Kobo Touch Displays Some SVG Images as Black Rectangles

MikeWV · 07-02-2014, 03:37 PM

After updating my Kobo Touch to 3.3.0, a third of my SVG tables display as pure black rectangles. I don't have this problem with any of my SVG charts. Both tables and charts are SVG images within <img> tags. And I didn't have this problem until I updated my firmware.

I can't find anything common to the tables that are displaying as black rectangles other than things that are also present in tables that display correctly. Due to the Touch's choice of default san-serif font, I have some text extending beyond the right boundary of many of the table images, but that's happening in some of tables that are displaying, too. I tried extending the boundary of a couple of the images but it had no effect; I still get a black rectangle.

All of the tables display properly in Kobo PC, Kobo Android and ADE, so if has something to do with the files, then it is something that Kobo's firmware version 3.3.0 doesn't like.

Needless to say, as I've written two books that I plan to offer for sale, the fact that I can't read them on my Touch isn't the problem. The problem is getting all of my images to display correctly on all or most devices.

This is happening with .kepup.epub. If I change the extension to .epub, all of the tables display, although their appearance leaves a lot to be desired and, of course, the Y-axis titles of the charts are scrambled.

Any suggestions as to what I should look for in the problem files would be appreciated.

PeterT · 07-02-2014, 03:53 PM

I'm a bit confused... KEpub format and the engine it uses on both the PC and Kobo devices is not supported for material other than that obtained from the Kobo shop, and I presume it's safe to say either created via Kobo Writing Life or converted by Kobo when material is supplied via a publisher to them.

Expecting either an ePub converted by the calibre plugins to kEpub format, or one that has been simply renamed to work fully is a bit of a long shot.

MikeWV · 07-02-2014, 04:09 PM

I guess I'd better reread their documentation or read more of it. I read the part about testing and all they said was to convert .epubs to .kepub.epubs by changing the format then test on as many platforms as possible.

How do they expect authors to test their work if there is no means to make a conversion that is equivalent to what they do before delivering to customers?

JSWolf · 07-02-2014, 04:59 PM

Quote:

Originally Posted by MikeWV

I guess I'd better reread their documentation or read more of it. I read the part about testing and all they said was to convert .epubs to .kepub.epubs by changing the format then test on as many platforms as possible.

How do they expect authors to test their work if there is no means to make a conversion that is equivalent to what they do before delivering to customers?

But does it work as a regular ePub with your Kobo?

PeterT · 07-02-2014, 05:16 PM

I think that if you work through the official Kobo Writing route that you will get support via them for your content creation.

MikeWV · 07-02-2014, 05:58 PM

Yes, as a plain .epub the tables display but the default font messes them up. On the bright side, the embedded fonts are recognized, but then I have a problem with the Y-axis titles of my charts. The Kobo .epub software reverses the characters and mangles the spacing of any rotated text, which is a know issue and apparently has been for some time.

davidfor · 07-02-2014, 10:24 PM

Any chance of seeing an sample? Maybe an epub that has just a working and a non-working version. I'd like to see what happens on the firmware version I am running on my Kobos.

MikeWV · 07-03-2014, 12:12 PM

As requested, I've attached a sample of my book, Chapter 4 and Appendix III, as a plain ePub. Just change the extension to .kepub.epub to view it as a KePub.

What I'm seeing on my Kobo Touch (3.3.0) as a KePub are black rectangles for the following images: Table 4-1, Table A3-2 and a block of formulas one paragraph below A3-2. You can also see that the firmware is ignoring my embedded fonts. When viewed on my Touch as a plain ePub (.epub), I have neither of these problems but the default fonts in the images are obviously inappropriate and rotated text (like Y-axis titles) is scrambled.

Kobo apparently has a problem with image dimensions, too. Table A3-1, for example, is set at 80% but is displayed at much less than that on my Touch. SVG image quality is also an issue, it obviously leaves a lot to be desired with Kobo PC and on the Kobo Touch, but it looks good in Kobo Android for some reason. Everything looks good and as it should in ADE, it even recognizes my embedded fonts in the last three Appendix III images.

DomesticExtremis · 07-03-2014, 02:42 PM

You might find you get better help posting in the Kobo forums as these problems seem to be Kobo specific.

MikeWV · 07-03-2014, 03:14 PM

I may give the Kobo forums a try. I thought the Kobo forums were mainly for reader issues rather than technical issues experienced by authors, but I never took a look to verify that.

I hope it's Kobo specific. I haven't tried B&N or Apple yet. Amazon will be my last stop. I expect I'll have all sorts of problems satisfying them. I figured if I could get everything working on Kobo, then it should probably work on B&N and hopefully Apple, too, without too much addition modification.

GeoffR · 07-09-2014, 01:23 PM

I tried it on my Glo with firmware 3.4.1:

With the epub reader the .svg images display okay, but the embedded fonts don't work. With the kepub reader I get the same black rectangles that you describe, and also the embedded fonts don't work.

