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JohannesM · 01-30-2018, 05:57 AM

Hello

I have a problem with a fixed layout epub that I've tried to solve for a long time to no avail, thought maybe asking for help here would be a good idea.

I'm converting a ~600-page maths textbook to fxl epub. I have the design in Indesign, interactions work and all displays very nicely. However there's a problem when opening the epub in any tablet reader (I have an older iPad 2 and a Lenovo pad for testing). Each page takes a few seconds to load on tablets.
The epub itself is very large - around 40MB, since all the formulas and math symbols are represented as png pictures and it's quite heavy on them.

I have two main suspects - both stemming from Indesign:

For positioning exactly as seen on Indesign editor, it gives each word and image an id with which to position the element - that makes the css file about 3MB large, 93k rows. I thought I might fix that by breaking up the css so each file would get a unique css file which would have only classes and id-s used in that file. Wrote the script for that and repacked the epub with separated css files but it didn't work - the loading times were still slow.
Another suspect is that for precise positioning Indesign enlarges the resolution - it gives everything 20x larger dimensions and then uses css transform to scale it 0.05 times back again. This might be another case where the reader has to think and calculate too much before displaying the page. Maybe there's a checkbox somewhere to tell it to not scale it all? I could try writing a script that would recalculate everything to normal size but maybe that's not even an issue, since Indesign makes it automatically - I don't think it's possible that it enforces a solution which would be unreadable.

Example page: https://pastebin.com/vGqVatD5
I'm using Indesign CC2017 and Sigil. Using Indesign is mandatory for this project, since it holds the design and re-doing the 600 page maths textbook and realigning all formulas etc. in some other program is just not worth the time. Sigil was for cleanup, it actually reduced the file size

Can anyone point me to some direction - I might not have thought about everything yet which might make the reading experience slow.

01-30-2018, 05:57 AM	#1
JohannesM Junior Member Posts: 7 Karma: 100 Join Date: Jan 2018 Device: none	Indesign to fixed layout epub very slow Hello I have a problem with a fixed layout epub that I've tried to solve for a long time to no avail, thought maybe asking for help here would be a good idea. I'm converting a ~600-page maths textbook to fxl epub. I have the design in Indesign, interactions work and all displays very nicely. However there's a problem when opening the epub in any tablet reader (I have an older iPad 2 and a Lenovo pad for testing). Each page takes a few seconds to load on tablets. The epub itself is very large - around 40MB, since all the formulas and math symbols are represented as png pictures and it's quite heavy on them. I have two main suspects - both stemming from Indesign: For positioning exactly as seen on Indesign editor, it gives each word and image an id with which to position the element - that makes the css file about 3MB large, 93k rows. I thought I might fix that by breaking up the css so each file would get a unique css file which would have only classes and id-s used in that file. Wrote the script for that and repacked the epub with separated css files but it didn't work - the loading times were still slow. Another suspect is that for precise positioning Indesign enlarges the resolution - it gives everything 20x larger dimensions and then uses css transform to scale it 0.05 times back again. This might be another case where the reader has to think and calculate too much before displaying the page. Maybe there's a checkbox somewhere to tell it to not scale it all? I could try writing a script that would recalculate everything to normal size but maybe that's not even an issue, since Indesign makes it automatically - I don't think it's possible that it enforces a solution which would be unreadable. Example page: https://pastebin.com/vGqVatD5 I'm using Indesign CC2017 and Sigil. Using Indesign is mandatory for this project, since it holds the design and re-doing the 600 page maths textbook and realigning all formulas etc. in some other program is just not worth the time. Sigil was for cleanup, it actually reduced the file size Can anyone point me to some direction - I might not have thought about everything yet which might make the reading experience slow.