New servers and file optimisation request!

[vigorousjammer]

I've always exported to PNG-8 for nay greyscale pages ever since I've started getting serious about scanlation, it's just a no-brainer and every scanlation group should be doing this for greyscale pages.
Over the past year or so, I've started using pingo on all of the chapters I upload, too, and it's fantastic. Really advisable for any and every scanlation group.

As for color pages, I've went back and forth on my methodology... unsure if I should export them as 24-bit JPG or 24-bit PNG. On one hand, full color PNG files are larger, but you can avoid jpg artifacts and it's typically only for 3-5 pages, so the file size increase is usually somewhat negligible. On the other hand, there usually aren't very many jpg artifacts introduced if you export at the highest jpg quality, and they mostly get hidden by the colors, too, so maybe decreasing the file size by 3 or 4 megabytes is worth it.

 

[pikokola]

@ixlone
While we're at it, why not also screen group credit pages.
For example, I swear I won't bother you again chp. 7 by puni have 5-ishMBs credit page while the chapter itself is only around 25-ishMbs.
LH usually have 2~3 credit pages in one chapter.
some group have unoptimized coloured credit pages which go over 2 times of the average of its chapter pages filesize (i.e 2MBs credit page while the average filesize is merely 750KBs-1MBs. - for low-speed user it's pretty disheartening when you wait for a clearly longer time expecting new pages only to find that it's just a credit page.)

I'm not saying that they shouldn't have one, but having one which took over more than 10% of total chapter filesize or big enough to host a lossy 3 minutes audio files or go past the average filesize for the said chapter or (insert another overkill credit page reason) is a bit overkill.
and no, I am not especially calling to those group, I just picked them at random from my downloaded manga folders. I believe there are some which is worse, something with 10+MBs credit page (I'm not joking, I remember mentioning them on one of their release chapter comment, but I can't remember which series or group was it.)

I know it's not MDs place to police the scanlation, moreover to strip those credit page would be heresy. But, every time they upload stuff with "bloated" credit page, could you just take a moment to look them in the eyes and say "Dude..."

 

[MegaXL]

Wait, is this why the page loading has been giving me issues lately?!?

 

[lordmage]

@pikokola my experience is the groups with delay policies that force you to wait or read on there site are the ones your speaking off. the delay on load maybe for those site readers so AD'S display longer i personally think MD should enforce a file size limit on uploaders that is to say unless source breaks a chapter then all the chapter should fall within a set group of size based on the total pages. Title pages and what not are fine for me if the release loads under normal experiences but if i feel im on dial up when i am not then It should fall outside those MD limits if they enforced it. after all MD is by choice for reader and uploader alike but the server is designed to help the media get to the reader so a file size limit would serve the purpose.

 

[lrb]

Is there something I can do to help? I'd be happy to donate some of my computer's time to optimize a bunch of images for you.

 

[Rugid]

@MegaXL

Wait, is this why the page loading has been giving me issues lately?!?

Probably one of the reasons. Because when hundreds of people simultaneously trying to read thing like https://mangadex.org/chapter/895280 where each page is 2-3 MB, obviously site and their computers can experience slowdown, no to mention that each page will be downloading many times slower.

@Santiasan
I couldn't understand what are you doing at all, but just in case: when saving files in photoshop, find and uncheck "convert to sRGB" option. It messing with colors in grayscale images.

 

[Shirobane]

@pikokola
> LH usually have 2~3 credit pages in one chapter.

How about 4 extra pages, for a 4 page chapter? https://mangadex.org/chapter/756196/1
That’s a credit page with their logo, the LN cover for some reason and a plea for donations. A separate page with just their logo. Another page with their logo again but in b&w. Another page with another plea for donations. Dude.

The magazine serialised version of that manga bundles a handful of chapters because they’re so small...

 

[Lyros]

I didn't read the thread and here's my 2 cents.

Since you're optimizing all your pngs, you might as well losslessly optimize them on upload. Here's two more pieces of software that may or may not have been already mentioned:
Optipng: http://optipng.sourceforge.net/
Oxipng: https://github.com/shssoichiro/oxipng

If you want to get on the WebP meme, but need to consider apple losers and internet explorer, mod_pagespeed claims to serve webp only to browsers that support it without "modifications to existing content or workflow."
https://en.wikipedia.org/wiki/Google_PageSpeed_Tools#PageSpeed_Module
https://developers.google.com/speed/pagespeed/module

Another potential optimization to consider: Image de-duplication. You take the hash of the image data, you can detect when credit pages are the same, and just reference said credit page instead of storing it as a separate file. The benefits are two-fold: you don't store redundant images and you transfer less data over the wire when users don't have to redownload the same image, instead pulling it from their browser cache. The downside is higher server load when images are uploaded and the benefits might be negligible, because not all groups re-use credit pages.

