An Example of parsing command output text into Write-Progress from a Foreach -Parallel Pipeline

Show-MagickProgress.ps1

$commandOutput = @'
  save image[D:\2D\Test\Just Flow Dark 03.png]: 50 of 4500, 20% complete
  save image[D:\2D\Test\Just Flow Dark 03.png]: 100 of 4500, 40% complete
  save image[D:\2D\Test\Just Flow Dark 03.png]: 150 of 4500, 60% complete
  save image[D:\2D\Test\Just Flow Dark 05.png]: 50 of 4500, 20% complete
  save image[D:\2D\Test\Just Flow Dark 03.png]: 200 of 4500, 80% complete
  save image[D:\2D\Test\Just Flow Dark 03.png]: 250 of 4500, 90% complete
  save image[D:\2D\Test\Just Flow Dark 05.png]: 100 of 4500, 40% complete
  save image[D:\2D\Test\Just Flow Dark 05.png]: 150 of 4500, 60% complete
  save image[D:\2D\Test\Just Flow Dark 05.png]: 200 of 4500, 80% complete
  save image[D:\2D\Test\Just Flow Dark 04.png]: 50 of 4500, 20% complete
  save image[D:\2D\Test\Just Flow Dark 04.png]: 100 of 4500, 40% complete
  save image[D:\2D\Test\Just Flow Dark 04.png]: 150 of 4500, 60% complete
  save image[D:\2D\Test\Just Flow Dark 04.png]: 200 of 4500, 80% complete
  save image[D:\2D\Test\Just Flow Dark 04.png]: 250 of 4500, 90% complete
  save image[D:\2D\Test\Just Flow Dark 04.png]: 300 of 4500, 100% complete
  save image[D:\2D\Test\Just Flow Dark 03.png]: 300 of 4500, 100% complete
  save image[D:\2D\Test\Just Flow Dark 05.png]: 250 of 4500, 90% complete
  save image[D:\2D\Test\Just Flow Dark 05.png]: 300 of 4500, 100% complete
'@ -split '\n'



function Show-MagickProgres {
  [CmdletBinding()]
  param(
    [Parameter(ValueFromPipeline)]$MagickOutput
  )
  begin {
    #We want one progress per file name
    $PathToId = @{}
    #High number just so we don't conflict with any other progress
    [int]$activityId = 1000000

    #Top level progress indicator
    $parentId = Get-Random -min 9000 -max 10000
    Write-Progress -Id $parentId -Activity 'Batch ImageMagick Processing'
  }
  process {
    #Capture groups are used so we can pull straight from $matches
    $MagickOutputRegex = 'save image\[(?<path>.*)\]: (?<current>\d+) of (?<total>\d+), (?<percentage>\d+)% complete'
    if ($MagickOutput -notmatch $MagickOutputRegex) {
      Write-Error "Invalid output: $MagickOutput"
      return
    }

    #Fetch the ID for the file or create a new one
    $pathId = if ($PathToId.ContainsKey($matches.path)) {
      $PathToId[$matches.path]
    } else {
      $activityId++
      $PathToId[$matches.path] = $activityId
      $activityId
    }

    $ProgressParams = @{
      Id = $pathId
      ParentId = $parentId
      Activity = "Saving Image $($matches.path)"
      PercentComplete = $matches.percentage
      Status = "$($matches.current) of $($matches.total)"
    }
    Write-Progress @ProgressParams
  }
  end {
    Write-Progress -Id $ParentId -Activity 'Complete' -Completed
  }
}


$commandOutput | Foreach {sleep 0.5;$_} | Show-MagickProgres

Demo.mp4