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Old 01-11-2019, 06:09 AM   #1
PenguinCEO
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Best practice to add an image

Sometimes images (jpeg, png, etc.) in ebooks are poorly rendered by the ebook-readers based on Pearl/Carta e-ink screens,

Does it exist a best practice to add images to ebooks aimed to maximize the visual rendering of images?

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Old 01-11-2019, 01:13 PM   #2
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Since e-ink is low contrast, many images would greatly benefit from contrast stretch.
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Old 01-12-2019, 06:58 AM   #3
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Since e-ink is low contrast, many images would greatly benefit from contrast stretch.
How would that affect those of us who read on tablets and phones? I have no statistics, but I suspect that e-ink readers are a minority of devices for reading ebooks.
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Old 01-12-2019, 11:44 AM   #4
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Since e-ink is low contrast, many images would greatly benefit from contrast stretch.
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Old 01-12-2019, 12:45 PM   #5
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Old 01-12-2019, 12:48 PM   #6
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Does it exist a best practice to add images to ebooks aimed to maximize the visual rendering of images?
Use the appropriate format for the image. Generally, photos are best in JPEG, diagrams in PNG.

If you're just aiming at E-Ink screens, converting colour images into high contrast greyscale can also help. (By choosing the colour->greyscale conversion carefully you can obtain a better result than relying on the default conversion in the ebook reader.)
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Old 01-12-2019, 09:02 PM   #7
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How would that affect those of us who read on tablets and phones? I have no statistics, but I suspect that e-ink readers are a minority of devices for reading ebooks.
And I suspect you are wrong, nj. As you know, I have pretty much all the devices that are, (smile) and my preferred reader is the eInk Voyage.

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Old 01-13-2019, 10:51 AM   #8
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And I suspect you are wrong, nj. As you know, I have pretty much all the devices that are, (smile) and my preferred reader is the eInk Voyage.

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And in any case the original question referred to E-Ink screens so tablets, phones etc is a bit of topic drift.

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Old 01-13-2019, 02:46 PM   #9
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Quote:
Originally Posted by PenguinCEO View Post
Sometimes images (jpeg, png, etc.) in ebooks are poorly rendered by the ebook-readers based on Pearl/Carta e-ink screens,

Does it exist a best practice to add images to ebooks aimed to maximize the visual rendering of images?
Quote:
Originally Posted by j.p.s View Post
Since e-ink is low contrast, many images would greatly benefit from contrast stretch.
Quote:
Originally Posted by Notjohn View Post
How would that affect those of us who read on tablets and phones? I have no statistics, but I suspect that e-ink readers are a minority of devices for reading ebooks.
As others have pointed out, the OP asked about e-ink, but you make some good points. Rendering on non-e-ink displays should not be disregarded (and they probably greatly outnumber e-ink displays). I think both can be accommodated. I've thought about this from time to time for years, starting when e-ink was on the rise and seemed promising to revolutionizing reading.

I think maps, drawings, and other nominally black and white illustrations should use the full dynamic range just as text is nominally full black on a full white background. Reading software on high contrast displays already addresses the harshness that can result from this by providing options to set other background colors such as sepia. This should also be done for images. Author/publishers can set the background for non-photographic images to be transparent, yet another reason to use PNG.

It is very frustrating to have to squint at poorly scanned maps and drawing that could easily be quite legible with proper contrast. 5 to 8 inch low contrast e-ink is a challenging medium for drawings and photographs but they are capable looking pretty good and publishers should at least put some effort into it.
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Old 01-13-2019, 03:01 PM   #10
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Use the appropriate format for the image. Generally, photos are best in JPEG, diagrams in PNG.

If you're just aiming at E-Ink screens, converting colour images into high contrast greyscale can also help. (By choosing the colour->greyscale conversion carefully you can obtain a better result than relying on the default conversion in the ebook reader.)
I completely agree, but I have been surprised how good a job kindles do at rendering color images. Enough so that I prefer that images be left in color, but if a publisher actually optimizes the conversion to greyscale, I think that is great.

However I really wish publishers hadn't been producing such needlessly crap maps and drawings all these years. I am glad to see that a few books are starting to have decent images (probably because the original artwork was computer generated rather than scanned). It is very discouraging to see that many of the computer generated images have terrible JPEG artifacts.
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Old 01-13-2019, 03:12 PM   #11
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Old 01-13-2019, 03:38 PM   #12
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And in any case the original question referred to E-Ink screens so tablets, phones etc is a bit of topic drift.



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While the original post might have referred to e-ink I doubt that anyone is going to produce multiple versions of a book for differing classes of readers.

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Old 01-13-2019, 04:13 PM   #13
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While the original post might have referred to e-ink I doubt that anyone is going to produce multiple versions of a book for differing classes of readers.

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Agreed....and I certainly wouldn't "dumb down" an epub just to make it look better on eink at the expense of every other device.
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Old 01-13-2019, 04:41 PM   #14
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While the original post might have referred to e-ink I doubt that anyone is going to produce multiple versions of a book for differing classes of readers.
I'm not advocating it, but Amazon produce a mind-boggling number of different versions of books based not only on device but also software version. (I know none of them are EPUB, but still...)
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Agreed....and I certainly wouldn't "dumb down" an epub just to make it look better on eink at the expense of every other device.
Sure, but most existing e-book maps, line art, and text heavy images are downright stupid, and need to be undumbed down to look better on all devices.

How is providing proper contrast dumbing down an EPUB?
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Old 01-13-2019, 04:56 PM   #15
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I completely agree, but I have been surprised how good a job kindles do at rendering color images. Enough so that I prefer that images be left in color, but if a publisher actually optimizes the conversion to greyscale, I think that is great.
I do the same -- that is, use color whenever I have it. Of course I'm not a graphic artist, but I really can't see the difference between a color image on my Paperwhite and a grayscale-optimized image.
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