Covers sideloaded seperately are more nicely displayed

GeoffR · 02-22-2013, 07:45 PM

I noticed that the books I downloaded from Kobo had cover images of various aspect ratios, but were displayed nicely with a properly fitting box around the image, whereas the covers of sideloaded books (whether sent from Calibre or copied manually) were either distorted to fit a 4:3 aspect ratio or did not fit the 4:3 box around the image, leaving ugly while space.

Sending the covers seperately from the book using Calibre also distorts the cover into a 4:3 aspect ratio too.

But if I copy the cover manually from the Calibre library onto my Glo, overwriting the existing cover image ending in N3_FULL.parsed, then the cover is nicely displayed without distortion and with a properly fitting box, just as with the books downloaded from Kobo.

The pictures of the three books on the left show the difference, the first photo is with the books sent from Calibre (same result as sending covers from calibre), the second with the covers copied manually. (The two books on the right of the home screen are kepubs downloaded directly from Kobo).

robko · 02-22-2013, 08:35 PM

Interesting. I have noticed that somewhere in the more recent firmwares (not sure exactly which one) that kepub covers aren't all the same size/ratio (even accounting for the difference in size depending where they are in carousel) but are more "proper" ratio (i.e newspaper is long and thin rather than near square). Not sure what the difference in the 2 ways of adding that you're seeing but it's likely related.

davidfor · 02-22-2013, 10:48 PM

As robko said, there was a change in cover handling with FW 2.3.1. The change is how images are resized when used. With previous firmware, the aspect ratio was changed to 3:4 when the image was resized to display. But with 2.3.1, the aspect ratio is not changed when the image is displayed.

The difference that Geoff is seeing is how calibre copies covers over. When it does this, it resizes the covers to three defined sizes. But it doesn't respect the aspect ratio of the covers in the metadata. So, if you use the cover copying options for the driver, they become distorted if they don't happen to have an aspect ratio of 3:4. It is on my list of things to fix. I don't use the options, so I never see it to remind me. And not many people have noticed

jackie_w · 02-23-2013, 03:08 PM

@david,

Very few of my calibre epub cover jpgs are 3:4 ratio, but then again neither are the 'thumbnail holes' on Home screen, View Details and Library views (both list and cover). Even if the thumbnails themselves are stretched to 3:4 as they are created, once they are displayed they are restretched to perfectly fit the non-3:4 (more like 3:5 ?) thumbnail holes, i.e. they become less 'distorted' again. The only place where the 3:4 thumbnails are displayed in that ratio is when the biggest one is used as a screensaver. But, for me, the edge-to-edge 'distorted' look is a lesser evil than the horrible white sidebars (I realise this is a purely personal preference).

Whatever the calibre driver is doing right now works perfectly for me on fw2.1.5 so I hope you don't 'fix it' too much

P.S. Is there a reason why the N3_FULL.parsed thumbnail is created as 600x800 rather than 758x1024, on the KoboGlo?

GeoffR · 02-23-2013, 05:23 PM

At the moment those who want 3:4 covers without white bars can get that effect by replacing the cover in the epub with Calibre's preserve aspect ratio preference unticked, and letting the device generate the cover from the first page of the book instead of sending the covers seperately using Calibre. But it seems the only way to avoid both the white bars and the 3:4 stretching is to copy the covers manually from outside Calibre.

I have no idea how much work is involved, but I think the ideal would be if Calibre's Kobo driver had:

1. An option to either respect cover aspect ratio or use a fixed 3:4 ratio when sending covers seperately. Maybe this could be taken from Calibre's existing preserve aspect ratio epub preference setting.

2. An option to size covers to suit Mini/Touch/Glo.

davidfor · 02-23-2013, 10:57 PM

My intentions for cover support are:

- Option to not change aspect ratio when copying the covers from calibre. In fact, it wouldn't resize the cover for the largest version.

- Fix up the sizes for the Glo. The Mini should use the same sizes as the Touch, but I don't have one to check.

