Fixing file filter to read jpg only.

Author: KUTlime

GoogleImageSearch/GoogleImageSearch.psd1

@@ -8,7 +8,7 @@
         $ImagePath
     )
 
-    # Extract the image file name, without path.
+    # Extract the image file name, without Path.
     $fileName = Split-Path $imagePath -Leaf
     Write-Verbose -Message "The image name for search: $fileName"
 
@@ -92,7 +92,7 @@ function Search-WindowsLockScreenWallpapers
       Specifies a switch if wallpaper images should be dumped or not. A default value is False.
 
       .PARAMETER DumpPath
-      Specifies a path to a folder where the wallpapers should be dumped. The input can be a string or a valid instance of the System.IO.FileInfo class. A default value is 'C:\Temp'. The input directory is created if doesn't exist.
+      Specifies a Path to a folder where the wallpapers should be dumped. The input can be a string or a valid instance of the System.IO.FileInfo class. A default value is 'C:\Temp'. The input directory is created if doesn't exist.
 
       .EXAMPLE
       Search-WindowsLockScreenWallpapers
@@ -112,7 +112,7 @@ function Search-WindowsLockScreenWallpapers
 
       .NOTES
       - This cmdlet uses non-standard way how to query Google Image Search. Do not use it for automatization.
-      - A dump path is created if it doesn't exist.
+      - A dump Path is created if it doesn't exist.
 
       .LINK
       https://github.com/KUTlime/PowerShell-GoogleImageSearch-Module
@@ -155,7 +155,7 @@ function Search-WindowsLockScreenWallpapers
     # Select Images
     ####################################################
     $Images = Get-ChildItem -Path $env:LOCALAPPDATA\Packages\Microsoft.Windows.ContentDeliveryManager_cw5n1h2txyewy\LocalState\Assets -ErrorAction Continue |
-    Where-Object { $_.Length / 1KB -gt 200 }
+    Where-Object { (Get-KnownFileHeader -Path $_.FullName) -eq 'jpg'}
     $Images = $Images | Get-Image | Where-Object { $_.Width -gt $_.Height } | Sort-Object { $_.CreationTimeUtc } -Descending | Select-Object -First $NumberOfImages
     ####################################################
 
@@ -182,11 +182,11 @@ function Search-Image
       The Search-Image cmdlet reads the image and use this image to query Google Image Search. This cmdlet can be piped to the Get-ChildItem cmdlet for a batch processing.
 
       .PARAMETER ImagePath
-      Specifies a path to a image file. The input can be a string or a valid instance of the System.IO.FileInfo class.
+      Specifies a Path to a image file. The input can be a string or a valid instance of the System.IO.FileInfo class.
 
       .EXAMPLE
       Search-Image -ImagePath C:\Pictures\SomeImageToSearch.jpg
-      Reads the image SomeImageToSearch.jpg in C:\Pictures path and use this image to query Google Image Search.
+      Reads the image SomeImageToSearch.jpg in C:\Pictures Path and use this image to query Google Image Search.
 
