Cover Size for epubs etc

[jackastor]

Just wondering because someone had mentioned cover size being important. At the time I had no idea what to make of it. What is the size that should be used for covers to ensure they show up? I had assumed that the covers from amazon isbn etc were standard sizes. Prehaps this is not so. So what is the correct size to ensure your covers show clear clean and reasonable?

regards

jack

[Starson17]

Originally Posted by jackastor

So what is the correct size to ensure your covers show clear clean and reasonable?

The same as the resolution of your ereader screen. Higher res is a waste (unless you zoom) and lower is fuzzy.

[jackastor]

Originally Posted by Starson17

The same as the resolution of your ereader screen. Higher res is a waste (unless you zoom) and lower is fuzzy.

Well thats one way of saying things. but it really doenst say anything.

[speakingtohe]

AFAIK, and I could be wrong, calibre will adjust covers for your reader when it can.
In simple terms, if the cover fills the box in edit metadata it should look good in your reader.

I go generally for around 3x5 ratio (ie 318x480 or 309x475) but I am not obsessive about it.

If a bigger cover looks more appealing (~600x800) I pick that one and so far they look fine on my reader.

Helen

[LGN]

But don't forget that in the future higher resolutions might appear on ereaders and tablets

[alansplace]

Originally Posted by jackastor

Just wondering because someone had mentioned cover size being important. At the time I had no idea what to make of it. What is the size that should be used for covers to ensure they show up? I had assumed that the covers from amazon isbn etc were standard sizes. Prehaps this is not so. So what is the correct size to ensure your covers show clear clean and reasonable?

regards

jack

Originally Posted by Starson17

The same as the resolution of your ereader screen. Higher res is a waste (unless you zoom) and lower is fuzzy.

Originally Posted by jackastor

Well thats one way of saying things. but it really doenst say anything.

sure it says something. that the optimal size of your cover image is the same as your device's display size. i have a kiindle 3 with a display of 600x800 pixels. so the optimal size for a cover image for my device is 600x800 pixels.

[Snauzoo]

hmmmm... my NOOK says the screen resolution is 600x1024 and there are NO book cover images that size. My problem right now is that my covers are getting chopped off at the bottom and are fatter than they should be. Some of the css in my books has a huge amount of code related to sizing image and it is all mumbo jumbo. I used to go for the largest cover image I could get so they looked good on my iPad. I hate the idea that I have to have a nook library with the same books as the ipad's library so I can have two different cover images! Is there a way around this? And I did think what was said made sense until I realized how high res my nook color is.

[jackastor]

Originally Posted by alansplace

sure it says something. that the optimal size of your cover image is the same as your device's display size. i have a kiindle 3 with a display of 600x800 pixels. so the optimal size for a cover image for my device is 600x800 pixels.

Actually it doesnt really, but what you say does make better sense. But the problem is the covers just dont show up regardless. The show up on the initial transfer from calibre and show up as the thumbnails in the on card a display but then when you eject the reader process them and then you get blank covers.... The same books go over to stanza no problem with the covers so i dont understand why they dont show. I have tried everything from adjusting covers down to smaller... dumping the ebook and recreating it. dumping the cover and reconverting and adding the meta data again and again. So I am at a loss as to why the covers dont show. Which brings me to my question about cover sizes. And my frustration on the lack of covers. Oh sometimes i get a cover to show. but its rare and i can never duplicate it. on my Kobo Touch its that random.

thanks for the information.

And thanks for all who offered up their suggestions so far. Hopefully something will click and I will have an answer or solution. I strongly think its Calibre that is at fault. But not being a programer I cant say for sure. But I think it is.

regards

jack

[Starson17]

Originally Posted by jackastor

Well thats one way of saying things. but it really doenst say anything.

Actually, I think it's a highly useful answer that directly answered your question.

I'm totally confused as to what more you could want? You asked for: "correct size to ensure your covers show clear clean and reasonable." Calibre will adjust image resolution based on your ereader output device to provide a clear image of reasonable size. "Clear" and "reasonable" are tradeoffs and the tradeoff is based on the resolution the output Calibre produces, which depends on the ereader device. You didn't tell us what output device you've specified.

