Why does this Powershell Script create converted images OUTSIDE the Rootfolder?

Question

The following Powershell script is supposed to process all designated images INSIDE the specified Rootfolder. Some of the renamed output images are generated OUTSIDE the Rootfolder. Any Powershell gurus have any idea why? How can I output files only in the Rootfolder and not OUTSIDE the Rootfolder?

# This script requires ImageMagick
# Configuration
# Enter the full path of the folder that contains the images
$Rootfolder = "C:\temp\rktest"


$Recursive=$true
# Change these if necessary
$fileExtensions = "*.png"
$fileNameSuffix = "_resized" # the text to be appended to the output filename to indicate that it has been modified

$files = $null;
$fileCount = 0

# Check if the root folder is a valid folder. If not, try again.
if ((Test-Path $RootFolder -PathType 'Container') -eq $false) {
    Write-Host "'$RootFolder' doesn't seem to be a valid folder. Please try again" -ForegroundColor Red
    break
}

# Get all image files in the folder
if ($Recursive) {
    $files = gci $RootFolder -Filter $fileExtensions -File -Recurse
} 

# If there are no image files found, write out a message and quit
if ($files.Count -lt 1) {
    Write-Host "No image files with extension '$fileExtensions' were found in the folder '$RootFolder'" -ForegroundColor Red
    break
}

# Loop through each of the files and process it
foreach ($image in $files) {
    $newFilename = $image.DirectoryName + " " + $image.BaseName + $fileNameSuffix + $image.Extension
    $imageFullname = $image.FullName

    write-host "Processing image: $imageFullname" -ForegroundColor Green
#This line contains the ImageMagick commands
    & convert.exe $image.FullName -resize 50% $newFilename

    $fileCount++
}

Write-Host "$fileCount images processed" -ForegroundColor Yellow

Answer 1

Remove the space between directory and filename, put a backslash

$newFilename = $image.DirectoryName + "\" + $image.BaseName + $fileNameSuffix + $image.Extension

Answer 2

If I understand right the resized images should be placed in $RootFolder but retain the subfolder names as part of the filename, space separated.

The following script results in this sample tree:

> tree /F
C:.
└───temp
    └───rktest
        │   Image.png
        │   Image_resized.png
        │   SubDirL1 Image_resized.png
        │   SubDirL1 SubDirL2 Image_resized.png
        │
        └───SubDirL1
            │   Image.png
            │
            └───SubDirL2
                    Image.png

It creates a calculated property RelPAth with a select, adding it to the $file collection.
This is done by first removing the RootFolder from FullName and replacing any remaining path separators \ with spaces.

When building the new file name the extension is replaced with suffix+extension.

## Q:\Test\2018\06\02\SU_1327985.ps1
# This script requires ImageMagick
# Configuration
# Enter the full path of the folder that contains the images
$Rootfolder = "C:\temp\rktest"

$Recursive=$true
# Change these if necessary
$fileExtensions = "*.png"
$fileNameSuffix = "_resized" # the text to be appended to the output filename to indicate that it has been modified

$files = $null;
$fileCount = 0

# Check if the root folder is a valid folder. If not, try again.
if ((Test-Path $RootFolder -PathType 'Container') -eq $false) {
    Write-Host "'$RootFolder' doesn't seem to be a valid folder. Please try again" -ForegroundColor Red
    break
}

# Get all image files in the folder
if ($Recursive) {
    $files = gci $RootFolder -Filter $fileExtensions -File -Recurse |
      select *,@{n='RelPath';e={ ($_.FullName.Replace($RootFolder+"\",'')).Replace('\',' ') }}
} 

# If there are no image files found, write out a message and quit
if ($files.Count -lt 1) {
    Write-Host "No image files with extension '$fileExtensions' were found in the folder '$RootFolder'" -ForegroundColor Red
    break
}

# Loop through each of the files and process it
foreach ($image in $files) {
    $newFilename = Join-Path $RootFolder ($image.RelPath.Replace($image.Extension,($fileNameSuffix+$image.Extension)))
    write-host "Processing image: $($image.Fullname)" -ForegroundColor Green
    #This line contains the ImageMagick commands
    & magick convert $image.FullName -resize 50% $newFilename

    $fileCount++
}

Write-Host "$fileCount images processed" -ForegroundColor Yellow

Replaced convert.exe with magick convert due to my ImageMagick version.