       .EXAMPLE
       Get-ChildItem -Path 'C:\Pictures' -Filter '*.jpg' | Search-Image
@@ -214,4 +214,134 @@ function Search-Image
         $ImagePath
     )
     Start-Process -FilePath (Get-GoogleImageSearchUrl -ImagePath $ImagePath.FullName)
+}
+
+function Get-KnownFileHeader
+{
+    [OutputType([String])]
+    Param (
+        [Parameter(Mandatory = $true,
+            ValueFromPipeline = $true)]
+        [ValidateNotNullOrEmpty()]
+        [ValidateScript( { Test-Path $_ })]
+        [System.IO.FileInfo]
+        $Path
+    )
+    Begin
+    {
+        # Hexadecimal signatures for expected files
+        $known = @'
+"Extension","Header"
+"3gp","66 74 79 70 33 67"
+"7z","37 7A BC AF 27 1C"
+"8sv","38 53 56 58"
+"8svx","46 4F 52 4D nn nn nn nn"
+"acbm","46 4F 52 4D nn nn nn nn"
+"aif","41 49 46 46"
+"aiff","46 4F 52 4D nn nn nn nn"
+"anbm","46 4F 52 4D nn nn nn nn"
+"anim","46 4F 52 4D nn nn nn nn "
+"asf","30 26 B2 75 8E 66 CF 11"
+"avi","52 49 46 46 nn nn nn nn "
+"bac","42 41 43 4B 4D 49 4B 45"
+"bpg","42 50 47 FB"
+"cab","4D 53 43 46"
+"cin","80 2A 5F D7"
+"class","CA FE BA BE"
+"cmus","46 4F 52 4D nn nn nn nn"
+"cr2","49 49 2A 00 10 00 00 00"
+"crx","43 72 32 34"
+"cwk","05 07 00 00 42 4F 42 4F"
+"cwk","06 07 E1 00 42 4F 42 4F"
+"dat","50 4D 4F 43 43 4D 4F 43"
+"DBA","BE BA FE CA"
+"DBA","00 01 42 44"
+"dex","64 65 78 0A 30 33 35 00"
+"djvu","41 54 26 54 46 4F 52 4D nn nn nn nn 44 4A 56"
+"dmg","78 01 73 0D 62 62 60"
+"doc","D0 CF 11 E0 A1 B1 1A E1"
+"dpx","53 44 50 58"
+"exr","76 2F 31 01"
+"fax","46 41 58 58"
+"faxx","46 4F 52 4D nn nn nn nn"
+"fh8","41 47 44 33"
+"fits","53 49 4D 50 4C 45 20 20"
+"flac","66 4C 61 43"
+"flif","46 4C 49 46"
+"ftxt","46 4F 52 4D nn nn nn nn"
+"gif","47 49 46 38 37 61"
+"ico","00 00 01 00"
+"idx","49 4E 44 58"
+"iff","41 43 42 4D"
+"iff","41 4E 42 4D"
+"iff","41 4E 49 4D"
+"iff","46 4F 52 4D nn nn nn nn"
+"ilbm","46 4F 52 4D nn nn nn nn"
+"iso","43 44 30 30 31"
+"jpg","FF D8 FF DB"
+"jpg","FF D8 FF E0"
+"lbm","49 4C 42 4D"
+"lz","4C 5A 49 50"
+"lz4","04 22 4D 18"
+"mid","4D 54 68 64"
+"mkv","1A 45 DF A3"
+"MLV","4D 4C 56 49"
+"mus","43 4D 55 53"
+"nes","4E 45 53 1A"
+"ods","50 4B 05 06"
+"ogg","4F 67 67 53"
+"PDB","00 00 00 00 00 00 00 00"
+"pdf","25 50 44 46"
+"png","89 50 4E 47 0D 0A 1A 0A"
+"ps","25 21 50 53"
+"psd","38 42 50 53"
+"rar","52 61 72 21 1A 07 00"
+"rar","52 61 72 21 1A 07 01 00"
+"smu","53 4D 55 53"
+"smus","46 4F 52 4D nn nn nn nn"
+"stg","4D 49 4C 20"
+"tar","75 73 74 61 72 00 30 30"
+"TDA","00 01 44 54"
+"tif","49 49 2A 00"
+"toast","45 52 02 00 00 00"
+"tox","74 6F 78 33"
+"txt","46 54 58 54"
+"vsdx","50 4B 07 08"
+"wav","52 49 46 46 nn nn nn nn"
+"wma","A6 D9 00 AA 00 62 CE 6C"
+"xar","78 61 72 21"
+"yuv","59 55 56 4E"
+"yuvn","46 4F 52 4D nn nn nn nn"
+"zip","50 4B 03 04"
+"epub","50 4B 03 04 0A 00 02 00"
+'@ | ConvertFrom-Csv | Sort-Object { $_.header.Length } -Descending
+
+    $known | ForEach-Object { $_.header = $_.header -replace '\s' }
+    }
+    Process
+    {
+        $HeaderAsHexString = New-Object System.Text.StringBuilder
+        if ($PSVersionTable.PSVersion.Major -gt 5)
+        {
+            $bytes = [Byte[]](Get-Content -Path $Path.FullName -TotalCount 4 -AsByteStream -ErrorAction:Continue)
+        }
+        else
+        {
+            $bytes = [Byte[]](Get-Content -Path $Path.FullName -TotalCount 4 -Encoding:Byte -ErrorAction:Continue)
+        }
+        $bytes |
+        ForEach-Object `
+        {
+            if (("{0:X}" -f $_).Length -eq 1)
+            {
+                $HeaderAsHexString.Append('0{0:X}' -f $_) | Write-Verbose
+            }
+            else
+            {
+                $HeaderAsHexString.Append('{0:X}' -f $_) | Write-Verbose
+            }
+        }
+
+        $known | Where-Object { $_.Header.StartsWith($HeaderAsHexString.ToString()) } | Select-Object -First 1 | ForEach-Object { $_.Extension }
+    }
 }