If your image has fewer pixels than the device will display, it's not "clear." If you have more, they don't show up, which is a waste and not "reasonable" in size.

Did you have some other answer in mind that you think would help you?

[Starson17]

Originally Posted by jackastor

Actually it doesnt really, but what you say does make better sense.

He said exactly what I said, you just don't seem to understand it.

But the problem is the covers just dont show up regardless.

This is your problem. It has nothing to do with the best size for covers, it's a problem with getting the cover to show up on your specific device. I don't see how playing with the resolution of the cover will help you. You need specific help for this problem with your Kobo Touch.

[PeterT]

Jack... Have you thought of making a sketch in Kobo Sketch or what ever the program is called, copying it to the PC and then openning it in a graphics program and seeing what the dimensions are in pixels of the image?

Seeing I don't have a Touch and find it hard to pry from Sooty's hands I'm unable to try the experiment.

[Starson17]

Originally Posted by PeterT

Jack... Have you thought of making a sketch in Kobo Sketch or what ever the program is called, copying it to the PC and then openning it in a graphics program and seeing what the dimensions are in pixels of the image?

Seeing I don't have a Touch and find it hard to pry from Sooty's hands I'm unable to try the experiment.

Wikipedia says it's a "6-inch, 800x600 Pearl E Ink Display"
I'm still not sure how that helps him. I suspect Calibre is already converting his covers to 800x600 when it recognizes his KT. It might help him a bit if he gets them natively in that size, so that Calibre doesn't have to convert them at all, but from his post, it seems he's intermittently not getting the covers at all.

[theducks]

Originally Posted by Snauzoo

hmmmm... my NOOK says the screen resolution is 600x1024 and there are NO book cover images that size. My problem right now is that my covers are getting chopped off at the bottom and are fatter than they should be. Some of the css in my books has a huge amount of code related to sizing image and it is all mumbo jumbo. I used to go for the largest cover image I could get so they looked good on my iPad. I hate the idea that I have to have a nook library with the same books as the ipad's library so I can have two different cover images! Is there a way around this? And I did think what was said made sense until I realized how high res my nook color is.

Your problem is your style settings are calling for a 100% width on a narrow source (and forgetting to about aspect ratio)
SVG has elements that allow setting Max-width/or Max-Height and preserve aspect ratio

There are 2 crowds:
1) Fill the screen height and width, no matter how distorted the image gets (the Stretch-o-vision crowd)
2) Preserve the Aspect Ratio above all else, even if it results in "bands" on edges (that's me. I used to buy Laser disc movies because they displayed in the Producers chosen Aspect Ratio. )

[jackastor]

TheDucks where are those settings located?
And what do i do to make those changes?


the covers i am using are aprox 417pixels width and 686 hih 300x300 dpi... all go over just dont show up in the touch as a cover and after calibre transfer it then shows as blank.

[jackastor]

Originally Posted by PeterT

Jack... Have you thought of making a sketch in Kobo Sketch or what ever the program is called, copying it to the PC and then openning it in a graphics program and seeing what the dimensions are in pixels of the image?

Seeing I don't have a Touch and find it hard to pry from Sooty's hands I'm unable to try the experiment.

No didnt think of that. Dont think it matters actually as thats got nothing to do with the cover at any rate from what I can see. How ever theducks had some valid information. The covers are 417 pixels width 686 high and 300dpi x300dpi

They are all around that size and resolution always have been. Just no matter what I do those covers only show long enough to load on to the touch and show up in calibres display as being there up untill the touch processes them. then they get turned to blank screens.
The ducks had some interesting comments that are worth investigating and more to the point I think.

