2 questions this time:

1.I saw Genuine Fractals(Photoshop Add-on) a few days ago and just wonder if I can use it to decrease the size of my manga collection. (First resize images to a smaller scale--->smaller size, good for download, upload and transport; then use genuine fractals to enlarge for reading. How is the quality of the enlarged image then?)

2. Another way is to change the file format from ordinary image extension to Scalable Vector Graphics (SVG) file format.(I'm currently using Inkscape) Is it possible?

its cold down here fam ~

Too much hassle. Scanlators have been going up in size because they can. Internet connections are faster, storage is cheaper and good quality scanners are available. I personally would not have the patience to separately unpack chapters, apply a photoshop filter on each page and then re-pack, every single time I wanted to read something.

As far as I know there is also no perfect automatic vector graphics converter. That means you'll be spending lots of time tracing the pages of your comics. Not to mention what to do with badly cleaned/edited pages, they're all washed out grey, tilted and poorly typeset because of inexperienced editors, they'll need even more time.

Also you'd have altered the release in such a way that it's not really ok to share it anymore.

Quote from havoccc

Too much hassle. Scanlators have been going up in size because they can. Internet connections are faster, storage is cheaper and good quality scanners are available. I personally would not have the patience to separately unpack chapters, apply a photoshop filter on each page and then re-pack, every single time I wanted to read something.

As far as I know there is also no perfect automatic vector graphics converter. That means you'll be spending lots of time tracing the pages of your comics. Not to mention what to do with badly cleaned/edited pages, they're all washed out grey, tilted and poorly typeset because of inexperienced editors, they'll need even more time.

Also you'd have altered the release in such a way that it's not really ok to share it anymore.

I understand your point. Though I think .svg will be a good replacement in the future since they are really small in size(I try converting some images and they are about 2KB) and can be enlarged without losing much quality.

its cold down here fam ~

I tried it myself, that was indeed small, very very small... too small in fact. After some experimenting and reading about tracing in Inkscape, which is what you will have to do to have it actually vectorised.

The 2kb file is not right, it's just a link to the original image, try moving or renaming the original page you saved as .svg and you shouldn't be able to view the .svg anymore.

Here's some samples with two different vectorising/tracing methods in Inkscape:
pic1 PNG 215 kb
pic1 SVG with 8 layers brightness steps 8.9 mb (!!!)

pic2 PNG 186 kb
pic2 SVG with some ~0.500 brightness cutoff 1 mb
zoom comparison

sorry

It might be possible to squeeze it further if you start doing it manually, maybe there are some tricks, I don't know this is unfamiliar territory for me.