ipad/safari: White blocks over graphic novel

[badbob001]

When viewing a specific azw3-sourced graphic novel on ipad/safari, there are white rectangles covering each page. My guess is that the white rectangles indicate clickable panels to show a close-up of that panel. What can be done to get those books to be readable? Looking at the same book from chrome/windows doesn't show the rectangles nor are the panels clickable.

[kovidgoyal]

No clue, try converting it to a PDF sized for you phone screen.

[badbob001]

Originally Posted by kovidgoyal

No clue, try converting it to a PDF sized for you phone screen.

It's unclear what the server does when it transfers content to be viewable by the target browser. I guess it must know what device is connected based on maybe user agent? If I pre-create a pdf version, that will influence which source version the server will use for converting to the browser view?

Nothing I can do to prevent the content server from trying to convert the "Panel View" feature of the source book?

[kovidgoyal]

The content server does not do any conversion unless you ask it to, via the conversion button. And you should view the resulting PDF in the devices native PDF viewer, not the calibre browser viewer.

[badbob001]

Originally Posted by kovidgoyal

The content server does not do any conversion unless you ask it to, via the conversion button. And you should view the resulting PDF in the devices native PDF viewer, not the calibre browser viewer.

I don't mean conversion in the sense that a new format is stored on the library. The content server must be creating a temporary version that is viewable by the target browser. I guess it would be similar to how viewing from the gui temporarily renders the book to be usable by the calibre e-book viewer app. I can't seem to find a way to influence this temporary conversion.

From the gui e-book viewer, the panels are not clickable but every other page is white, which may be another symptom of the book's panel view format.

[kovidgoyal]

There is nothing to influence there. Its not a conversion but an extraction of the input documents contents in HTML form.

[kovidgoyal]

If you dont want to go the PDF route, then use the unpack book tool in calibre to extract all the images from the book, then zip them up into a CBZ file and view that, it wont have any of these artifacts.

[badbob001]

Originally Posted by kovidgoyal

There is nothing to influence there. Its not a conversion but an extraction of the input documents contents in HTML form.

I'm still confused. "Extraction" sound like you just "unzip" the ebook and lets the viewer see that content raw. But then you say "in HTML form", which implies that the content is either converted to HTML or at least re-wrapped within HTML.

There must be more to the viewer than just viewing the raw ebook content (which is usually based on HTML anyway). The viewer can control how many pages to show on screen. Depending on the browser used, the viewer may show "Loading next section". The viewer seems to recognize which browsers support full screen or not. I want to know if there is a way to manually determine or override some of these automatic settings? Since you don't directly test with ios anymore, perhaps some of these settings don't work as reliably anymore?

[kovidgoyal]

Most ebook formats are html internally, so the viewer just extracts that html. And of course there is more to the viewer than just extracting the HTML. The point I was making was that your white blocks issue is unlikely to be caused by the extract html step. If you want to experiment further you will need to run calibre from source, which is very easy, https://manual.calibre-ebook.com/develop.html

The viewer code is mostly in src/pyj/read_book and src/calibre/srv/render_book

[badbob001]

I finally figured out why the white blocks appear for some viewers and not others. The panel views are normally clear but if I override the page's colors, the blocks will match the override color!