Introducing New tool: "Polish" Books - Page 8

Dchiplin · 05-27-2016, 06:26 PM

Has anyone reported an issue with polished books not loading onto their reader (Kobo Aura H2) in this case)?

What happens for me on my Kobo, is that on selecting the book, it is very slow to respond, and then I get a single page - blank with the exception of (sometimes) a very tiny image of the cover in the upper left corner and the title - nothing else - and the device is frozen.

I have tried to use the feature a number of times and have had to revert to converting my .ePUBs to be able to load my reader with books that contain updated covers, tags, comments, etc.

Most grateful if any suggestions.

JSWolf · 05-27-2016, 06:46 PM

Quote:

Originally Posted by Dchiplin

Has anyone reported an issue with polished books not loading onto their reader (Kobo Aura H2) in this case)?

What happens for me on my Kobo, is that on selecting the book, it is very slow to respond, and then I get a single page - blank with the exception of (sometimes) a very tiny image of the cover in the upper left corner and the title - nothing else - and the device is frozen.

I have tried to use the feature a number of times and have had to revert to converting my .ePUBs to be able to load my reader with books that contain updated covers, tags, comments, etc.

Most grateful if any suggestions.

Are you polishing kepub and not ePub?

Dchiplin · 06-05-2016, 01:14 PM

No - ePub format.

eschwartz · 06-05-2016, 01:29 PM

Quote:

Originally Posted by Dchiplin

Has anyone reported an issue with polished books not loading onto their reader (Kobo Aura H2) in this case)?

What happens for me on my Kobo, is that on selecting the book, it is very slow to respond, and then I get a single page - blank with the exception of (sometimes) a very tiny image of the cover in the upper left corner and the title - nothing else - and the device is frozen.

I have tried to use the feature a number of times and have had to revert to converting my .ePUBs to be able to load my reader with books that contain updated covers, tags, comments, etc.

Most grateful if any suggestions.

Polish Books has several different things it can do. Which ones did you use?

Note that updating the metadata and covers is something which is done anyway by send-to-device (and FYI does not require reconverting!!!).
So it can't be just that, or ordinary sent books would have the same problem.

kovidgoyal · 06-05-2016, 09:26 PM

I doubt very much it has anything to do with Polish. Try sending the books without polishing and you will likely see the same behavior. An EPUB to EPUB conversion does lots of things to make EPUB files less likely to break on readers.

Dchiplin · 06-12-2016, 11:48 AM

OK, then it appears just as Kovid states that my problem is not with Polish and that I have a more fundamental issue or I am missing something (which is quite possible!!).

When I add a new book to my Calibre library, I always add or update metadata & replace cover, etc.

When I send the book to my Kobo without converting, the book on the device has no jacket page. However, cover art replacements are made.

Embedding does not add a jacket when book is sent to device.

Modifying does add a jacket when book is sent to device (of course sending the new .ePub).

Polishing seems to do something odd to the book (hence my original post).

Converting sends everything I changed and I have never (yet) had a quality issue with a converted book.

As well, the Kobo Utility “update metadata in device library” does not update the jacket data even though the message says it is updating.

I’d be grateful for any guidance on this as I currently have to remove book from device and resend a converted copy every time I clean-up the comments or other data.

kovidgoyal · 06-12-2016, 11:56 AM

I'm not sure I understand you. You say that you dont want to have to delete and resend the converted book every time you make changes. But you have to do that regardless of whether you use book polishing or converting. So, since converting works well for you, just use it.

BetterRed · 06-12-2016, 05:24 PM

@Dchiplin - in and of itself a jacket is not metadata; it's a regular 'page' whose content is derived from the metadata, which probably explains why Embed Metadata and Kobo Utility "update metadata in device library" don't update jackets.

FWIW - I use the Modify PI to refresh jackets in EPUBs. I use Modify rather than Polish because I also remove the cover and non-dc metadata elements.

