Converting jpeg right-to-left landscape pages to EPUB

HumbleDumbbell · 11-16-2020, 01:12 AM

Hi everyone,

I did a bit of digging, but couldn't find anything on this. I am not sure if it's an issue or my lack of understanding how Calibre works.

Basically I have a cbr file with a bunch of jpeg files inside that I am converting to EPUB. Each jpeg file is a landscape page (2 pages in one jpeg) that are meant to be read right to left (the right page first, the left page second). Calibre splits the landscape file into two pages/pictures, which I like, but it uses the left half as the first page and the right half as the second.

Question: How can I tell Calibre to order the pages correctly (either during conversion or after) - using the right half of the page as the first page in the pair?

Manually rearranging pages (drag and drop is all I know) in the editor is not an option due to a large number of pages.

Thank you in advance.

kovidgoyal · 11-16-2020, 01:25 AM

Look under the comic input section of the conversion dialog

HumbleDumbbell · 11-16-2020, 02:13 AM

Oh, thank you for the tip. I actually saw it in the manual, but couldn't find it anywhere in the conversion wizard. Now I realize it's because I got lazy and was trying to "reconvert" my existing epubs and looking for a way to tell it to flip the pages for me. So it seems I'll have to reconvert the whole stack now. Or is there an easier way?

kovidgoyal · 11-16-2020, 02:31 AM

Sure set the option in preferences->Input options and use bulk conversion, unchecking the box to use saved conversion settings. Remeber to delete the epub formats first so the comic is used as the input surce.

HumbleDumbbell · 11-16-2020, 05:06 AM

Thank you. I am not sure I did what you meant, but I just deleted the epubs and converted each item using individual conversion (I also noticed there is no comic input in bulk conversion, which is why I missed it the whole time). It worked.

BetterRed · 11-16-2020, 04:49 PM

Quote:

Originally Posted by HumbleDumbbell

Thank you. I am not sure I did what you meant, but I just deleted the epubs and converted each item using individual conversion (I also noticed there is no comic input in bulk conversion, which is why I missed it the whole time). It worked.

IIRC: bulk conversion inputs whichever format it finds that is highest on the Preferences->Behaviour->Preferred input format order: list.

If you promote comic formats (i.e CBZ, CBR and CBC) in that list to be higher than EPUB than it should convert those formats without needing to remove existing EPUBs.

BR

HumbleDumbbell · 11-17-2020, 07:36 PM

Thanks, BR. I figured it out. =)

HumbleDumbbell · 11-17-2020, 09:09 PM

Apologies for double posting. I have just run into another challenge.

I am trying to convert the same right-to-left landscape files into pdf. I want to preserve the original picture quality, but it seems I have to make a choice between keeping that quality by disabling comic processing or having Calibre do the splitting of the landscape pages and aligning them right to left.

Basically, when I enable right-to-left, I lose quality. When I turn on Disable comic processing, the pages do get split into two, but each page, rather than being a separate image, contains 1 image repeated three times left to right. with huge blank space above and below the picture strip (basically, it fits 3 same images to the width of the page leaving blank spaces above and below).

Advice would yet again be much appreciated)

kovidgoyal · 11-17-2020, 11:56 PM

Just use the tablet output profile and images will not be resized.

HumbleDumbbell · 11-18-2020, 12:09 AM

Quote:

Originally Posted by kovidgoyal

Just use the tablet output profile and images will not be resized.

Hm, I must say it doesn't help. I actually have to admit it's not just a problem of my landscape pages. A few other files (I convert CBR to PDF, sorry I forgot to mention it) have single pages inside them, so I do not need to split them. I disable the comic processing to get the best quality, and I still get that triple image on one page issue. I tried both Default and Tablet profiles.

It doesn't happen all the time with every CBR archive I have, so I don't understand what might be causing it.

It does seem to happen for certain series (say, manga A has 10 volumes in CBR and manga B has another 10 - Manga A may have this problem while manga B doesn't). Could it be something in the archives?

kovidgoyal · 11-18-2020, 12:26 AM

Hard to say, opena bug report and attach the problematic cbr along with a description of th eissue.

HumbleDumbbell · 11-18-2020, 12:56 AM

Okay, it looks I have figured it out. Basically, the settings set in the preferences were interfering with it. I set Disable comic processing in the Preferences, and forgot to uncheck to use the saved settings (I guess that's what it does?).

