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tomsem · 09-05-2024, 09:57 PM

A couple of issues with KFX->PDF (specifically with KFX manga/comic format):

1: 'Binding' document property (what Acrobat calls it) should reflect page reading direction of source (e.g. for manga/japanese it should be right-to-left).

Currently it assumes left-to-right page direction, but that messes with PDF books that are laid out for right-to-left page order, such as manga: 2 page spreads will have left and right pages reversed.

I happen to have Acrobat Pro and am able to change it, but Acrobat Reader apparently will not let you do this (option in Advanced document properties is disabled).

It is sorta odd that PDF viewers do not typically let you change it, or even pay attention to it if it is set (Apple Books does not, PDF Expert does not). In such cases the only recourse seems to be to avoid 2-page layout.

It looks like something you can set with PyPDF in ViewerPreferences dictionary:

https://pypdf.readthedocs.io/en/stab...s.html#example

It would be too much to expect every PDF viewer to pay attention to this, but at least Adobe Reader does. And of course it is only an issue in 2-page layout.

2: This is a bit more involved: there are sometimes images with 2-page spreads, twice the width of non-spread images. Conversion to PDF writes out a single page, which of course does not 'spread' in 2 page layout, and only consumes one page instead of two, so it's complicated to add PDF page labels that correspond to what may be in the image.

The first workaround I did for this was to rotate the spread 90 deg clockwise and insert a blank page before or after the spread (depending on page reading direction) forming a sort of pseudo spread that also preserves expected left/right ness of the 'single' pages and normal page numbering.

But the 'correct' thing is to split the image in half and make two pages instead of just one, which is how I am fixing things up now.

My method is not particularly portable or automate-able: I happen to have a page splitter script for Acrobat Pro, which I apply to extracted spread pages, and then I replace the existing spread pages with the split spread pages (again paying attention to page reading order). Often a spread page is a target of a PDF bookmark so I have to fix that too. But it doesn't take that much time. f

I'm not sure how I'd do it without the page splitter script. Even image split-in-half scripts are typically one image at a time. Kindle Comic Converter probably: it can split 'wide' images that it finds and output to CBZ, and then you could make a PDF out of that. So then KFX->CBZ would be first step.

But 'it would be nice' if From KFX->PDF just handled it.

Note that none of this applies to Print Replica KFX: it does not support 2-page layout (maybe someday, one can only hope).

The other fixed layout format (not sure how you create or publish one -- InDesign and submit FXL ePub probably? Kindle Create doesn't do it.) are KF8 fixed-layout that have text in addition to images and unlike Print Replica, support facing pages and have spreads. I think KindleUnpack coverts these to ePub FXL pretty well, and I think calibre can convert these to PDF pretty well or did last time I tried it. In any case, not anything KFX Input has any role in.

09-05-2024, 09:57 PM	#751
tomsem Grand Sorcerer Posts: 6,951 Karma: 27060153 Join Date: Apr 2009 Location: USA Device: iPhone 15PM, Kindle Scribe, iPad mini 6, PocketBook InkPad Color 3	A couple of issues with KFX->PDF (specifically with KFX manga/comic format): 1: 'Binding' document property (what Acrobat calls it) should reflect page reading direction of source (e.g. for manga/japanese it should be right-to-left). Currently it assumes left-to-right page direction, but that messes with PDF books that are laid out for right-to-left page order, such as manga: 2 page spreads will have left and right pages reversed. I happen to have Acrobat Pro and am able to change it, but Acrobat Reader apparently will not let you do this (option in Advanced document properties is disabled). It is sorta odd that PDF viewers do not typically let you change it, or even pay attention to it if it is set (Apple Books does not, PDF Expert does not). In such cases the only recourse seems to be to avoid 2-page layout. It looks like something you can set with PyPDF in ViewerPreferences dictionary: https://pypdf.readthedocs.io/en/stab...s.html#example It would be too much to expect every PDF viewer to pay attention to this, but at least Adobe Reader does. And of course it is only an issue in 2-page layout. 2: This is a bit more involved: there are sometimes images with 2-page spreads, twice the width of non-spread images. Conversion to PDF writes out a single page, which of course does not 'spread' in 2 page layout, and only consumes one page instead of two, so it's complicated to add PDF page labels that correspond to what may be in the image. The first workaround I did for this was to rotate the spread 90 deg clockwise and insert a blank page before or after the spread (depending on page reading direction) forming a sort of pseudo spread that also preserves expected left/right ness of the 'single' pages and normal page numbering. But the 'correct' thing is to split the image in half and make two pages instead of just one, which is how I am fixing things up now. My method is not particularly portable or automate-able: I happen to have a page splitter script for Acrobat Pro, which I apply to extracted spread pages, and then I replace the existing spread pages with the split spread pages (again paying attention to page reading order). Often a spread page is a target of a PDF bookmark so I have to fix that too. But it doesn't take that much time. f I'm not sure how I'd do it without the page splitter script. Even image split-in-half scripts are typically one image at a time. Kindle Comic Converter probably: it can split 'wide' images that it finds and output to CBZ, and then you could make a PDF out of that. So then KFX->CBZ would be first step. But 'it would be nice' if From KFX->PDF just handled it. Note that none of this applies to Print Replica KFX: it does not support 2-page layout (maybe someday, one can only hope). The other fixed layout format (not sure how you create or publish one -- InDesign and submit FXL ePub probably? Kindle Create doesn't do it.) are KF8 fixed-layout that have text in addition to images and unlike Print Replica, support facing pages and have spreads. I think KindleUnpack coverts these to ePub FXL pretty well, and I think calibre can convert these to PDF pretty well or did last time I tried it. In any case, not anything KFX Input has any role in. Last edited by tomsem; 09-05-2024 at 10:07 PM.