BR

davidfor · 06-12-2016, 10:34 PM

Quote:

Originally Posted by Dchiplin

OK, then it appears just as Kovid states that my problem is not with Polish and that I have a more fundamental issue or I am missing something (which is quite possible!!).

When I add a new book to my Calibre library, I always add or update metadata & replace cover, etc.

When I send the book to my Kobo without converting, the book on the device has no jacket page. However, cover art replacements are made.

Embedding does not add a jacket when book is sent to device.

Modifying does add a jacket when book is sent to device (of course sending the new .ePub).

Polishing seems to do something odd to the book (hence my original post).

Converting sends everything I changed and I have never (yet) had a quality issue with a converted book.

As well, the Kobo Utility “update metadata in device library” does not update the jacket data even though the message says it is updating.

I’d be grateful for any guidance on this as I currently have to remove book from device and resend a converted copy every time I clean-up the comments or other data.

I'm confused. In another thread you have been reporting problems with the Kobo Utility "update metadata in device library". I assumed from that thread you were looking at the comments displayed on the details page on the device, not when opening the book. The plugin makes no changes to the actual books. It fiddles with metadata in the devices database. This is displayed in the lists and on the details page. An example of this is shown in the screen shot here.

If you were talking about the jacket that is displayed as a page in the book, the only way to see changes to it is to resend the book to the device. On the Kobo devices, you should delete and resend, but you can usually get away with resending the book so long as you don't the change the internal structure or ToC.

dxcore35 · 04-23-2020, 05:15 AM

Hello,

It is possible to implement this module: OPTIMAGE
https://github.com/sk-/optimage

The compression of images is amazing.

Here are benchmarks: https://optimage.app/benchmark

I don't have clue how internal calibre compression works, but I observe I can compress the picture further more. It will be huge size saver and big benefit for people with huge libraries.

kovidgoyal · 04-23-2020, 06:39 AM

calibre uses mozjpeg and optipng. Which is the same as optimge which is just a convenience wrapper.

dxcore35 · 04-24-2020, 02:55 AM

Interesting, so it is implemented already, nice!

1) Do you know why books containing PNG takes few hours to optimize in Polish plugin or in Book editor section? The same speed is directly in Optimage module, so it looks like bug in there.... For JPGs it take just few minutes / seconds.

2) Can you put compression option with percentage in Polish plugin?

kovidgoyal · 04-24-2020, 02:58 AM

The way optipng work is it tried to re-compress the PNG file repeatedly with different zlib settings, this is slow.

And no polish does only lossless compression, so there is no compression level. The maximum amout of lossless compression that is possible is done.

dxcore35 · 05-01-2020, 02:06 AM

I will not say it is slow, but that it is not usable at all - hour or more to compress 20 pictures?

Can you just convert them in JPG and compress it?
Or ignore compression of PNG?

kovidgoyal · 05-01-2020, 03:26 AM

converting to jpg involves data loss. And if you have a faster method of compressing PNG that works as well, do share.

04-23-2020, 05:15 AM	#115
dxcore35 Member Posts: 22 Karma: 10 Join Date: Mar 2018 Device: Kindle Voyage	Implement Optimage module (extreme lossless compression) Hello, It is possible to implement this module: OPTIMAGE https://github.com/sk-/optimage The compression of images is amazing. Here are benchmarks: https://optimage.app/benchmark I don't have clue how internal calibre compression works, but I observe I can compress the picture further more. It will be huge size saver and big benefit for people with huge libraries. Last edited by dxcore35; 04-23-2020 at 05:21 AM.

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05-27-2016, 06:26 PM	#106
Dchiplin deb_oh_canada Posts: 34 Karma: 10 Join Date: Sep 2011 Location: North of 50° Device: Kobo Forma & Aura One & iPad Mini Retina	Has anyone reported an issue with polished books not loading onto their reader (Kobo Aura H2) in this case)? What happens for me on my Kobo, is that on selecting the book, it is very slow to respond, and then I get a single page - blank with the exception of (sometimes) a very tiny image of the cover in the upper left corner and the title - nothing else - and the device is frozen. I have tried to use the feature a number of times and have had to revert to converting my .ePUBs to be able to load my reader with books that contain updated covers, tags, comments, etc. Most grateful if any suggestions.