 

[kuyukotto]

I wish there was an option to opt for very compressed images so I can save on mobile data. You can implement this retroactively and apply alt compress images only for top titles. I think you can save enormous bandwidth. I don't think users reading on their tablets or phones would really complain about quality so long as the text readable. Honestly MD's speed here in asia is horrible so lossy images is much preferred over not being to read.

 

[Santiasan]

@Rugid thanks for your tips, I will try it later^.^

 

[Santiasan]

@moozooh
Before that, I think we have to clear up the misunderstanding that happened first ... First, I don't do scanlations and only do translations. Secondly, if I need raw manhwa, I do screenshots (png) and for the manga, I take from the English translator (because in my city there are only small bookstores that only sell Japanese comics like Doraemon, Naruto, and Sinchan: v). You can see the original image in this link (the original image is PNG) https://drive.google.com/open?id=1iH_hcV0JvG3lgVuX5VyDlgv7mDXiv-0y . And the Image save in JPG (or you can call it, compress with JPG) https://drive.google.com/open?id=1X7wVkpxPNbxdzTL7JNENs_vuG77isAuE . and the export image as PNG is in this link (without convert to sRGB and with smaller file 8-bit) https://drive.google.com/open?id=1sYNz5q5fv9oYLQdRvNsmKUEbFE0-jbxq (you can see the different color more clear at the eyes). If I'm mess up something please tell me^.^ because I'm still learning ~~ And I'm sorry if the raw was blurry >.< I'm searching in the internet to how to make the screenshot more quality but I can't find the tips T.T

 

[iDeSmI]

If you are on Linux,

[b]pngquant[/b]

https://pngquant.org/ is the best for size reduction.

 

[BzzBzz]

> If you are on Linux, pngquant https://pngquant.org/ is the best for size reduction.

Yea… lossy compression of PNG images… why don't you just jpeg it?

 

[iDeSmI]

@BzzBzz There's the option

--quality=100

.
We're talking about high rates of reduction here, optipng and pngcrush are optimal but can't provide that.

 

[Holo]

@kuyukotto
Check your settings

 

[Kamikoto]

Very helpful, thanks for the guide.

EDIT: Does anyone know how to batch export PNG-8 with Photoshop or some kind of workaround? Seems like that feature isn't supported, which sucks.

 

[oOolOlIlOvEr69oOo]

Not sure if it's been mentioned in the thread, but I didn't notice there was an option to include "None" for metadata for Photoshop's Save For Web when I initially looked, so that should be something to check off when not using one of the suggested programs.

@Kamikoto

In CS6, I could batch export the same way I batch exported previously, with a caveat that it doesn't respect the "Override Save As" for the folder that it goes to.
I just start recording a macro, perform the Save For Web, then Automate it on the folder. Here's my awful video on this with Save As if you didn't use a macro before, but *almost* this same process, except you should choose some folder that you can easily script out moving the files out of the target since Save For Web doesn't seem to respect this option?

Just working around it by moving everything a target folder I use for it to the actual folder I want for now.
(In shell, while in the exported folder, mv *.png /path/to/target/folder or use the -t flag for the target folder while specifying the path to glob on)
(move might work in Windows cmd, not sure about it's globbing capabilities with *)
(oh wait you can just do it with ctrl+a in a gui file explorer if they're the only thing in the folder I guess)

 

[Kamikoto]

@oOolOlIlOvEr69oOo Thank you 😄. Weird that Save For Web works but not Export As.

 

[Rugid]

@Santiasan
If I get it right, then what you're doing is incredibly stupid. Who saving full color images, especially the ones which were destroyed by low jpg compression beforehand, with only 256 colors (i.e. png-8)? You just killing them even more. Save them in jpg with 92 quality, they won't get any worse than they already are. Use 8 bit png only for black&white images.


@Kamikoto

Does anyone know how to batch export PNG-8 with Photoshop or some kind of workaround?

0. Start photoshop.
1. Open scan.
2. Start a new action.
3. Press Alt + Shift + Ctrl + S.
4. Choose png-8, then number of colors you want, etc. Don't forget to uncheck "convert to sRGB" and disable metadata.
5. Save (choose where you want all you saved scans go in the future).
6. Close the scan without saving and stop action recording.
Now you can go File -> Automate -> Batch, choose the action you recorded, choose the place where the scans you what to process are (I recommend to make permanent place for them, like C:\PS_batch and place scans there when you need), and then OK and wait.

p.s. Also, when/after making a new action, you can choose which button to press to start it. For example, F8. Then, when you want to save scan in png8 like above, you just press F8. Though you might want to not close the scan after saving png (you can switch individual steps in action on and off, btw), just in case. 😅

 

[Ou_Ki]

@Kamikoto just use Releasify by illiteracy (Illuminati Manga): https://illuminati-manga.com/illiteracy/releasify/

It automatically opens Photoshop and saves the images using PNG-8 (you can change the settings too) for grayscale images and JPEG for RGB images (you can change the quality too). It even allows zipping the images after saving them.

(by the way, illiteracy is the author of Typesetterer too, for those who use it)