As you know, I frequently share retouched versions on Hentairules. And… in order to be able to do it yourselves…  would you be interested in knowing how I do it ?

There are certainly hundreds of ways to retouch pictures and fix mangas, however, regarding scanlated hentai mangas, I am ALMOST ALWAYS doing the two same things :
– adjusting levels
– smoothing the surfaces against surface defects (those areas with just one color or a progressive shade of a color nuance, full of visual bugs because of printing or scanning)

If you have a manga with this kind of defects, to fix it, the way I do it is very simple. Here’s the how-to ;)

.  > Make a copy of one of the files to retouch, an image that “represents” how the other pics will be. That will be your test pic.

.  > Open photoshop (CS5 and Windows 7 at home, Mac users, may god have mercy on your soul if you tell me you too would need photoshop guidance.)

. > Open the copied file to retouch in photoshop. Unless this is a color picture, make sure it’s not tainted by vague color remnants, do Image > Mode > Grayscale.

.  > The actual picture fixing begins. It relies on

.  .  (a) Filters > Blur > Surface Blur. This smoothens, makes even, the surfaces, this is like magic ! It can get rid of scanning or printing defects in a wonderful way.
I usually have Radius = 5 and Treshold = 5 too. To increase the effects if needed, leave the Radius alone and increase the Threshold. But be careful, a too strong Surface Blur eats away at thin lines (like blushing cheeks, or around the eyes), so double-check you’re not killing image information, that wouldn’t be worth it. Better do two times in a row a Surface Blur, rather than do a single bigger Surface Blur that will damage your picture.

.  .  (b) Image > Adjustments > Levels. Usually, my rule is that areas supposed to be black must be made to be black instead of grey, and I sometimes adjust a bit also the midtones.
Toy around with those two tools, check and uncheck the Preview button, this is self-learning ^^

.  .  better do several operations with weak settings than one operation with strong settings. In Umekichi’s Deceitful Lips, I did SB, Levels, SB, Levels, for instance, I felt a SB provided different improved surfaces after a first levels correction.

.  > When you think you fixed the picture correctly, save it (control-S), and compare the “fixed” picture with the original picture.
You think you made a good job ? Great, let’s make it on all the pictures !

.  > Do again a copy of the unretouched picture, open it again in photoshop. You’re going to do the same fixing as before, but this time photoshop will register how you’re doing it, in order to be able to repeat the operation later.

.  > Press Alt-F9, in order to create an “action”, a list of operations to run automatically on every picture.

.  > In that Actions window, bottom right, on the left of the recycle bin icon, click the “new action” button. Photoshop starts registering. Do your fixing as previously. Save (control-S). Close the image (control-W). Click the “stop recording” square icon in the Actions window.

.  > Finally, in photoshop, do File > Automate > Batch, your latest saved Action will be automatically chosen, and then you specify the folder with the images to fix (do that on a copied folder, not on the original pics, you’ll need to compare if you didn’t screw up later ^^).
.  Run the Batch processing with the default settings otherwise. The pictures are reprocessed, saved, and closed, one after the other.

Check various resulting pics against their originals to make sure you didn’t screw up with too strong settings, also to make sure your picture viewer gives the same image results as in Photoshop.

And voilą, you’re done, you have your retouched version :)

Of course, as I wrote, there must be hundreds of different ways to fix pictures, depending on what fixing they need, and better ways than mine in the present situation, I don’t want to pretend I’m a guru (lol, I wouldn’t convince anyone ^^).
But I trust this simple method DOES work wonders and could, for you guys, out there on the other side of the internet tubes, help you with the grayscale hentai mangas we love so much :)