06-05-2016, 01:14 PM	#108
Dchiplin deb_oh_canada Posts: 34 Karma: 10 Join Date: Sep 2011 Location: North of 50° Device: Kobo Forma & Aura One & iPad Mini Retina	No - ePub format.

06-05-2016, 09:26 PM	#110
kovidgoyal creator of calibre Posts: 43,850 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	I doubt very much it has anything to do with Polish. Try sending the books without polishing and you will likely see the same behavior. An EPUB to EPUB conversion does lots of things to make EPUB files less likely to break on readers.

06-12-2016, 11:48 AM	#111
Dchiplin deb_oh_canada Posts: 34 Karma: 10 Join Date: Sep 2011 Location: North of 50° Device: Kobo Forma & Aura One & iPad Mini Retina	OK, then it appears just as Kovid states that my problem is not with Polish and that I have a more fundamental issue or I am missing something (which is quite possible!!). When I add a new book to my Calibre library, I always add or update metadata & replace cover, etc. When I send the book to my Kobo without converting, the book on the device has no jacket page. However, cover art replacements are made. Embedding does not add a jacket when book is sent to device. Modifying does add a jacket when book is sent to device (of course sending the new .ePub). Polishing seems to do something odd to the book (hence my original post). Converting sends everything I changed and I have never (yet) had a quality issue with a converted book. As well, the Kobo Utility “update metadata in device library” does not update the jacket data even though the message says it is updating. I’d be grateful for any guidance on this as I currently have to remove book from device and resend a converted copy every time I clean-up the comments or other data.

06-12-2016, 11:56 AM	#112
kovidgoyal creator of calibre Posts: 43,850 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	I'm not sure I understand you. You say that you dont want to have to delete and resend the converted book every time you make changes. But you have to do that regardless of whether you use book polishing or converting. So, since converting works well for you, just use it.

06-12-2016, 05:24 PM	#113
BetterRed null operator (he/him) Posts: 20,565 Karma: 26954694 Join Date: Mar 2012 Location: Sydney Australia Device: none	@Dchiplin - in and of itself a jacket is not metadata; it's a regular 'page' whose content is derived from the metadata, which probably explains why Embed Metadata and Kobo Utility "update metadata in device library" don't update jackets. FWIW - I use the Modify PI to refresh jackets in EPUBs. I use Modify rather than Polish because I also remove the cover and non-dc metadata elements. BR

04-23-2020, 06:39 AM	#116
kovidgoyal creator of calibre Posts: 43,850 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	calibre uses mozjpeg and optipng. Which is the same as optimge which is just a convenience wrapper.

04-24-2020, 02:55 AM	#117
dxcore35 Member Posts: 22 Karma: 10 Join Date: Mar 2018 Device: Kindle Voyage	Interesting, so it is implemented already, nice! 1) Do you know why books containing PNG takes few hours to optimize in Polish plugin or in Book editor section? The same speed is directly in Optimage module, so it looks like bug in there.... For JPGs it take just few minutes / seconds. 2) Can you put compression option with percentage in Polish plugin?

04-24-2020, 02:58 AM	#118
kovidgoyal creator of calibre Posts: 43,850 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	The way optipng work is it tried to re-compress the PNG file repeatedly with different zlib settings, this is slow. And no polish does only lossless compression, so there is no compression level. The maximum amout of lossless compression that is possible is done.

05-01-2020, 02:06 AM	#119
dxcore35 Member Posts: 22 Karma: 10 Join Date: Mar 2018 Device: Kindle Voyage	I will not say it is slow, but that it is not usable at all - hour or more to compress 20 pictures? Can you just convert them in JPG and compress it? Or ignore compression of PNG?

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05-01-2020, 03:26 AM	#120
kovidgoyal creator of calibre Posts: 43,850 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	converting to jpg involves data loss. And if you have a faster method of compressing PNG that works as well, do share.