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

README.md

@@ -230,6 +230,7 @@ Mega Collection of PowerShell Scripts
 | Script                                                 | Description                                                                                              |
 | ------------------------------------------------------ | -------------------------------------------------------------------------------------------------------- |
 | [convert-csv2txt.ps1](scripts/convert-csv2txt.ps1)     | Converts a .CSV file to a text file. [Read more »](docs/convert-csv2txt.md)                              |
+| [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) |
 | [convert-mysql2csv.ps1](scripts/convert-mysql2csv.ps1) | Converts a MySQL database table to a .CSV file. [More »](docs/convert-mysql2csv.md)                 |
 | [convert-ps2bat.ps1](scripts/convert-ps2bat.ps1)       | Converts a PowerShell script to a Batch script. [More »](docs/convert-ps2bat.md)                    |
 | [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

@@ -0,0 +1,39 @@
+# convert-images.ps1
+
+This PowerShell script converts images in a directory or a single image file to WebP format in parallel.
+
+## Parameters
+
+| Parameter | Description |
+| --- | --- |
+| `-InputPath` | The path to the input directory containing images or a single image file. |
+| `-OutputDir` | The path to the directory where the converted WebP files will be saved. It will be created if it doesn't exist. |
+| `-Quality` | The quality setting for the WebP conversion (0-100). Lower values mean smaller files but potentially lower quality. Defaults to 50. |
+| `-Lossless` | Specifies whether to use lossless WebP compression ($true) or lossy compression ($false). Defaults to $true. |
+| `-MaxParallel` | The maximum number of image conversions to run concurrently. Defaults to 10. |
+
+## Description
+
+The script takes advantage of PowerShell's parallel processing capabilities to efficiently convert multiple image files. It supports various input formats including:
+- jpg/jpeg
+- png
+- gif
+- bmp
+- tiff
+
+The converted files are saved in WebP format, which often provides superior compression while maintaining quality.
+
+## Examples
+
+```powershell
+# Convert all images in a directory
+./convert-images.ps1 -InputPath .\covers -OutputDir .\covers-webp -Quality 50 -Lossless $true -MaxParallel 10
+
+# Convert a single image
+./convert-images.ps1 -InputPath .\my_image.png -OutputDir .\output -Quality 80 -Lossless $false
+```
+
+## Requirements
+
+- PowerShell 7.0 or higher (required for ForEach-Object -Parallel)
+- ImageMagick must be installed and accessible via the 'magick' command in your PATH

