KOBO CBZ support - Few questions

AcidWeb · 12-22-2013, 02:59 AM

Hello,

Recently, I began to think about supporting officially non-Kindle readers in our application. I never used Kobo device so I have come here to ask some questions and find some volunteers who could provide me some feedback.

Our Kindle Comic Converter as the name suggests was created mostly for Kindle devices but I heard that Kobo devices family is too good to ignore it any longer.

Before I provide some files to test I have some questions...

What format is better for your readers? CBZ or EPUB? I heard that zoom is working better in CBZ.
All current models (Mini, Touch, Glo, Aura and Aura HD) have this same CBZ reader?
Entire screen is available during reading CBZ files? No progress bar that you can't hide?
How exactly zoom is working in CBZ reader?
Downsampling working correctly? If image is bigger than screen e-reader resize it to show entire image by default?
And the most important question. How you convert comic/manga to read it? Do you even optimize images for e-ink screens?

Thank you. If you need to talk with me directly - find me on MobileRead IRC channel.

zztush · 12-22-2013, 04:32 AM

3. yes
4. Zoom is not bad but not good enough for reading. I enjoy zoom only occasional use.
5. yes. But I think we should optimize images before reading by converter.
6. I just make cbz filles optimize before reading. Size and ration of image files are important.

AcidWeb · 12-22-2013, 04:44 AM

OK. Thank you. You use Kobo Touch right? 600x800 screen if I remember correctly.

Can you please try this two files and share your opinion about quality?

This one is resized to 600x800 so quality of zoom should be very low.
http://pawelj.vulturis.eu/Shared/Ubunchu!-NoZoom.cbz

This one is 900x1200. So 150% zoom should look perfectly. I have no idea if you can set exactly 150% zoom on Kobo.
http://pawelj.vulturis.eu/Shared/Ubunchu!-150Zoom.cbz

Ken Maltby · 12-22-2013, 10:42 AM

The 900x1200 looks great on my AuraHD in Koreader build 713. Which is a little odd because they just switched to using FFI and image rendering is a little off what it used to be. Your .jpg are rendering great, just like they did before the change. The AuraHD is 1080x1440 so no zoom is involved.

Luck;
Ken

AcidWeb · 12-22-2013, 10:58 AM

Good to know that even smaller images look nice on Aura HD.

Here you have Aura HD version (1080x1440):
http://pawelj.vulturis.eu/Shared/Ubunchu!-KAHD.cbz

But Aura HD profile is easy one. I'm mostly interested with comparison of sharpness 600x800 vs 900x1200 (when it is not zoomed) on 600x800 screen.

Kindle downsampling blur image a little.

Ken Maltby · 12-22-2013, 11:20 AM

Tried the HD version and they look pretty much the same. I don't read Japanese so I can't tell if there is a difference in the legibility of the small complex pictographs.

Luck;
Ken

zztush · 12-23-2013, 09:15 AM

Both NoZoom and 150Zoom work perfect on my kobo touch. I can read all of the text on those manga. No need to zoom in or out to fit the size. I think the ratio is perfect for my kobo touch. Thanks sharing this sample.

AcidWeb · 12-23-2013, 09:42 AM

OK. Thank you.

I think that I have enought data to create all Kobo profiles.

AcidWeb · 12-27-2013, 08:13 AM

OK. I finished profiles. Need feedback how they look on target devices.
All except Aura HD one use images with size = 150% device resolution so zoom should still be HQ.

http://pawelj.vulturis.eu/Shared/Ubunchu!-MiniTouch.cbz
http://pawelj.vulturis.eu/Shared/Ubunchu!-Glow.cbz
http://pawelj.vulturis.eu/Shared/Ubunchu!-Aura.cbz
http://pawelj.vulturis.eu/Shared/Ubunchu!-AuraHD.cbz

harakiri · 12-31-2013, 03:43 AM

I am a prowd owner of a Kobo Aura.
I got the version for this model. It looks good. Page fills the complete screen. Text is readable.

12-22-2013, 02:59 AM	#1
AcidWeb KCC Co-Author Posts: 845 Karma: 765434 Join Date: Mar 2013 Location: Poland Device: Kindle Oasis 2	KOBO CBZ support - Comics/Manga - Few questions Hello, Recently, I began to think about supporting officially non-Kindle readers in our application. I never used Kobo device so I have come here to ask some questions and find some volunteers who could provide me some feedback. Our Kindle Comic Converter as the name suggests was created mostly for Kindle devices but I heard that Kobo devices family is too good to ignore it any longer. Before I provide some files to test I have some questions... What format is better for your readers? CBZ or EPUB? I heard that zoom is working better in CBZ. All current models (Mini, Touch, Glo, Aura and Aura HD) have this same CBZ reader? Entire screen is available during reading CBZ files? No progress bar that you can't hide? How exactly zoom is working in CBZ reader? Downsampling working correctly? If image is bigger than screen e-reader resize it to show entire image by default? And the most important question. How you convert comic/manga to read it? Do you even optimize images for e-ink screens? Thank you. If you need to talk with me directly - find me on MobileRead IRC channel. Last edited by AcidWeb; 12-22-2013 at 03:15 AM.

