown. [More »](docs/convert-ps2md.md) |

‎docs/convert-images2webp.md

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# convert-images.ps1
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This PowerShell script converts images in a directory or a single image file to WebP format in parallel.
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## Parameters
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| Parameter | Description |
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| --- | --- |
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| `-InputPath` | The path to the input directory containing images or a single image file. |
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| `-OutputDir` | The path to the directory where the converted WebP files will be saved. It will be created if it doesn't exist. |
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| `-Quality` | The quality setting for the WebP conversion (0-100). Lower values mean smaller files but potentially lower quality. Defaults to 50. |
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| `-Lossless` | Specifies whether to use lossless WebP compression ($true) or lossy compression ($false). Defaults to $true. |
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| `-MaxParallel` | The maximum number of image conversions to run concurrently. Defaults to 10. |
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## Description
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The script takes advantage of PowerShell's parallel processing capabilities to efficiently convert multiple image files. It supports various input formats including:
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- jpg/jpeg
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- png
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- gif
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- bmp
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- tiff
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The converted files are saved in WebP format, which often provides superior compression while maintaining quality.
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## Examples
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```powershell
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# Convert all images in a directory
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./convert-images.ps1 -InputPath .\covers -OutputDir .\covers-webp -Quality 50 -Lossless $true -MaxParallel 10
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# Convert a single image
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./convert-images.ps1 -InputPath .\my_image.png -OutputDir .\output -Quality 80 -Lossless $false
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```
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## Requirements
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- PowerShell 7.0 or higher (required for ForEach-Object -Parallel)
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- ImageMagick must be installed and accessible via the 'magick' command in your PATH