The problem with the embedded fonts is simply that there is no reference to them in the stylesheet: there are no @font-face declarations.

Sorry I don't know what the problem with the .svg images is, but then I don't normally use sideloaded kepubs. I've never seen the problem in Kobo-made kepubs.

Edit: The embedded fonts worked in the .svg tables as you described, I was thinking you meant the main text to use these fonts.

tshering · 07-09-2014, 03:11 PM

All images show nice in kepub.epub on FW 2.6.1. With FW 3.4.1 I see the black rectangles.

MikeWV · 07-09-2014, 03:27 PM

I had the @font-face declarations in the stylesheet but it didn't seem to make any difference. So I assumed that the only reference necessary was the @font-face declaration in the SVG defs and I therefore removed them from the stylesheet. I'll add them back and try it again.

It looks like the black rectangles are going to remain a problem until Kobo fixes their more recent firmware. I didn't have the problem with 2.x and neither did tshering but all three of us have the problem under 3.x. Being that it's only some of the images that are 100% black, it seems like there must be something causing it, but I can't find anything common to all of the black images that is not also present in some of the images that display properly. There are 55 images in that one book and a third of them are all black, so I have plenty of images to compare. It's really aggravating. It doesn't happen in any of the various PC and Android apps I've tried.

Thanks for your input.

tshering · 07-09-2014, 03:33 PM

Did you try to exchange the location of showing and non-showing images just as an experiment?

MikeWV · 07-10-2014, 03:18 PM

GeoffR,

As PeterT noted, I may need to convert the epub to kepub using Kobo's conversion rather than just changing the extension. However, it seems like there should be a means for authors to test their work before submitting it to Kobo. I'm going to look into that now. However, if I stack my Y-axis titles instead of rotating them and embed fonts in all of my SVGs, plain old epub will work. If Kobo won't let me sell on their site without converting to kepub, then I'll have to take a pass on Kobo until they fix their firmware.

tshering,

I tried swapping the locations of two pairs of working and blacked out images and got mixed results. In one case, I ended up with two blacked out images instead of one, and in the other case, the image that was originally blacked out was still blacked out in the new location and the good image was still displayed properly when moved to the original location of the blacked out image.

07-02-2014, 03:37 PM	#1
MikeWV Connoisseur Posts: 54 Karma: 10 Join Date: Nov 2013 Device: Kobo Touch	Kobo Touch Displays Some SVG Images as Black Rectangles After updating my Kobo Touch to 3.3.0, a third of my SVG tables display as pure black rectangles. I don't have this problem with any of my SVG charts. Both tables and charts are SVG images within <img> tags. And I didn't have this problem until I updated my firmware. I can't find anything common to the tables that are displaying as black rectangles other than things that are also present in tables that display correctly. Due to the Touch's choice of default san-serif font, I have some text extending beyond the right boundary of many of the table images, but that's happening in some of tables that are displaying, too. I tried extending the boundary of a couple of the images but it had no effect; I still get a black rectangle. All of the tables display properly in Kobo PC, Kobo Android and ADE, so if has something to do with the files, then it is something that Kobo's firmware version 3.3.0 doesn't like. Needless to say, as I've written two books that I plan to offer for sale, the fact that I can't read them on my Touch isn't the problem. The problem is getting all of my images to display correctly on all or most devices. This is happening with .kepup.epub. If I change the extension to .epub, all of the tables display, although their appearance leaves a lot to be desired and, of course, the Y-axis titles of the charts are scrambled. Any suggestions as to what I should look for in the problem files would be appreciated.

07-02-2014, 05:58 PM	#6
MikeWV Connoisseur Posts: 54 Karma: 10 Join Date: Nov 2013 Device: Kobo Touch	Yes, as a plain .epub the tables display but the default font messes them up. On the bright side, the embedded fonts are recognized, but then I have a problem with the Y-axis titles of my charts. The Kobo .epub software reverses the characters and mangles the spacing of any rotated text, which is a know issue and apparently has been for some time. Last edited by MikeWV; 07-02-2014 at 06:01 PM.

07-09-2014, 01:23 PM	#11
GeoffR Wizard Posts: 3,821 Karma: 19162882 Join Date: Nov 2012 Location: Te Riu-a-Māui Device: Kobo Glo	I tried it on my Glo with firmware 3.4.1: With the epub reader the .svg images display okay, but the embedded fonts don't work. With the kepub reader I get the same black rectangles that you describe, and also the embedded fonts don't work. The problem with the embedded fonts is simply that there is no reference to them in the stylesheet: there are no @font-face declarations. Sorry I don't know what the problem with the .svg images is, but then I don't normally use sideloaded kepubs. I've never seen the problem in Kobo-made kepubs. Edit: The embedded fonts worked in the .svg tables as you described, I was thinking you meant the main text to use these fonts. Last edited by GeoffR; 07-09-2014 at 04:30 PM. Reason: embedded fonts work in epub reader

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07-02-2014, 03:53 PM	#2
PeterT Grand Sorcerer Posts: 13,511 Karma: 78910202 Join Date: Nov 2007 Location: Toronto Device: Libra H2O, Libra Colour	I'm a bit confused... KEpub format and the engine it uses on both the PC and Kobo devices is not supported for material other than that obtained from the Kobo shop, and I presume it's safe to say either created via Kobo Writing Life or converted by Kobo when material is supplied via a publisher to them. Expecting either an ePub converted by the calibre plugins to kEpub format, or one that has been simply renamed to work fully is a bit of a long shot.

