Epubs and old eink reader

[rube]

Has anyone else had problems loading epubs on an old eink reader? I have an old Bebook, I love it coz the battery, even after all this time, still stays good for at least a week, but about half of the books I buy (with DRM or without) won't open on it. Is there something funny happening with newer formatting that stops them being compatible with older ereaders? (and I have the last available update for the Bebook)

Thanks for any thoughts

[PeterT]

Maybe size of the files inside the ePubs related?

[rube]

I thought of that Peter, but it's smaller epubs too. There's not an obvious pattern so I'm left wondering if there's something to do with recent formatting

[PeterT]

ePub3 vs ePub2 maybe?

[rube]

I wonder! Worth checking out. There's a lot to be said for backwards compatibility... I love my Bebook!

[theducks]

260K max for a single HTML file in the EPUB. Did you chang the Calibre default?

Bet the modern, insane , HiRes images are choking it. (My old Astak was similar HW) I use 450x300 for my images except maps, which I try and keep near full screen (aspect maintained)

[JSWolf]

Originally Posted by rube

Has anyone else had problems loading epubs on an old eink reader? I have an old Bebook, I love it coz the battery, even after all this time, still stays good for at least a week, but about half of the books I buy (with DRM or without) won't open on it. Is there something funny happening with newer formatting that stops them being compatible with older ereaders? (and I have the last available update for the Bebook)

Thanks for any thoughts

Which Reader is this?

Because it's an older Reader, the problem is most likely the graphics. Most eBooks these days include hi-res covers, sometimes a hi-res title page image, and sometimes a hi-res map. Older Readers may not be able to handle such images. They can be very slow, lock up, or reboot. I've seen the slowdown with a Sony T1. It didn't lock or reboot, but it was very slow to display these hi-res images. I don't know what would have happened has these images been included with the actual text of the eBook given the slow processor and limited system ram.

[JSWolf]

Originally Posted by theducks

260K max for a single HTML file in the EPUB. Did you chang the Calibre default?

Bet the modern, insane , HiRes images are choking it. (My old Astak was similar HW) I use 450x300 for my images except maps, which I try and keep near full screen (aspect maintained)

Yes, it is the hi-res images choking this Reader. But if you do use 450x300 for a 300DPI Reader, thes i mages can become (sometimes) too small to be of any use. The solution is that if you are going to read an ePub with hi-res graphics (on an old Reader) is to drop the graphics resolution to 800x600 (keeping the correct aspect ratio) for that Reader.

[rube]

the ducks and jswolf, yes i'm aware of the image size problems and reducing the size of the cover and title page images works sometimes but not always. I'll look at the size of the html files too, ty!
Why do they need images that big? Really?

[j.p.s]

Originally Posted by rube

the ducks and jswolf, yes i'm aware of the image size problems and reducing the size of the cover and title page images works sometimes but not always. I'll look at the size of the html files too, ty!
Why do they need images that big? Really?

They don't, but common pixel density has grown from 167dpi to 300dpi, common screen size from 5 or 6 inches to 7 or 8 inches, and gray levels from 2 to 16. Also many devices can zoom images and make use of images larger than fit on a screen.

Ebooks are also read on phones and tablets, which can make good use of even larger images.

Devices were pretty primitive 10 years ago and in some senses they still are. So file and image files will be growing out of necessity for a while yet. Someday it might be gratuitous and uncalled for, but we aren't there yet.

[DNSB]

Originally Posted by rube

Why do they need images that big? Really?

My Forma has a 1440x1920 screen. So yes, an image close to that size is best for a full screen image. The only other images that I like in a large size are things like maps where a couple of times, I've downloaded high resolution images from the author so I can zoom in on the map without seeing pixelation. Everyone needs a 12958x10500 pixel map (about 52MB)

[JSWolf]

Originally Posted by rube

the ducks and jswolf, yes i'm aware of the image size problems and reducing the size of the cover and title page images works sometimes but not always. I'll look at the size of the html files too, ty!
Why do they need images that big? Really?

Have you ever tried to read text in a small image on a hi-res screen with a resolution of 1430 x 1080 (and newer Readers have a higher resolution at 1072 x 1448 for a 6" screen and larger screens have an even higher resolution.

Yes, we do need high resolution images in order to have full screen images that are not pixilated and/or fuzzy.

Older Readers with 800x600 resolution screen have difficulties handling these hi-res images. That's what causes problems with these old Readers.

[rube]

Some of the images I've resized I've found to be big enough to display on a large screen tv! No one reads ebooks on a large screen tv. I wonder what the publishers would say if they knew how many of their books get opened up and the images resized

[JSWolf]

Originally Posted by rube

Some of the images I've resized I've found to be big enough to display on a large screen tv! No one reads ebooks on a large screen tv. I wonder what the publishers would say if they knew how many of their books get opened up and the images resized

eInk works completely differently then LCD. A small image on a hi-res LCD screen can look OK. But a small image on a hi-res eInk screen may not look OK. You cannot take a low-res image (say a map) and make it full screen on a hi-res eInk screen without the image being fuzzy.

One of the problems was because of Mobipocket. Before eInk, Mobipocket had a limit on the size of images. I think it was a limit on the size of the images. So when Mobipocket eBooks were converted to other formats, the images were overly compressed and too small. A lot of the original devices used to read Mobipocket had small low-res screen such as a Blackberry. With eInk, the screen started off at 6" with a resolution of 800x600 and mostly stayed that way. There were some larger screens with a higher resolution such as the iRex and the Kindle DX. There were some that used 1024x758 resolution screens. But eInk did not get truly hi-res until 300dpi screen became the screens for most Readers. The older Readers didn't have hi-res, didn't have much system memory, and they didn't have all that fast a processor. Plus, eBooks back then has low-res images.

Now we have 300dpi Readers and hi-res images at least for the cover and title page image. These older Readers were never designed to handle such large graphics. They slowed down, froze, or rebooted. It has almost nothing to do with the size of the HTML file. It has to do with the size if the graphics.

[Quoth]

Actually the original devices for Mobipocket were PDAs, 160 x 160 pixels. By the time Palm did a 320 x 320 PDA there were already also "smart phones" using Symbian and 320 x 240, with Mobipocket.
My Palm Z22 does do colour, but none of the supported eReader applications seem to have images in them. No cover view either back then.
Apple has caused the cover image to become enormous by insisting on image sizes to suit "Retina" resolution iPads.