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Old 03-02-2012, 06:50 PM   #1
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nathanp began at the beginning.
Posts: 3
Karma: 10
Join Date: Mar 2012
Device: iPad
Avoid the "jagged" images in multiple e-readers

Hi guys,

This is my first post. I don't post much on here but I've used this site as a very valuable reference for my research on conversion. Now I have a real question that has been affecting quite a bit that doesn't seem to anywhere on Google.

So now I'm asking that question.

I work at an epub distributor, and am responsible for sending out books for epub conversion, as well as tweaking, fixing, or correcting epubs.

I'm looking at one major issue that kind of baffles me. Optimization for the cover display.

My dilemma is that when we convert a book, the cover will be converted at a somewhat high resolution, simpliy because a customer asked for it.

For instance, let's say we're optimizing for the full screen size of the ipad, BUT the epub will also be viewed in other devices as well.

A few things to note:

1. We only do jpg for the cover. No other formats.
2. We only do RGB. No CMYK.
3. We generally convert the cover image to about 800 high, which is about where the ipad stands.
4. We usually put in the proper CSS to restrict the cover to 100% of the viewing area. This is because readers like the Sony Reader, will cut the cover off if the actual size is too big for the viewing area unless something like { height:100% } is used.

What happens is a customer ends up viewing the cover on a different reader. Specifically one of the Sony based readers. As a result the reader will "smash" the pixels in able to resize from larger to smaller.

As a result, there is a "jagged" look to the image which seems to only appear in the more PC/Mac based readers, but looks clean on most of the reader devices.

My question there a way to avoid this at all? Different formats? Resolutions? Coding? Or are we stuck with this unless we try to optimize for each device (forcing a different epub for each distribution partner, which isn't really an option)

I would appreciate any help!
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