07-02-2014, 04:09 PM	#3
MikeWV Connoisseur Posts: 54 Karma: 10 Join Date: Nov 2013 Device: Kobo Touch	I guess I'd better reread their documentation or read more of it. I read the part about testing and all they said was to convert .epubs to .kepub.epubs by changing the format then test on as many platforms as possible. How do they expect authors to test their work if there is no means to make a conversion that is equivalent to what they do before delivering to customers?

07-02-2014, 05:16 PM	#5
PeterT Grand Sorcerer Posts: 13,511 Karma: 78910202 Join Date: Nov 2007 Location: Toronto Device: Libra H2O, Libra Colour	I think that if you work through the official Kobo Writing route that you will get support via them for your content creation.

07-02-2014, 10:24 PM	#7
davidfor Grand Sorcerer Posts: 24,905 Karma: 47303824 Join Date: Jul 2011 Location: Sydney, Australia Device: Kobo:Touch,Glo, AuraH2O, GloHD,AuraONE, ClaraHD, Libra H2O; tolinoepos	Any chance of seeing an sample? Maybe an epub that has just a working and a non-working version. I'd like to see what happens on the firmware version I am running on my Kobos.

07-03-2014, 02:42 PM	#9
DomesticExtremis Addict Posts: 243 Karma: 359054 Join Date: Nov 2012 Device: default	You might find you get better help posting in the Kobo forums as these problems seem to be Kobo specific.

07-03-2014, 03:14 PM	#10
MikeWV Connoisseur Posts: 54 Karma: 10 Join Date: Nov 2013 Device: Kobo Touch	I may give the Kobo forums a try. I thought the Kobo forums were mainly for reader issues rather than technical issues experienced by authors, but I never took a look to verify that. I hope it's Kobo specific. I haven't tried B&N or Apple yet. Amazon will be my last stop. I expect I'll have all sorts of problems satisfying them. I figured if I could get everything working on Kobo, then it should probably work on B&N and hopefully Apple, too, without too much addition modification.

07-09-2014, 03:11 PM	#12
tshering Wizard Posts: 3,489 Karma: 2914715 Join Date: Jun 2012 Device: kobo touch	All images show nice in kepub.epub on FW 2.6.1. With FW 3.4.1 I see the black rectangles.

07-09-2014, 03:27 PM	#13
MikeWV Connoisseur Posts: 54 Karma: 10 Join Date: Nov 2013 Device: Kobo Touch	I had the @font-face declarations in the stylesheet but it didn't seem to make any difference. So I assumed that the only reference necessary was the @font-face declaration in the SVG defs and I therefore removed them from the stylesheet. I'll add them back and try it again. It looks like the black rectangles are going to remain a problem until Kobo fixes their more recent firmware. I didn't have the problem with 2.x and neither did tshering but all three of us have the problem under 3.x. Being that it's only some of the images that are 100% black, it seems like there must be something causing it, but I can't find anything common to all of the black images that is not also present in some of the images that display properly. There are 55 images in that one book and a third of them are all black, so I have plenty of images to compare. It's really aggravating. It doesn't happen in any of the various PC and Android apps I've tried. Thanks for your input.

07-09-2014, 03:33 PM	#14
tshering Wizard Posts: 3,489 Karma: 2914715 Join Date: Jun 2012 Device: kobo touch	Did you try to exchange the location of showing and non-showing images just as an experiment?

07-10-2014, 03:18 PM	#15
MikeWV Connoisseur Posts: 54 Karma: 10 Join Date: Nov 2013 Device: Kobo Touch	GeoffR, As PeterT noted, I may need to convert the epub to kepub using Kobo's conversion rather than just changing the extension. However, it seems like there should be a means for authors to test their work before submitting it to Kobo. I'm going to look into that now. However, if I stack my Y-axis titles instead of rotating them and embed fonts in all of my SVGs, plain old epub will work. If Kobo won't let me sell on their site without converting to kepub, then I'll have to take a pass on Kobo until they fix their firmware. tshering, I tried swapping the locations of two pairs of working and blacked out images and got mixed results. In one case, I ended up with two blacked out images instead of one, and in the other case, the image that was originally blacked out was still blacked out in the new location and the good image was still displayed properly when moved to the original location of the blacked out image.

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