- Remove cover images when resending a book. That way the device will recreate them from the current version of the book. I don't plan to add an option for this as this goes along with the action of replacing the book. If any of the other cover options are selected, the covers will be replaced anyway.

I feel there is something else, but I can't think of it at the moment.

davidfor · 02-25-2013, 12:47 AM

OK, that wasn't that bad after all.

Geoff, I can't remember if I asked before, but I am going to assume that animal in your avatar is a guinea pig

And as Jackie commented... I'll send you both a PM.

jackastor · 02-26-2013, 04:05 PM

Quote:

Originally Posted by davidfor

OK, that wasn't that bad after all.

Geoff, I can't remember if I asked before, but I am going to assume that animal in your avatar is a guinea pig

And as Jackie commented... I'll send you both a PM.

Looks more like a gerbil or hamster actually

sorry for hijacking your comment

GeoffR · 03-01-2013, 10:28 PM

Thanks davidfor, the option to keep the aspect ratio for covers sent by Calibre (ver 0.9.21) is very nice. A lot of my books have covers taller and slimmer than 3:4 and look much better now, more like the paper versions.

And for those who don't like it, there are options to set the covers to 3:4 ratio, or not to send them at all (and so let the Kobo generate the cover from the first page of the book). Something for everyone :-)

02-22-2013, 07:45 PM	#1
GeoffR Wizard Posts: 3,821 Karma: 19162882 Join Date: Nov 2012 Location: Te Riu-a-Māui Device: Kobo Glo	Covers sideloaded seperately are more nicely displayed I noticed that the books I downloaded from Kobo had cover images of various aspect ratios, but were displayed nicely with a properly fitting box around the image, whereas the covers of sideloaded books (whether sent from Calibre or copied manually) were either distorted to fit a 4:3 aspect ratio or did not fit the 4:3 box around the image, leaving ugly while space. Sending the covers seperately from the book using Calibre also distorts the cover into a 4:3 aspect ratio too. But if I copy the cover manually from the Calibre library onto my Glo, overwriting the existing cover image ending in N3_FULL.parsed, then the cover is nicely displayed without distortion and with a properly fitting box, just as with the books downloaded from Kobo. The pictures of the three books on the left show the difference, the first photo is with the books sent from Calibre (same result as sending covers from calibre), the second with the covers copied manually. (The two books on the right of the home screen are kepubs downloaded directly from Kobo). Attached Thumbnails Last edited by GeoffR; 02-22-2013 at 07:52 PM. Reason: this is with firmware 2.4.0

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02-22-2013, 08:35 PM	#2
robko Wizard Posts: 2,454 Karma: 5469320 Join Date: Jul 2010 Device: Kobo	Interesting. I have noticed that somewhere in the more recent firmwares (not sure exactly which one) that kepub covers aren't all the same size/ratio (even accounting for the difference in size depending where they are in carousel) but are more "proper" ratio (i.e newspaper is long and thin rather than near square). Not sure what the difference in the 2 ways of adding that you're seeing but it's likely related.

02-22-2013, 10:48 PM	#3
davidfor Grand Sorcerer Posts: 24,907 Karma: 47303748 Join Date: Jul 2011 Location: Sydney, Australia Device: Kobo:Touch,Glo, AuraH2O, GloHD,AuraONE, ClaraHD, Libra H2O; tolinoepos	As robko said, there was a change in cover handling with FW 2.3.1. The change is how images are resized when used. With previous firmware, the aspect ratio was changed to 3:4 when the image was resized to display. But with 2.3.1, the aspect ratio is not changed when the image is displayed. The difference that Geoff is seeing is how calibre copies covers over. When it does this, it resizes the covers to three defined sizes. But it doesn't respect the aspect ratio of the covers in the metadata. So, if you use the cover copying options for the driver, they become distorted if they don't happen to have an aspect ratio of 3:4. It is on my list of things to fix. I don't use the options, so I never see it to remind me. And not many people have noticed