‎scripts/convert-images2webp.ps1

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#Requires -Version 7.0
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<#
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.SYNOPSIS
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Converts images in a directory or a single image file to WebP format in parallel.
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.DESCRIPTION
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This script takes an input directory containing images (jpg, jpeg, png, gif, bmp, tiff) or a single image file,
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and converts them to the WebP format using ImageMagick's 'magick' command.
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The conversion process runs in parallel to speed up processing large numbers of files.
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The level of parallelism can be controlled.
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.PARAMETER InputPath
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The path to the input directory containing images or a single image file.
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.PARAMETER OutputDir
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The path to the directory where the converted WebP files will be saved. It will be created if it doesn't exist.
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.PARAMETER Quality
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The quality setting for the WebP conversion (0-100). Lower values mean smaller files but potentially lower quality. Defaults to 50.
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.PARAMETER Lossless
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Specifies whether to use lossless WebP compression ($true) or lossy compression ($false). Defaults to $true.
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.PARAMETER MaxParallel
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The maximum number of image conversions to run concurrently. Defaults to 10.
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.EXAMPLE
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.\convert_parallel.ps1 -InputPath .\covers -OutputDir .\covers-webp -Quality 50 -Lossless $true -MaxParallel 10
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Converts all supported images in the '.\covers' directory to WebP in '.\covers-webp' using quality 50, lossless compression, running up to 10 conversions simultaneously.
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.EXAMPLE
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.\convert_parallel.ps1 -InputPath .\my_image.png -OutputDir .\output -Quality 80 -Lossless $false
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Converts the single file '.\my_image.png' to WebP in '.\output' using quality 80 and lossy compression. Parallelism doesn't apply to single files.
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.NOTES
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Requires PowerShell 7.0 or higher for ForEach-Object -Parallel.
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Requires ImageMagick to be installed and accessible via the 'magick' command in your PATH.
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Progress reporting for parallel operations is limited; output messages might appear interleaved.
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#>
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param (
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[Parameter(Mandatory=$true)]
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[string]$InputPath,
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[Parameter(Mandatory=$true)]
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[string]$OutputDir,
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[ValidateRange(0,100)]
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[int]$Quality = 50,
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[bool]$Lossless = $true,
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[ValidateRange(1, [int]::MaxValue)] # Ensure at least 1 parallel task
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[int]$MaxParallel = 10
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)
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# --- Input Validation and Setup ---
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# Check if input exists
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if (-not (Test-Path $InputPath)) {
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Write-Error "Input path does not exist: $InputPath"
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exit 1
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}
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# Create output directory if it doesn't exist
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if (-not (Test-Path $OutputDir -PathType Container)) {
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Write-Host "Creating output directory: $OutputDir"
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try {
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New-Item -ItemType Directory -Path $OutputDir -ErrorAction Stop | Out-Null
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} catch {
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Write-Error "Failed to create output directory '$OutputDir': $_"
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exit 1
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}
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}
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# Check if ImageMagick is installed and accessible
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if (-not (Get-Command magick -ErrorAction SilentlyContinue)) {
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Write-Error "ImageMagick is not installed or not in your PATH. Please install it from https://imagemagick.org/."
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exit 1
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}
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# Check if input is a file or directory
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$InputItem = Get-Item $InputPath
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$isFileInput = $InputItem -is [System.IO.FileInfo]
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# Convert lossless parameter to string for command
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$losslessValue = $Lossless.ToString().ToLower()
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Write-Host "Starting conversion..."
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Write-Host "Input: $InputPath"
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Write-Host "Output: $OutputDir"
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Write-Host "Quality: $Quality"
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Write-Host "Lossless: $Lossless"
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if (!$isFileInput) {
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Write-Host "Max Parallelism: $MaxParallel"
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}
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Write-Host "-------------------------------------"
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# --- Conversion Functions ---
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# Function to convert a single file (used for non-parallel case)
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function Convert-SingleFile {
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param (
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[string]$FilePath,
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[string]$OutDir,
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[int]$ConvQuality,
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[string]$ConvLosslessValue
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)
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$fileName = [System.IO.Path]::GetFileName($FilePath)
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$fileNameWithoutExt = [System.IO.Path]::GetFileNameWithoutExtension($FilePath)
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$outputFilePath = Join-Path $OutDir "$fileNameWithoutExt.webp"
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Write-Host "Converting '$fileName' to WebP..."
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try {
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# Use Start-Process to capture stderr better if needed, or stick with '&' for simplicity
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& magick $FilePath -quality $ConvQuality -define webp:lossless=$ConvLosslessValue $outputFilePath
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Write-Host "Successfully converted '$fileName' to '$outputFilePath'" -ForegroundColor Green
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}
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catch {
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Write-Error "Failed to convert '$fileName': $_"
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# Consider adding specific error details from stderr if using Start-Process
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}
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}
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# --- Main Conversion Logic ---
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$startTime = Get-Date
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if ($isFileInput) {
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# Process single file directly
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Convert-SingleFile -FilePath $InputPath -OutDir $OutputDir -ConvQuality $Quality -ConvLosslessValue $losslessValue
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$totalFiles = 1
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}
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else {
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# Process all image files in directory using parallel processing
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Write-Host "Gathering image files from '$InputPath'..."
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$imageFiles = Get-ChildItem -Path $InputPath -File | Where-Object {
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$_.Extension -match '\.(jpg|jpeg|png|gif|bmp|tiff)$'
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}
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$totalFiles = $imageFiles.Count
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$processedCount = 0 # Simple counter, not perfectly synced for progress bar
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if ($totalFiles -eq 0) {
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Write-Warning "No supported image files found in '$InputPath'."
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exit 0
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}
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Write-Host "Found $totalFiles image files. Starting parallel conversion (MaxParallel = $MaxParallel)..."
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$imageFiles | ForEach-Object -Parallel {
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# Variables from the outer scope need $using:
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$currentFile = $_
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$fName = $currentFile.Name
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$fNameWithoutExt = $currentFile.BaseName
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$outputFPath = Join-Path $using:OutputDir "$fNameWithoutExt.webp"
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Write-Host "($PID) Starting conversion: $fName" # ($PID) shows the process ID handling this item
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try {
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# Execute ImageMagick command
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& magick $currentFile.FullName -quality $using:Quality -define webp:lossless=$using:losslessValue $outputFPath
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# Basic success message (output might be interleaved)
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Write-Host "($PID) Finished conversion: $fName -> $outputFPath" -ForegroundColor Cyan
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}
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catch {
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# Basic error message (output might be interleaved)
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Write-Error "($PID) Failed to convert '$fName': $_"
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}
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# Incrementing a counter for precise progress in parallel is complex.
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# This provides a basic idea but isn't a reliable progress bar.
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# [System.Threading.Interlocked]::Increment([ref]$using:processedCount) | Out-Null
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# $prog = [math]::Round(($using:processedCount / $using:totalFiles) * 100)
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# Write-Progress -Activity "Converting images to WebP (Parallel)" -Status "Processed approx. $using:processedCount of $using:totalFiles" -PercentComplete $prog -Id 1
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} -ThrottleLimit $MaxParallel # Control the number of parallel runs
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# Write-Progress -Activity "Converting images to WebP (Parallel)" -Completed -Id 1
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Write-Host "-------------------------------------"
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Write-Host "Parallel conversion process finished."
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}
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$endTime = Get-Date
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$duration = $endTime - $startTime
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Write-Host "====================================="
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Write-Host "Conversion Summary"
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Write-Host "Total files processed: $totalFiles"
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Write-Host "Duration: $($duration.ToString())"
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Write-Host "Output directory: $OutputDir"
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Write-Host "=====================================" -ForegroundColor Green

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