12-22-2013, 10:42 AM	#4
Ken Maltby Wizard Posts: 4,466 Karma: 6900052 Join Date: Dec 2009 Location: The Heart of Texas Device: Boox Note2, AuraHD, PDA,	The 900x1200 looks great on my AuraHD in Koreader build 713. Which is a little odd because they just switched to using FFI and image rendering is a little off what it used to be. Your .jpg are rendering great, just like they did before the change. The AuraHD is 1080x1440 so no zoom is involved. Luck; Ken Last edited by Ken Maltby; 12-22-2013 at 10:46 AM.

12-22-2013, 10:58 AM	#5
AcidWeb KCC Co-Author Posts: 845 Karma: 765434 Join Date: Mar 2013 Location: Poland Device: Kindle Oasis 2	Good to know that even smaller images look nice on Aura HD. Here you have Aura HD version (1080x1440): http://pawelj.vulturis.eu/Shared/Ubunchu!-KAHD.cbz But Aura HD profile is easy one. I'm mostly interested with comparison of sharpness 600x800 vs 900x1200 (when it is not zoomed) on 600x800 screen. Kindle downsampling blur image a little. Last edited by AcidWeb; 12-22-2013 at 11:11 AM.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
CBZ lag and reliability issues in Kobo Glo	abigsmurf	Kobo Reader	3	03-22-2013 06:05 AM
CBZ to MOBI cover problem on Kobo	stanlefor	Conversion	5	12-04-2012 05:59 AM
Kobo Wifi CBR/CBZ/RTF support	shouled	Kobo Reader	0	11-30-2012 11:20 AM
problem with CBR/CBZ conversion for Kobo	gweeks	Conversion	4	04-03-2011 01:00 AM
PRS-650 CBZ, CBR, ZIP or RAR file support?	Renji	Sony Reader Dev Corner	4	12-01-2010 08:43 AM

12-22-2013, 04:32 AM	#2
zztush Connoisseur Posts: 69 Karma: 5542 Join Date: Dec 2012 Location: Osaka, Japan Device: Kobo Touch, iPad, iPod and NintendoDS	3. yes 4. Zoom is not bad but not good enough for reading. I enjoy zoom only occasional use. 5. yes. But I think we should optimize images before reading by converter. 6. I just make cbz filles optimize before reading. Size and ration of image files are important.

12-22-2013, 04:44 AM	#3
AcidWeb KCC Co-Author Posts: 845 Karma: 765434 Join Date: Mar 2013 Location: Poland Device: Kindle Oasis 2	OK. Thank you. You use Kobo Touch right? 600x800 screen if I remember correctly. Can you please try this two files and share your opinion about quality? This one is resized to 600x800 so quality of zoom should be very low. http://pawelj.vulturis.eu/Shared/Ubunchu!-NoZoom.cbz This one is 900x1200. So 150% zoom should look perfectly. I have no idea if you can set exactly 150% zoom on Kobo. http://pawelj.vulturis.eu/Shared/Ubunchu!-150Zoom.cbz

12-22-2013, 11:20 AM	#6
Ken Maltby Wizard Posts: 4,466 Karma: 6900052 Join Date: Dec 2009 Location: The Heart of Texas Device: Boox Note2, AuraHD, PDA,	Tried the HD version and they look pretty much the same. I don't read Japanese so I can't tell if there is a difference in the legibility of the small complex pictographs. Luck; Ken

12-23-2013, 09:15 AM	#7
zztush Connoisseur Posts: 69 Karma: 5542 Join Date: Dec 2012 Location: Osaka, Japan Device: Kobo Touch, iPad, iPod and NintendoDS	Both NoZoom and 150Zoom work perfect on my kobo touch. I can read all of the text on those manga. No need to zoom in or out to fit the size. I think the ratio is perfect for my kobo touch. Thanks sharing this sample.

12-23-2013, 09:42 AM	#8
AcidWeb KCC Co-Author Posts: 845 Karma: 765434 Join Date: Mar 2013 Location: Poland Device: Kindle Oasis 2	OK. Thank you. I think that I have enought data to create all Kobo profiles.

12-27-2013, 08:13 AM	#9
AcidWeb KCC Co-Author Posts: 845 Karma: 765434 Join Date: Mar 2013 Location: Poland Device: Kindle Oasis 2	OK. I finished profiles. Need feedback how they look on target devices. All except Aura HD one use images with size = 150% device resolution so zoom should still be HQ. http://pawelj.vulturis.eu/Shared/Ubunchu!-MiniTouch.cbz http://pawelj.vulturis.eu/Shared/Ubunchu!-Glow.cbz http://pawelj.vulturis.eu/Shared/Ubunchu!-Aura.cbz http://pawelj.vulturis.eu/Shared/Ubunchu!-AuraHD.cbz

12-31-2013, 03:43 AM	#10
harakiri Groupie Posts: 174 Karma: 464618 Join Date: Jun 2010 Location: Germany Device: Kindle Oasis 2	I am a prowd owner of a Kobo Aura. I got the version for this model. It looks good. Page fills the complete screen. Text is readable.

Advert

Advert