02-23-2013, 03:08 PM	#4
jackie_w Grand Sorcerer Posts: 6,206 Karma: 16228558 Join Date: Sep 2009 Location: UK Device: Kobo: KA1, ClaraHD, Forma, Libra2, Clara2E. PocketBook: TouchHD3	@david, Very few of my calibre epub cover jpgs are 3:4 ratio, but then again neither are the 'thumbnail holes' on Home screen, View Details and Library views (both list and cover). Even if the thumbnails themselves are stretched to 3:4 as they are created, once they are displayed they are restretched to perfectly fit the non-3:4 (more like 3:5 ?) thumbnail holes, i.e. they become less 'distorted' again. The only place where the 3:4 thumbnails are displayed in that ratio is when the biggest one is used as a screensaver. But, for me, the edge-to-edge 'distorted' look is a lesser evil than the horrible white sidebars (I realise this is a purely personal preference). Whatever the calibre driver is doing right now works perfectly for me on fw2.1.5 so I hope you don't 'fix it' too much P.S. Is there a reason why the N3_FULL.parsed thumbnail is created as 600x800 rather than 758x1024, on the KoboGlo?

02-23-2013, 05:23 PM	#5
GeoffR Wizard Posts: 3,821 Karma: 19162882 Join Date: Nov 2012 Location: Te Riu-a-Māui Device: Kobo Glo	At the moment those who want 3:4 covers without white bars can get that effect by replacing the cover in the epub with Calibre's preserve aspect ratio preference unticked, and letting the device generate the cover from the first page of the book instead of sending the covers seperately using Calibre. But it seems the only way to avoid both the white bars and the 3:4 stretching is to copy the covers manually from outside Calibre. I have no idea how much work is involved, but I think the ideal would be if Calibre's Kobo driver had: 1. An option to either respect cover aspect ratio or use a fixed 3:4 ratio when sending covers seperately. Maybe this could be taken from Calibre's existing preserve aspect ratio epub preference setting. 2. An option to size covers to suit Mini/Touch/Glo.

02-23-2013, 10:57 PM	#6
davidfor Grand Sorcerer Posts: 24,907 Karma: 47303748 Join Date: Jul 2011 Location: Sydney, Australia Device: Kobo:Touch,Glo, AuraH2O, GloHD,AuraONE, ClaraHD, Libra H2O; tolinoepos	My intentions for cover support are: - Option to not change aspect ratio when copying the covers from calibre. In fact, it wouldn't resize the cover for the largest version. - Fix up the sizes for the Glo. The Mini should use the same sizes as the Touch, but I don't have one to check. - Remove cover images when resending a book. That way the device will recreate them from the current version of the book. I don't plan to add an option for this as this goes along with the action of replacing the book. If any of the other cover options are selected, the covers will be replaced anyway. I feel there is something else, but I can't think of it at the moment.

02-25-2013, 12:47 AM	#7
davidfor Grand Sorcerer Posts: 24,907 Karma: 47303748 Join Date: Jul 2011 Location: Sydney, Australia Device: Kobo:Touch,Glo, AuraH2O, GloHD,AuraONE, ClaraHD, Libra H2O; tolinoepos	OK, that wasn't that bad after all. Geoff, I can't remember if I asked before, but I am going to assume that animal in your avatar is a guinea pig And as Jackie commented... I'll send you both a PM.

03-01-2013, 10:28 PM	#9
GeoffR Wizard Posts: 3,821 Karma: 19162882 Join Date: Nov 2012 Location: Te Riu-a-Māui Device: Kobo Glo	Thanks davidfor, the option to keep the aspect ratio for covers sent by Calibre (ver 0.9.21) is very nice. A lot of my books have covers taller and slimmer than 3:4 and look much better now, more like the paper versions. And for those who don't like it, there are options to set the covers to 3:4 ratio, or not to send them at all (and so let the Kobo generate the cover from the first page of the book). Something for everyone :-)

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