scripts/convert-images2webp.ps1

@@ -0,0 +1,194 @@
+#Requires -Version 7.0
+
+<#
+.SYNOPSIS
+Converts images in a directory or a single image file to WebP format in parallel.
+
+.DESCRIPTION
+This script takes an input directory containing images (jpg, jpeg, png, gif, bmp, tiff) or a single image file,
+and converts them to the WebP format using ImageMagick's 'magick' command.
+The conversion process runs in parallel to speed up processing large numbers of files.
+The level of parallelism can be controlled.
+
+.PARAMETER InputPath
+The path to the input directory containing images or a single image file.
+
+.PARAMETER OutputDir
+The path to the directory where the converted WebP files will be saved. It will be created if it doesn't exist.
+
+.PARAMETER Quality
+The quality setting for the WebP conversion (0-100). Lower values mean smaller files but potentially lower quality. Defaults to 50.
+
+.PARAMETER Lossless
+Specifies whether to use lossless WebP compression ($true) or lossy compression ($false). Defaults to $true.
+
+.PARAMETER MaxParallel
+The maximum number of image conversions to run concurrently. Defaults to 10.
+
+.EXAMPLE
+.\convert_parallel.ps1 -InputPath .\covers -OutputDir .\covers-webp -Quality 50 -Lossless $true -MaxParallel 10
+Converts all supported images in the '.\covers' directory to WebP in '.\covers-webp' using quality 50, lossless compression, running up to 10 conversions simultaneously.
+
+.EXAMPLE
+.\convert_parallel.ps1 -InputPath .\my_image.png -OutputDir .\output -Quality 80 -Lossless $false
+Converts the single file '.\my_image.png' to WebP in '.\output' using quality 80 and lossy compression. Parallelism doesn't apply to single files.
+
+.NOTES
+Requires PowerShell 7.0 or higher for ForEach-Object -Parallel.
+Requires ImageMagick to be installed and accessible via the 'magick' command in your PATH.
+Progress reporting for parallel operations is limited; output messages might appear interleaved.
+#>
+param (
+    [Parameter(Mandatory=$true)]
+    [string]$InputPath,
+
+    [Parameter(Mandatory=$true)]
+    [string]$OutputDir,
+
+    [ValidateRange(0,100)]
+    [int]$Quality = 50,
+
+    [bool]$Lossless = $true,
+
+    [ValidateRange(1, [int]::MaxValue)] # Ensure at least 1 parallel task
+    [int]$MaxParallel = 10
+)
+
+# --- Input Validation and Setup ---
+
+# Check if input exists
+if (-not (Test-Path $InputPath)) {
+    Write-Error "Input path does not exist: $InputPath"
+    exit 1
+}
+
+# Create output directory if it doesn't exist
+if (-not (Test-Path $OutputDir -PathType Container)) {
+    Write-Host "Creating output directory: $OutputDir"
+    try {
+        New-Item -ItemType Directory -Path $OutputDir -ErrorAction Stop | Out-Null
+    } catch {
+        Write-Error "Failed to create output directory '$OutputDir': $_"
+        exit 1
+    }
+}
+
+# Check if ImageMagick is installed and accessible
+if (-not (Get-Command magick -ErrorAction SilentlyContinue)) {
+    Write-Error "ImageMagick is not installed or not in your PATH. Please install it from https://imagemagick.org/."
+    exit 1
+}
+
+# Check if input is a file or directory
+$InputItem = Get-Item $InputPath
+$isFileInput = $InputItem -is [System.IO.FileInfo]
+
+# Convert lossless parameter to string for command
+$losslessValue = $Lossless.ToString().ToLower()
+
+Write-Host "Starting conversion..."
+Write-Host "Input: $InputPath"
+Write-Host "Output: $OutputDir"
+Write-Host "Quality: $Quality"
+Write-Host "Lossless: $Lossless"
+if (!$isFileInput) {
+    Write-Host "Max Parallelism: $MaxParallel"
+}
+Write-Host "-------------------------------------"
+
+# --- Conversion Functions ---
+
+# Function to convert a single file (used for non-parallel case)
+function Convert-SingleFile {
+    param (
+        [string]$FilePath,
+        [string]$OutDir,
+        [int]$ConvQuality,
+        [string]$ConvLosslessValue
+    )
+
+    $fileName = [System.IO.Path]::GetFileName($FilePath)
+    $fileNameWithoutExt = [System.IO.Path]::GetFileNameWithoutExtension($FilePath)
+    $outputFilePath = Join-Path $OutDir "$fileNameWithoutExt.webp"
+
+    Write-Host "Converting '$fileName' to WebP..."
+    try {
+        # Use Start-Process to capture stderr better if needed, or stick with '&' for simplicity
+        & magick $FilePath -quality $ConvQuality -define webp:lossless=$ConvLosslessValue $outputFilePath
+        Write-Host "Successfully converted '$fileName' to '$outputFilePath'" -ForegroundColor Green
+    }
+    catch {
+        Write-Error "Failed to convert '$fileName': $_"
+        # Consider adding specific error details from stderr if using Start-Process
+    }
+}
+
+# --- Main Conversion Logic ---
+
+$startTime = Get-Date
+
+if ($isFileInput) {
+    # Process single file directly
+    Convert-SingleFile -FilePath $InputPath -OutDir $OutputDir -ConvQuality $Quality -ConvLosslessValue $losslessValue
+    $totalFiles = 1
+}
+else {
+    # Process all image files in directory using parallel processing
+    Write-Host "Gathering image files from '$InputPath'..."
+    $imageFiles = Get-ChildItem -Path $InputPath -File | Where-Object {
+        $_.Extension -match '\.(jpg|jpeg|png|gif|bmp|tiff)$'
+    }
+
+    $totalFiles = $imageFiles.Count
+    $processedCount = 0 # Simple counter, not perfectly synced for progress bar
+
+    if ($totalFiles -eq 0) {
+        Write-Warning "No supported image files found in '$InputPath'."
+        exit 0
+    }
+
+    Write-Host "Found $totalFiles image files. Starting parallel conversion (MaxParallel = $MaxParallel)..."
+
+    $imageFiles | ForEach-Object -Parallel {
+        # Variables from the outer scope need $using:
+        $currentFile = $_
+        $fName = $currentFile.Name
+        $fNameWithoutExt = $currentFile.BaseName
+        $outputFPath = Join-Path $using:OutputDir "$fNameWithoutExt.webp"
+
+        Write-Host "($PID) Starting conversion: $fName" # ($PID) shows the process ID handling this item
+
+        try {
+            # Execute ImageMagick command
+            & magick $currentFile.FullName -quality $using:Quality -define webp:lossless=$using:losslessValue $outputFPath
+
+            # Basic success message (output might be interleaved)
+            Write-Host "($PID) Finished conversion: $fName -> $outputFPath" -ForegroundColor Cyan
+        }
+        catch {
+            # Basic error message (output might be interleaved)
+            Write-Error "($PID) Failed to convert '$fName': $_"
+        }
+
+        # Incrementing a counter for precise progress in parallel is complex.
+        # This provides a basic idea but isn't a reliable progress bar.
+        # [System.Threading.Interlocked]::Increment([ref]$using:processedCount) | Out-Null
+        # $prog = [math]::Round(($using:processedCount / $using:totalFiles) * 100)
+        # Write-Progress -Activity "Converting images to WebP (Parallel)" -Status "Processed approx. $using:processedCount of $using:totalFiles" -PercentComplete $prog -Id 1
+
+    } -ThrottleLimit $MaxParallel # Control the number of parallel runs
+
+    # Write-Progress -Activity "Converting images to WebP (Parallel)" -Completed -Id 1
+    Write-Host "-------------------------------------"
+    Write-Host "Parallel conversion process finished."
+}
+
+$endTime = Get-Date
+$duration = $endTime - $startTime
+
+Write-Host "====================================="
+Write-Host "Conversion Summary"
+Write-Host "Total files processed: $totalFiles"
+Write-Host "Duration: $($duration.ToString())"
+Write-Host "Output directory: $OutputDir"
+Write-Host "=====================================" -ForegroundColor Green