Heres a copy of the log for the last book I converted but on the touch its a blank cover now


Convert book 1 of 1 (Second Child)
Resolved conversion options
calibre version: 0.8.11
{'asciiize': False,
'author_sort': None,
'authors': None,
'base_font_size': 0.0,
'book_producer': None,
'change_justification': u'original',
'chapter': u"//*[((name()='h1' or name()='h2') and re:test(., 'chapter|book|section|part|prologue|epilogue\\s+', 'i')) or @class = 'chapter']",
'chapter_mark': u'pagebreak',
'comments': None,
'cover': u'c:\\users\\justme~1.jus\\appdata\\local\\temp\\c alibre_0.8.11_tmp_difguo\\calibre_0.8.11_xokkyb.jp eg',
'debug_pipeline': None,
'dehyphenate': True,
'delete_blank_paragraphs': True,
'disable_font_rescaling': False,
'dont_split_on_page_breaks': False,
'duplicate_links_in_toc': False,
'enable_heuristics': False,
'epub_flatten': False,
'extra_css': None,
'extract_to': None,
'fix_indents': True,
'flow_size': 260,
'font_size_mapping': None,
'format_scene_breaks': True,
'html_unwrap_factor': 0.4,
'input_encoding': None,
'input_profile': <calibre.customize.profiles.InputProfile object at 0x05B329B0>,
'insert_blank_line': False,
'insert_blank_line_size': 0.5,
'insert_metadata': False,
'isbn': None,
'italicize_common_cases': True,
'keep_ligatures': False,
'language': None,
'level1_toc': None,
'level2_toc': None,
'level3_toc': None,
'line_height': 0.0,
'linearize_tables': False,
'margin_bottom': 5.0,
'margin_left': 5.0,
'margin_right': 5.0,
'margin_top': 5.0,
'markup_chapter_headings': True,
'max_toc_links': 50,
'minimum_line_height': 120.0,
'no_chapters_in_toc': False,
'no_default_epub_cover': False,
'no_inline_navbars': False,
'no_svg_cover': False,
'output_profile': <calibre.customize.profiles.GenericEink object at 0x05B32BB0>,
'page_breaks_before': '/',
'prefer_metadata_cover': False,
'preserve_cover_aspect_ratio': True,
'pretty_print': True,
'pubdate': None,
'publisher': None,
'rating': None,
'read_metadata_from_opf': u'c:\\users\\justme~1.jus\\appdata\\local\\temp\\c alibre_0.8.11_tmp_difguo\\calibre_0.8.11_zp5wtt.op f',
'remove_fake_margins': True,
'remove_first_image': False,
'remove_paragraph_spacing': False,
'remove_paragraph_spacing_indent_size': 1.5,
'renumber_headings': True,
'replace_scene_breaks': u'',
'series': None,
'series_index': None,
'smarten_punctuation': False,
'sr1_replace': None,
'sr1_search': None,
'sr2_replace': None,
'sr2_search': None,
'sr3_replace': None,
'sr3_search': None,
'tags': None,
'timestamp': None,
'title': None,
'title_sort': None,
'toc_filter': None,
'toc_threshold': 6,
'unwrap_lines': True,
'use_auto_toc': False,
'verbose': 2}
InputFormatPlugin: EPUB Input running
on c:\users\justme~1.jus\appdata\local\temp\calibre_0 .8.11_tmp_difguo\calibre_0.8.11_4oioqn.epub
Found HTML cover titlepage.xhtml
Parsing all content...
Parsing JSaul%20-%20Second%20Child_split_000.htm ...
Parsing JSaul%20-%20Second%20Child_split_002.htm ...
Parsing JSaul%20-%20Second%20Child_split_001.htm ...
Parsing stylesheet1.css ...
Property: Unknown Property name. [195:5: text-justify-trim]
WARNING:calibre.css:Property: Unknown Property name. [195:5: text-justify-trim]
Parsing JSaul%20-%20Second%20Child_split_004.htm ...
Parsing JSaul%20-%20Second%20Child_split_003.htm ...
Parsing titlepage.xhtml ...
Reading TOC from NCX...
Merging user specified metadata...
Detecting structure...
Flattening CSS and remapping font sizes...
Transformed CSS selector .CM10 to .cm10
Transformed CSS selector .CM11 to .cm11
Transformed CSS selector .CM12 to .cm12
Transformed CSS selector .CM4 to .cm4
