Show HN: eInk optimized manga with Kindle Comic Converter (+Kobo/ReMarkable)
45 comments
·May 7, 2025sabslikesobs
Super cool. Thanks for maintaining this.
I read manga extensively on my Kobo Forma with koreader. I wrote a script with imagemagick to scale, trim, adjust contrast, map to 16 colors, dither, and repack, all without me having to interact with it... something I'm hoping to open-source sometime, although it's very specific to my use case.
seam_carver
Can't wait to see it when you open source
shiandow
Are there any plans to integrate this with calibre? Or is it integrated already?
The combination would be quite powerful IMHO.
seam_carver
I personally just do boring USB transfer of files instead. Users have reported issues with Calibre modifying KCC files and breaking the formatting, fixed layout books like comics/manga are different than normal reflowable ebooks.
I only use Calibre for normal ebooks.
Maybe in the future, KCC has command line versions as well. It's all Python.
shiandow
I think calibre plugins are all python, in theory that should work. In practice, who knows.
carlosjobim
How do you do USB transfers without Calibre?
seam_carver
You just drag and drop the mobi file into the documents folder on the Kindle.
If you are on macOS, you need the Amazon USB File Manager app to do that on newer MTP based Kindles. Older kindles just used ordinary USB mass storage protocol. Link in readme.
goosedragons
Is it weird that I kind of want ePub to ePub support? I have many not Kobo compatible comics/manga from places like Humble Bundle that I need to fix. Ideally I'd like to keep metadata + reading direction and perhaps the table of contents. I suppose I could script something that unzips 'em and then processes them....
seam_carver
Yea, that's true, but it's not as simple as just unzipping the epub, I've found sometimes that the pages aren't named in a sorted order, the order is defined in one of the opf file.
seam_carver
There's a FAQ in the readme about Humble Bundle. I've found that the PDF source is the absolute best quality with the least amount of resizing artifacts/moire compared to epub.
goosedragons
Yeah, not all the bundles offer books as PDF either. And they're not all from Humble Bundle.
romaaeterna
I have found that the trick to getting optimized kindle display with imagemagick tools is to process pages as individual images, and then use a tool like img2pdf to quickly stitch them together into a pdf file as a simple archive.
seam_carver
The kindle pdf renderer is much slower than the mobi/azw3 renderer and isn’t full screen.
joshdavham
Hey thanks for posting this! I'll defintitely check it out.
Also, as a somewhat unrelated question: how would you recommend someone go about learning pyqt? I've looked into it briefly and am not really sure what the recommended resources are for this framework.
seam_carver
This project was my first exposure to Qt, and I just read the official docs.
joshdavham
Are these the docs you're referring to? https://doc.qt.io/qtforpython-6/
seam_carver
Yes, but be aware I didn't write this from scratch, I ported pre-existing qt5 code to qt6. and made modifications to the UI
tecleandor
Looks nice! I'm gonna test it!
Feature idea (that I think it doesn't have): a gamma/palette sampler. Takes one page of the source, and generates an output with multiple pages, all for the same source page, but each one using a different gamma and/or palette option. Useful when the source is "difficult" (weird shading, colors...) or it's an unknown device, to find the best configuration.
seam_carver
I usually leave it on auto or disable gamma by setting it to 1.0
ksynwa
Normally I just use Koreader on my Kobo. It crops out the margin automatically which is necessary for the small screen. Then I play with the contrast to make the blacks look like they would on paper. Hate asking people to sell their hard work to me but is there something else that this tool does to make the experience even better?
seam_carver
The main audience of KCC doesn't have access to the powerful features of koreader, but filesize optimization is pretty nice and can get filesizes down significantly.
Cropping whitespace between panels (not just margins on the edge) is also cool. And page number cropping.
7jjjjjjj
This is a huge deal for me, last time I wanted to read manga on my kindle the filesize is what killed the idea.
MilanTodorovic
I got around this with Pillow and Python by reducing the image quality to like 20% which in my case didn't have any compromises, but reduced the image size quite substantially. Then I repackaged the images back into cbz and used KCC to make a proper file. As a disclaimer, I have done it only with the Kaiji Ultimate Survivor series to be able to fit the entire manga on my Kindle PW3 with 4GB of storage (I already used up like 1.5GB). Kaiji has less complex drawings, which most certainly plays a role.
null
looperhacks
This sounds great!
I never got to reading manga on my Paperwhite 4(?) because the scaling made the text terrible to read (that was with KOReader a few years ago). Does this tool handle this better?
seam_carver
A recent feature I implemented a few weeks ago was virtual panel view.
You can enable it in the Kindle Aa menu.
You can double tap a corner to zoom into the corner in portrait mode 150% zoom.
Or you can turn the Kindle sideways to read half a page at a time.
and KCC scaling using the LANCOZ algorithm, which looks great.
roskelld
Bookmarking this for when I have some free time. It might get me back to finishing my read through of Berserk.
royaltjames
I just started this today and wow
sepositus
Has anyone tried this on a Remarkable? It always seemed like the perfect size for reading comic books/magna.
seam_carver
Considering how ReMarkable support was added by a community member, it probably looks great.
edit: added remarkable 1/2 sample file to link in other comment.
npteljes
Curious project! I'd love to check out the samples, but the links don't seem to be working in the README.
seam_carver
Oh... the sample links are all dead. They were made by previous KCC maintainer.
For now, here's some kindle scribe samples. The mobi can be usb transferred, the epub can be sent via Send to Kindle. They might look fine on other Kindles, let me know! Otherwise I can put up more samples.
https://www.mediafire.com/folder/ixh40veo6hrc5/kcc_samples
Edit: added more kindles/kobos/remarkable, lmk if I made any errors! only difference is resolution
Kindle Comic Converter optimizes comics and manga for eink readers like Kindle, Kobo, ReMarkable, and more. Pages display in fullscreen without margins, with proper fixed layout support. Its main feature is various optional image processing steps to look good on eink screens, which have different requirements than normal LCD screens. It also does filesize optimization by downscaling to your specific device's screen resolution, which can improve performance on underpowered ereaders. Supported input formats include folders/CBZ/CBR/PDF of JPG/PNG files and more. Supported output formats include MOBI/AZW3, EPUB, KEPUB, and CBZ.
Hey everyone! I'm the current maintainer of KCC since 2023, thanks for using it! I’ve been reading manga on Kindle ever since I got the big 9.7” Kindle DX from 2010 using mangle, and upgraded to the even bigger 10.2” Kindle Scribe 2022 using KCC.
The biggest contributions I've made to KCC are:
- added modern macOS support and removed homebrew requirement - ported code to run on native Apple silicon M1 chip and later for a 2x speed boost (qt5->qt6) - free open source windows codesign with SignPath - fixed Kindle Scribe support - and tons of other various features and bug fixes and developer friendly changes - created a legacy Windows 7 build with 300+ downloads…
The biggest community PRs were:
- huge 2x speed boosts due to various CPU/IO optimizations - Kobo/Remarkable support
Enjoy using KCC and let me know if you have any questions!