I have a lot of duplicate image files on my Windows computer, in different subfolders and with different file names.
What Python script or freeware program would you recommend for removing the duplicates?
(I've read this similar question, but the poster there is asking about visual duplicates with differing file sizes. Mine are exact duplicates with different file names.)
Don't Rely on MD5 sums.
MD5 sums are not a reliable way to check for duplicates, they are only a way to check for differences.
Use MD5s to find possible candidate duplicates, and then for each pair sharing an MD5
Seeing I'm getting downvoted by people doing naïve approaches to file duplicate Identity, If you're going to rely entirely on a hash algorithm, for goodness sake, use something tougher like SHA256 or SHA512, at least you'll reduce the probability to a reasonable degree by having more bits checked. MD5 is Exceedingly weak for collision conditions.
I also advise people read mailing lists here titled 'file check' : http://london.pm.org/pipermail/london.pm/Week-of-Mon-20080714/thread.html
If you say "MD5 can uniquely identify all files uniquely" then you have a logic error.
Given a range of values, of varying lengths from 40,000 bytes in length to 100,000,000,000 bytes in length, the total number of combinations available to that range greatly exceeds the possible number of values represented by MD5, weighing in at a mere 128 bits of length.
Represent 2^100,000,000,000 combinations with only 2^128 combinations? I don't think that likely.
The least naïve way, and the fastest way, to weed out duplicates is as follows.
Fdupes does this. And you should use software that uses the same criteria.
It's a one liner on unix like (including linux) OSes or Windows with Cygwin installed:
find . -type f -print0 | xargs -0 shasum | sort |
perl -ne '$sig=substr($_, 0, 40); $file=substr($_, 42); \
unlink $file if $sig eq $prev; $prev = $sig'
md5sum (which is about 50% faster) can be used if you know there is no deliberately created collisions (you'd have better chance to win 10 major lotteries than the chance to find one naturally occurring md5 collision.)
If you want to see all the dups you have instead of removing them just change the unlink $file part to print $file, "\n".
I've used fdupes (written in C) and freedups (Perl) on Unix systems, and they might work on Windows as well; there are also similar ones that are claimed to work on Windows: dupmerge, liten (written in Python), etc.
To remove duplicate images on Windows take a look at DupliFinder. It can compare pictures by a variety of criteria such as name, size, and actual image information.
For other tools to remove duplicate files take a look at this Lifehacker article.
One option can be Dupkiller.
DupKiller is one of the fastest and the most powerful tools for searching and removing duplicate or similar files on your computer. Complicated algorithms, built in its searching mechanism, perform high results — rapid file search. A lot of options allow to flexibly customizing the search.
A powershell way to scan for duplicate images ('.jpg','.png','.gif','.jpeg','.webp','.tiff','.psd','.raw','.bmp','.heif','indd','.svg' formats supported):
$sig=@'
public static void ShowConsoleWindow(int state)
{
var handle = GetConsoleWindow();
ShowWindow(handle,state);
}
[System.Runtime.InteropServices.DllImport("kernel32.dll")]
static extern IntPtr GetConsoleWindow();
[System.Runtime.InteropServices.DllImport("user32.dll")]
static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
'@
$hc=Add-Type -mem $sig -name Hide -Names HideConsole -Ref System.Runtime.InteropServices -Pas
$hc::ShowConsoleWindow(0)
[console]::title="Duplicate Image Scanner (c) Wasif Hasan | Sep 2020"
$eXt=@('.jpg','.png','.gif','.jpeg','.webp','.tiff','.psd','.raw','.bmp','.heif','indd','.svg')
@('system.windows.forms','system.drawing')|%{add-type -as $_}
$s=[windows.forms.form]::new();$s.size=[drawing.size]::new(400,850);$s.StartPosition="CenterScreen";$s.Text="Select drives to scan"
$drives=gdr -p "FileSystem"|select -eXp name
$top=20;$left=50;$drives|%{
$c=$_.split(" ")-join"_";$top += 20
iex "`$$($c) = New-Object System.Windows.Forms.CheckBox;`$$($c).Top = $($top);`$$($c).Left = $($left);`$$($c).Anchor='Left,Top';`$$($c).Parent='';`$$($c).Text='$($_)';`$$($c).Autosize=`$true;if('$_' -in `$drives){`$$c.Checked=`$true};`$s.Controls.Add(`$$c)"
}
$ok=New-Object System.Windows.Forms.Button;$ok.Text='OK';$ok.Top=770;$ok.Left=290
$ok.add_click({$s.Close()});$s.Controls.AddRange($ok)
$sa=New-Object System.Windows.Forms.Button;$sa.Text='Select All';$sa.Top=770;$sa.Left=200
$sa.add_click({$s.Controls|?{($_.Checked) -or !($_.Checked)}|%{try{$_.Checked=$True}catch{}}});$s.Controls.AddRange($sa)
$null=$s.ShowDialog()
$choices=$s.Controls|?{$_.Checked}|select -eXp Text
$i=0;$choices|%{$choices[$i]=$_+':\';$i++}
$f=[windows.forms.form]::new();$f.Size=[drawing.size]::new(600,100);$f.StartPosition="CenterScreen";$f.Text="Please wait"
$l=[windows.forms.label]::new();$l.Text="Please wait until the scan is complete........";$l.Font="Segoe UI,16";$l.AutoSize=$true;$f.Controls.AddRange($l)
$null=$f.ShowDialog()
$files=@();$hCols=@();$choices|%{
dir $_ -r|?{$_.eXtension-in$eXt}|%{
$h=get-filehash $_.fullname -a 'SHA256'|select -eXp hash
if($h-in$hCols){$files+=$_.fullName}else{$hCols+=$h}
}};$f.Close()
$del=$files|ogv -t "Duplicate images (Hold CTRL and select the ones to delete)" -p
$del|%{rm "$_" -fo}
[windows.forms.messagebox]::Show("Thanks for using!","Duplicate image scanner","OK","Information")
Instead of DupliFinder, try the forked project instead, DeadRinger. We've fixed a ton of bugs in the original project, added a bunch of new features, and dramatically improved performance.
