Here’s how I do most of my batch resizings and recompressions :)
Those questions come quite often in the comments of my shares, “how can I resize all the images in that hentai manga”, or “the images are ridiculously huge, how do you recompress them?“.
Let’s address that, I’m explaining how I do it
Important: I don’t only do it that way. Actual retouchings are ran with photoshop (here’s how), particular image sets will sometimes require different methods, and on the rare blissful occasion nothing is necessary as the scanlators produced perfect images already. Still, the method I’m giving here should work most of the time.
And I’m certain better methods exist, okay, it’s not a contest
Rather than a wall of text, I’m explaining it in ONE image, I can’t do better
In that image, you’ll see my personal settings and every step I take, with occasional additional explanations.
I use the Xnview Classic program: it can work as both an image viewer, and a very handy mass-transformation tool.
With Xnview, I run both:
– the recompression operations (the width and height don’t change, but we recompress the images so that they take less kilobytes/megabytes on the disk)
– the resizing/shrinking operations (we reduce the image’s height, making it easier to read on a monitor and strongly reducing its kilobytes/megabites size)
Here’s my Xnview Recompression / Resizing Guide.
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(January 2021: this post was updated.)
In the past, to recompress the images, I would use another program, ACDsee. But, around 2018 I think, I eventually gave up on it: there was always a risk to still damage the images unless extra care was taken, I would have to come back to several different kinds of images to make sure I didn’t let damaging processing slip unnoticed… That wasn’t worth it.
With Xnview, the results of image recompressing will yield slightly larger sizes in total in megabytes, but there will be confidence no risk is taken. It’s safer.
Also, I slightly changed the default jpeg compression settings in Xnview, saving hundreds of files to disk will take a few more seconds if you’ve got a dying potato PC, but in exchange there’s stronger confidence the images will look as good as before their recompression.
A few useless options were also ticked off.
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Some personal bonus feedback, if you want to toy around and change the default jpeg compression settings in Xnview, I recommend you choose, for your before/after comparisons, an image with reddish surfaces, fading into other colours on the edges, and in deep reds in the center.
Again, it’s just personal experience (AKA: maybe it’s just me, it’s a P sample size of 1), but I noticed it’s those kinds of images that show the more easily when the compression has been too strong and there’s been damage.
… Look, I’m all for saving space by recompressing uselessly big images, but NOT at the cost of damaging image quality.
Would you really want to keep damaged hentai pics on your disk, just to save 30 megabytes, while at the same time you download gigabytes of porn torrents elsewhere on your disk? It’s not worth it, please preserve image quality ^^
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And if I want to rename files?
In Xnview, do Control-A to select all the images, and then F2. Remember the # symbol will be the incremental numbers, start with ## if there are less than 100 pictures (get the idea?), the rest should come easily.
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While I’m at it, I’ll have to update this post with fresher information, but, hey, I once wrote a post about the best friends of the hentai fan…
Pssst !
After 10 000 pictures seen with ACD See Classic, you’ll need a serial, for instance Mester as name and 475341886221327 as serial

Besides, it may prove useful if you start using ACD See Classic on a regular basis, make :
Tools > Options > Viewer > Full Screen > Save Default, and that’s all now the best options to view images
Protip: Decheck "save EXIF/IPTC data". You'll save even more kb.
Hm ? I never noted that, I'll try next time, thanks !
It really only matters with tanks. You might save an MB or so.
How about how you do batch renaming of all the files? For those of us who are tired of the 'sigh' shit.
I dunno what Oliver uses, but I use "Batch Rename Utility".
I use Better File Rename
Oookay, if we're with renaming, I updated my post to mention ACDSee and Xnview's renaming features.
If you really need super-duper-power renaming, I (rarely) use Lupas Rename (or renamer, or renaming, something like that).
To resize groups of images, I use Berberus Mass Image Resizer or Redimensionneur
To do a batch resize, I use Fotosizer. It’s free and it’s extremely easy to use. I will say, however, that my (currently out-of-date) virus protection stated the website for the program somehow compromised my computer’s security, so take that as a warning if you decide to go with this program.
I’ve been known to use Fotosizer, though only with copies on odd devices, I’ve never modified my archived original files. It’s a good program to work with.
I've long used the free IrfanView for viewing and batch tasks. In particular I use it to convert BMPs to PNGs to save space. For renaming I use Advanced Renamer which is powerful and free. Just my two cents
Xnview also has the neat feature of being able to open images in tabs. You can switch between tabs with your mouse wheel while your mouse is hovering over the tabs. (Sadly you cant set it up to switch between tabs anywhere on the screen.) Still good for comparing (similar) images.
For finding duplicate files (images) Ive tested a bunch of programmes a while back and settled on Alldup. You can launch it by right clicking on the desired folder. It has a file (image) preview. You can select all duplicates with the same path. It asks you what to do when all duplicats in 1 group have been selected, so you wont accidentally delete all the duplicates.
Anyone know of a good image viewer that allows you to quickly switch between "fit to window" and "100% zoom"?
That switching would be the / and * keyboard strokes
For duplicates, I use Visipics. That prog's doing WONDERS, finding duplicates, you can customize the similarity level recognition feature, and you can set the program up so that it will, ultimately, only keep the largest resolution image without bothering you with a billion confirmations.
Good to know.
Ill check out Visipics when I get the time.
one program to rule them all
HoneyView 3 or 꿀뷰 3.
sadly he doesn't seem to update the english version much nowadays, but either version I found is the best image/archive/zip general use image viewer out there.
very fast as well.
The possibility to browse compressed folders is nice. It does however have some big let downs.
For the love of me I cant find where you can set the default zoom level. Fit to window seems to be the default .
The huge zoom level bubble that fades in and out is also a bit annoying.
I am using XnConvert, it is basically XnView without the browser part.
Just set up your conversion preferences and convert with just a few clicks (right click on folder, left click to run XnConvert, left click convert button)
renamer I use http://www.den4b.com (powerful, free, easy to use)
viewing images within a zip file, CDisplay (I use it to read manga)
Un peu en retard, mais merci pour la découverte des logiciels et les tutos, vraiment utile !
What about Faststone http://www.faststone.org/ ? It has a powerfull batch resize/convert. Also, it’s free…
Total Commander also has a fairly good multi rename tool which does the job for me when needed