Transformed CSS selector .CM5 to .cm5
Transformed CSS selector .CM6 to .cm6
Transformed CSS selector .CM7 to .cm7
Transformed CSS selector .CM8 to .cm8
Transformed CSS selector .CM9 to .cm9
Transformed CSS selector .Default1 to .default1
Transformed CSS selector .MsoNormalTable to .msonormaltable
Transformed CSS selector .MsoNormalTable1 to .msonormaltable1
Transformed CSS selector .MsoNormalTable2 to .msonormaltable2
Transformed CSS selector .MsoNormalTable3 to .msonormaltable3
Transformed CSS selector .MsoNormalTable4 to .msonormaltable4
Transformed CSS selector .CM10 to .cm10
Transformed CSS selector .CM11 to .cm11
Transformed CSS selector .CM12 to .cm12
Transformed CSS selector .CM9 to .cm9
Transformed CSS selector .Default to .default
Transformed CSS selector .Default1 to .default1
Transformed CSS selector .MsoNormalTable2 to .msonormaltable2
Transformed CSS selector .MsoNormalTable3 to .msonormaltable3
Transformed CSS selector .MsoNormalTable4 to .msonormaltable4
Transformed CSS selector .CM10 to .cm10
Transformed CSS selector .CM11 to .cm11
Transformed CSS selector .CM12 to .cm12
Transformed CSS selector .CM8 to .cm8
Transformed CSS selector .MsoNormalTable1 to .msonormaltable1
Transformed CSS selector .MsoNormalTable3 to .msonormaltable3
Transformed CSS selector .MsoNormalTable4 to .msonormaltable4
Transformed CSS selector .CM12 to .cm12
Transformed CSS selector .CM8 to .cm8
Transformed CSS selector .MsoNormalTable1 to .msonormaltable1
Transformed CSS selector .MsoNormalTable3 to .msonormaltable3
Transformed CSS selector .MsoNormalTable4 to .msonormaltable4
Transformed CSS selector .CM10 to .cm10
Transformed CSS selector .CM8 to .cm8
Transformed CSS selector .Default1 to .default1
Transformed CSS selector .MsoNormalTable1 to .msonormaltable1
Transformed CSS selector .MsoNormalTable2 to .msonormaltable2
Source base font size is 12.00000pt
Removing fake margins...
Parsing stylesheet.css ...
Property: Unknown Property name. [215:1: text-justify-trim]
WARNING:calibre.css:Property: Unknown Property name. [215:1: text-justify-trim]
Found 1 items of level: div_1
Found 216 items of level: p_4
Found 1 items of level: div_2
Found 8 items of level: p_2
Found 3913 items of level: p_1
Ignoring level p_2
div_1 left margin stats: Counter({u'': 1})
div_1 right margin stats: Counter({u'': 1})
p_4 left margin stats: Counter({u'0': 216})
p_4 right margin stats: Counter({u'0': 216})
div_2 left margin stats: Counter()
div_2 right margin stats: Counter()
p_1 left margin stats: Counter({u'0': 3913})
p_1 right margin stats: Counter({u'0': 2179, u'6pt': 560, u'12pt': 397, u'0.25in': 248, u'24pt': 198, u'30pt': 113, u'0.5in': 110, u'36pt': 100, u'18.15pt': 3, u'6.15pt': 3, u'17.9pt': 1, u'24.15pt': 1})
Cleaning up manifest...
Trimming unused files from manifest...
Trimming 'cover1.jpeg' from manifest
Trimming 'titlepage.xhtml' from manifest
Creating EPUB Output...
Looking for large trees in JSaul%20-%20Second%20Child_split_000.htm...
No large trees found
Looking for large trees in JSaul%20-%20Second%20Child_split_002.htm...
No large trees found
Looking for large trees in JSaul%20-%20Second%20Child_split_001.htm...
No large trees found
Looking for large trees in JSaul%20-%20Second%20Child_split_004.htm...
No large trees found
Looking for large trees in JSaul%20-%20Second%20Child_split_003.htm...
No large trees found
The cover image has an id != "cover". Renaming to work around bug in Nook Color
EPUB output written to c:\users\justme~1.jus\appdata\local\temp\calibre_0 .8.11_tmp_difguo\calibre_0.8.11_tcrveh.epub



does that help at all anyone?