Anyway, I basically got lost in all the settings, which means it works as it should.

Note to others: disabling comic processing messes with cbr to pdf conversion but does not interfere with cbr to epub.

Thank you for your help. I may be back with more silly questions.

11-16-2020, 01:12 AM	#1
HumbleDumbbell Member Posts: 20 Karma: 10 Join Date: Nov 2020 Device: Likebook Alita	Converting jpeg right-to-left landscape pages to EPUB Hi everyone, I did a bit of digging, but couldn't find anything on this. I am not sure if it's an issue or my lack of understanding how Calibre works. Basically I have a cbr file with a bunch of jpeg files inside that I am converting to EPUB. Each jpeg file is a landscape page (2 pages in one jpeg) that are meant to be read right to left (the right page first, the left page second). Calibre splits the landscape file into two pages/pictures, which I like, but it uses the left half as the first page and the right half as the second. Question: How can I tell Calibre to order the pages correctly (either during conversion or after) - using the right half of the page as the first page in the pair? Manually rearranging pages (drag and drop is all I know) in the editor is not an option due to a large number of pages. Thank you in advance.

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11-16-2020, 01:25 AM	#2
kovidgoyal creator of calibre Posts: 43,871 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	Look under the comic input section of the conversion dialog

11-16-2020, 02:13 AM	#3
HumbleDumbbell Member Posts: 20 Karma: 10 Join Date: Nov 2020 Device: Likebook Alita	Oh, thank you for the tip. I actually saw it in the manual, but couldn't find it anywhere in the conversion wizard. Now I realize it's because I got lazy and was trying to "reconvert" my existing epubs and looking for a way to tell it to flip the pages for me. So it seems I'll have to reconvert the whole stack now. Or is there an easier way?

11-16-2020, 02:31 AM	#4
kovidgoyal creator of calibre Posts: 43,871 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	Sure set the option in preferences->Input options and use bulk conversion, unchecking the box to use saved conversion settings. Remeber to delete the epub formats first so the comic is used as the input surce.

11-16-2020, 05:06 AM	#5
HumbleDumbbell Member Posts: 20 Karma: 10 Join Date: Nov 2020 Device: Likebook Alita	Thank you. I am not sure I did what you meant, but I just deleted the epubs and converted each item using individual conversion (I also noticed there is no comic input in bulk conversion, which is why I missed it the whole time). It worked.

11-17-2020, 07:36 PM	#7
HumbleDumbbell Member Posts: 20 Karma: 10 Join Date: Nov 2020 Device: Likebook Alita	Thanks, BR. I figured it out. =)

11-17-2020, 09:09 PM	#8
HumbleDumbbell Member Posts: 20 Karma: 10 Join Date: Nov 2020 Device: Likebook Alita	Apologies for double posting. I have just run into another challenge. I am trying to convert the same right-to-left landscape files into pdf. I want to preserve the original picture quality, but it seems I have to make a choice between keeping that quality by disabling comic processing or having Calibre do the splitting of the landscape pages and aligning them right to left. Basically, when I enable right-to-left, I lose quality. When I turn on Disable comic processing, the pages do get split into two, but each page, rather than being a separate image, contains 1 image repeated three times left to right. with huge blank space above and below the picture strip (basically, it fits 3 same images to the width of the page leaving blank spaces above and below). Advice would yet again be much appreciated)

11-17-2020, 11:56 PM	#9
kovidgoyal creator of calibre Posts: 43,871 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	Just use the tablet output profile and images will not be resized.

11-18-2020, 12:26 AM	#11
kovidgoyal creator of calibre Posts: 43,871 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	Hard to say, opena bug report and attach the problematic cbr along with a description of th eissue.

11-18-2020, 12:56 AM	#12
HumbleDumbbell Member Posts: 20 Karma: 10 Join Date: Nov 2020 Device: Likebook Alita	Okay, it looks I have figured it out. Basically, the settings set in the preferences were interfering with it. I set Disable comic processing in the Preferences, and forgot to uncheck to use the saved settings (I guess that's what it does?). Anyway, I basically got lost in all the settings, which means it works as it should. Note to others: disabling comic processing messes with cbr to pdf conversion but does not interfere with cbr to epub. Thank you for your help. I may be back with more silly questions.