Best method for showing high res photos and additionally captions?

[FunkeXMix]

Hi all!

I am trying to piece together the best method for showing high resolution photo book type images in a reflowable kf8/ePub and I would appreciate your help (not fixed layout).

You are more then welcome to correct me, I intend this thread to become a source for this type of info.

Solution one (avoids resizing artifacts).

Kindle:

Save images at fixed size 800x600 4:3 ratio for Kindle. Should work on most Kindle screens and I assume that on Kindle Fire HD it will cover less of screen estate then you would want but you can still double tap to view full screen (right? Does ppi have any effect here?)

iBooks:

Save images at 1024x768, the oldes iPads resolution. Will iPad retina upscale, or double tap upscale?

Captions:

All I know is Elisabeth Castros method

<div class="illustration">
 <img src="images/Author.png" 
 alt="alt text"/> 
 <p>caption</p>
 </div>


 div.illustration {
 margin: 0 0 0 0.5em; padding: 0;
 border: 1px solid black;
 width: 50%; 
 float: right; 
 }
 div.illustration img {
 border: 0; margin: 0; padding: 0;
 width: 100%;
 display: inline;
 }
 div.illustration p {
 margin: 0; padding: 0;
 text-align: center;
 text-indent: 0;
 font-size: smaller;
 } 

/* With thanks to Elizabeth Castro */ 
 div.illustration+p {text-indent: 0;} /* No indent for 1st para after an illustration */

When it comes to best methods that resize images I am a bit clueless, anyone got an idea?

[dgatwood]

I would save images at the highest resolution you think your content will be viewed at. In your case, retina resolution. You can always scale down to a lower resolution, but you can never get back what isn't there. Even better, read this:

http://developer.apple.com/library/s...aDisplays.html

and use media queries to deliver different content to different devices. iBooks and most other modern eBook readers should handle media queries. Be sure to put the media queries in a separate CSS file, because Adobe Digital Editions ignores the entire file if they are present. Use this to your advantage.

BTW, if you're seeing obvious scaling artifacts, that might indicate that you aren't dealing with true photographic content, and you should consider a vector-based format like SVG instead.

[FunkeXMix]

Hey thanks for the info, but I do not think the media queries method will work with eBooks because the file size will be to big if I need to have two copies of the same image in different resolutions.

[dgatwood]

Originally Posted by FunkeXMix

Hey thanks for the info, but I do not think the media queries method will work with eBooks because the file size will be to big if I need to have two copies of the same image in different resolutions.

Probably true. It just depends on how badly the artifacts on certain readers annoy you.

On the other hand, now that I think about it, you should probably start with a different EPUB doc for Kindle anyway, because if the file sizes are too big, kindlegen recompresses the images with a lower quality setting. So regrettably, the answer on Kindle is probably "ship the low-res version".

[FunkeXMix]

I really dislike Kindles file size limit for reflowable eBooks. Makes no sense. Just 127kb. Way to go Amazon, especially since you released your Kindle HD.

[JSWolf]

Originally Posted by FunkeXMix

I really dislike Kindles file size limit for reflowable eBooks. Makes no sense. Just 127kb. Way to go Amazon, especially since you released your Kindle HD.

Isn't that limitation for Mobi and not KF8?

[dgatwood]

Originally Posted by JSWolf

Isn't that limitation for Mobi and not KF8?

Sort of. The KF8 slice gets scaled down (or for fixed-layout or comic books, recompressed at a lower quality setting) if the image is larger than 256KB.

However, since it's the same tool producing both slices at once, if you want to avoid kindlegen scaling your content, you presumably would have to either use images that are below the smaller limit or include two copies of your image and use @media rules to use the larger one for the KF8 slice. I have no idea if kindlegen is smart enough to exclude the redundant images or not.

That said, this is all just plain silly. Even 256 KB is absurdly small. In my EPUB version, I'm planning to ship the cover image at just a bit higher resolution than an iPad retina display. At 2040x2640 (JPEG high quality), the smallest of my three covers is double the KF8 limit, and the largest is almost four times the KF8 limit.

The specified size, 256 KB, isn't really even big enough for a full quality JPEG image at Kindle Fire HD resolution, much less iPad retina resolution. Of course, since Amazon doesn't support reflowing KF8 on iPad, iPad users get the 128 KB version. Compared with the 1 MB image, I can actually see the quality difference very easily in certain parts of the image even on a non-retina iPad Mini. I'd expect the difference to be pretty obvious on a full-size, retina-display iPad.

I'll start taking Amazon's KF8 format seriously when they crank that limit up to at least a megabyte, and ideally, two. Until then, my books in KF8 format will always be substandard compared with the EPUB versions, and sadly, there's not a thing I can do about it.

[Turtle91]

From what I understand Kindle's "free" book download (whispersync??) isn't free! {gasp|shock} They charge the authors per MB for people to download. After that fee is taken out then they split the remaining "profit" with the author.

So, they can certainly up the maximum image size - but it would directly decrease authors profits...end result...book prices would go up.

Based on Amazon's business model, I don't see that happening.

It would be nice to give the customer the choice though...hi-res = $1 more or no charge for internet download or something.

[Jellby]

Originally Posted by Turtle91

It would be nice to give the customer the choice though...hi-res = $1 more or no charge for internet download or something.

"Choice" is incompatible with Amazon's (and others') business model.

But why are we talking about Amazon in an ePub forum?

[mzmm]

Originally Posted by Turtle91

From what I understand Kindle's "free" book download (whispersync??) isn't free! {gasp|shock} They charge the authors per MB for people to download

i believe the download fee is only incurred on ebooks above 10Mb, so an author could get a few good size images in there without affecting sales/profits.