Stretch the cover to fit the screen?

[davidfor]

Originally Posted by jackie_w

Just a little personal anecdote ... I'm also in the 'hate filler bars' camp, especially white fillers with a dark cover. However I can't argue with the fact that stretch-to-fit occasionally looks grotesque, particularly on a cover containing a large human face.

So 18 months ago I decided to experiment with preserving the aspect ratio but doctoring the filler bars to be a better colour match for each particular cover. I thought this might be a good compromise. There are many ways to do this so I picked 3 different methods and hacked my copy of KoboTouchExtended to create the screensaver-with-designer-fillers on the fly during calibre send-to-device on 3 different Kobo models.

To cut a long story short, 18 months on I still can't decide which is the 'best' method because for some covers the fillers merge beautifully with the main cover and others don't - whichever method you pick.

Somehow I'm not surprised to hear that. I think I'd be the same. Personally, I stick with the keeping the aspect ratio and the side bands as I am much more disturbed by round things on the covers not actually being round.

One thing I did discover by accident is that screensaver appearance on an H2O or KA1 is far superior to that on a GloHD or ClaraHD. The latter two models have far more 'grayscale banding' than the former two models which have very smooth grayscale, the KA1 being the smoothest.

I would have said that since the firmware changes early last year, they were the same. But, I probably haven't been reading the same sideloaded books on multiple devices to compare. I haven't noticed any differences with purchased books as they sync. I can't see any problems on the Glo HD for the book I'm reading, but I don't have any other devices with me to compare.

[jackie_w]

Originally Posted by davidfor

I would have said that since the firmware changes early last year, they were the same. But, I probably haven't been reading the same sideloaded books on multiple devices to compare. I haven't noticed any differences with purchased books as they sync. I can't see any problems on the Glo HD for the book I'm reading, but I don't have any other devices with me to compare.

I seem to remember we had a short PM chat about this at the time I was experimenting. My observation is that whatever changes Kobo have made to image processing in the last 18 months, it has not cured the 'banding' on a GloHD screensaver.

I've attached a test epub you can play with if you want. It contains a cover full of smooth colour graduations.

The screensaver (sent as B&W, keep aspect ratio by calibre) on a GloHD is full of banding. The same book has a very smooth screensaver on a KA1. On an H2O it's not quite as smooth as the KA1 but it's still very good. The ClaraHD is very slightly better than the GloHD but still full of banding.

I transferred them all as kepub. When viewing the cover as page 1 of the kepub, rather than as a screensaver, the GloHD is much smoother, but still not as good as the KA1. The ClaraHD is smoother than the GloHD but not as good as the KA1.

[ZodWallop]

Originally Posted by jackie_w

Just a little personal anecdote ... I'm also in the 'hate filler bars' camp, especially white fillers with a dark cover. However I can't argue with the fact that stretch-to-fit occasionally looks grotesque, particularly on a cover containing a large human face.

Are you saying this beautiful cover might look weird if it was stretched?

[jackie_w]

Originally Posted by ZodWallop

Are you saying this beautiful cover might look weird if it was stretched?

Only in a hit-on-the-head-with-a-sledgehammer kind of way.

I'm not much liking the look of him un-stretched to be honest I'd need to find a different cover to avoid nightmares.

[ZodWallop]

Originally Posted by jackie_w

Only in a hit-on-the-head-with-a-sledgehammer kind of way.

I'm not much liking the look of him un-stretched to be honest I'd need to find a different cover to avoid nightmares.

Yeah, it's a good book, but that creepy cover stayed with me for years (which I guess makes it an effective cover).

[davidfor]

Originally Posted by jackie_w

I seem to remember we had a short PM chat about this at the time I was experimenting.

It rings a bell now that you mention it.

My observation is that whatever changes Kobo have made to image processing in the last 18 months, it has not cured the 'banding' on a GloHD screensaver.

I've attached a test epub you can play with if you want. It contains a cover full of smooth colour graduations.

The screensaver (sent as B&W, keep aspect ratio by calibre) on a GloHD is full of banding. The same book has a very smooth screensaver on a KA1. On an H2O it's not quite as smooth as the KA1 but it's still very good. The ClaraHD is very slightly better than the GloHD but still full of banding.

I transferred them all as kepub. When viewing the cover as page 1 of the kepub, rather than as a screensaver, the GloHD is much smoother, but still not as good as the KA1. The ClaraHD is smoother than the GloHD but not as good as the KA1.

I've done some experimenting, and I have to say the Glo HD is really bad. But, letting the device generate the cover image is fine. The device generated images are a lot larger than the calibre images. I'm sure this was OK at one point, but I don't usually send the covers. I'll have to experiment some more.

[Rand Brittain]

Lately I've been finding that even with "keep cover aspect ratio" unchecked, Calibre still isn't stretching the book covers to take up the whole screen. There's white space left on the top and bottom. Does anybody have an idea why?

[ZodWallop]

Originally Posted by Rand Brittain

Lately I've been finding that even with "keep cover aspect ratio" unchecked, Calibre still isn't stretching the book covers to take up the whole screen.

That was my initial issue. Follow posts 2 & 3 to resolve it.

[jackie_w]

Originally Posted by davidfor

But, letting the device generate the cover image is fine.

That doesn't seem to work for me on either the GloHD or the ClaraHD.

Originally Posted by davidfor

The device generated images are a lot larger than the calibre images. I'm sure this was OK at one point, but I don't usually send the covers.

The device-generated images will be in colour won't they? Might that be why they are bigger?

Originally Posted by davidfor

I'll have to experiment some more.

I'd be interested in anything you discover but I don't recall anyone else ever raising this issue, so I have to assume most people don't really care.

Just FYI, another observation on the ClaraHD, but not the GloHD, is that tapping on the page 1 kepub cover, which is originally fairly smooth, displays bad banding. Page forward/backward brings back the smoother image again. It's not a big deal - just odd.

[tourneur]

I've been out of the loop, so apologies if this has been asked before. But Kobo touch extended has been removed from my plugins, and cover images of newly added books are not being stretched anymore on the sleep screen. Is there a new solution for this? Thanks a lot.

UPDATE: nevermind, I see that I have to go into the KoboTouch driver settings now. My post can be removed mods.