Best solution for faster epub file created in InDesign for iPad

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@dw62059930  schrieb:

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The epub file is a largely illustrated comic with drawings produced in Illustrator and text applied in InDesign

 

1. For the images on each page is it best to Place the Illustrator vector files on each page (this would be my default), copy and paste the vectors from Illustrator into InDesign (so they are embed and not linked) or save Illustrator vector pages as a rasterised file such as jpeg and Place the linked jpeg?

EPUBs dont use vector files, maybe SVG is possible. JPG is not good for Illu-drawings. Use PNG. Make an object style. Add replacement text for impaired people in a meta data field and use that field in the object style. Meta information can be edited in Bridge.

 

2. Similar to above but I have a few instances where I have used InDesign animation on text and a logo that fade/slide in, and also a series of paw prints that appear across the page (to simulate walking). Should I have the animated objects as placed illustrator vectors, vectors pasted in, or vectors converted to tranparent pngs and placed?

Avoid animiations. An EPUB is not a film.

 

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Always export at 72ppi when you are working at the correct pixel size. So, if working with a iPad 2048x1536 document, export at 72 ppi. Anything over that value is waste of resources and your book will take a performance hit, as well as (in the worst case) be 3-4 times larger in file size.

[1] It depends. SVG is slow to render and animate compared to bitmap files, and depending on the complexity of the vector illustrations not necessarily smaller in terms of file size. Complex SVG files animated with javascript are a performance bottleneck - but test both versions: one with svg and one using PNG/jpg. 

In any case, my workflow is to NEVER depend on InDesign to rasterize graphics. I always use the "Use existing image for graphic objects" option in the Object Export options (epub and html tab) to ensure InDesign leaves my optimized assets well alone. InDesign is absolutely terrible at PNG image optimization.

Comic graphics generally (depending on the art style) may not require that many colours. I optimize mine with Color Quantizer http://x128.ho.ua/color-quantizer.html .

And check your final epub file for any empty PNG files. InDesign will generate those based on empty frames in your pages. These are saved as full-sized transparent PNG files, and must either be removed, or scaled down to ~64px versions. Realize that not doing this will cause these useless PNG files to gobble up video memory on a device like there is no tomorrow, and bog down performance again.

Also realize that if no tranparency is required, JPG may drastically reduce the file size of the epub. Backgrounds, for example, should be placed as JPG (unless these are simple lineart, which compresses better in PNG - but again, turn off that transparency for smaller PNG file sizes!)

PS did you know animated PNG files are supported in modern epub readers? For smaller animations which require full transparency very useful. They will not work in InDesign and must be placed via the method I mentioned above. But they do play on the Apple readers and Thorium on Windows. And in a browser.

PPS If working with SVG files: use a SVG optimizer to crunch file sizes. You can find several via Google. Then import again via above mentioned method.

It might be worth you having a look at CircularFLO, a useful facility for creating FXL ePubs from InDesign (it's Mac only): 

https://www.circularsoftware.com/apps/circularflo