Cover image bug with ePub for correct aspect

JSWolf · 01-23-2011, 06:27 PM

When I convert something to ePub and add in a cover image, the cover comes out wrong. The aspect is wrong.

The titlepage file has 600x800 resolution and that makes the cover the full width of the screen instead of aspect correct. Sure I can go in and change the resolution to the image's but I should not have to. I am using ebook-convert.

Code:

ebook-convert %1 .epub margin-top=0 --margin-bottom=0 --margin-left=0 --margin-right=0 --preserve-cover-aspect-ratio --cover=cover.jpg --language=en

As you can see by the specified options, I am specifying to keep the aspect ratio and it's failing.

ldolse · 01-23-2011, 11:01 PM

I don't know much about that variable and how that particular area of the code works, but I know that when I enable/disable 'preserve aspect ratio' from the GUI it works as expected. Maybe do a GUI conversion and see if there are extra arguments you need to pass to the command line? All the arguments that get passed are documented in the job details.

JSWolf · 01-24-2011, 04:25 PM

Quote:

Originally Posted by ldolse

I don't know much about that variable and how that particular area of the code works, but I know that when I enable/disable 'preserve aspect ratio' from the GUI it works as expected. Maybe do a GUI conversion and see if there are extra arguments you need to pass to the command line? All the arguments that get passed are documented in the job details.

That won't work. I don't use the GUI. I use the command line. Looks like I am going to have to file a bug report.

Manichean · 01-25-2011, 04:34 AM

I think what he's trying to say is that you should do a test case conversion in the GUI for the purpose of figuring out which arguments the GUI uses. There may be issues with the arguments you pass to ebook-convert, for example, I could see the margin=0- arguments fighting with the preserve-aspect-ratio argument and winning. If you converted via the GUI as a test, you'd be able to see, for example, if the margin arguments still get passed when you select to preserve aspect ratio.

JSWolf · 01-25-2011, 09:12 AM

Quote:

Originally Posted by ldolse

I don't know much about that variable and how that particular area of the code works, but I know that when I enable/disable 'preserve aspect ratio' from the GUI it works as expected. Maybe do a GUI conversion and see if there are extra arguments you need to pass to the command line? All the arguments that get passed are documented in the job details.

Can you do me a favor? Convert something to ePub with a new cover image and specify to keep the aspect ratio. Then ZIP the file titlepage.xhtml and attach it to this thread so I can have a look please. Thanks.

ldolse · 01-25-2011, 09:33 AM

Sure, titlepage:

Code:

<?xml version='1.0' encoding='utf-8'?>
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
        <meta name="calibre:cover" content="true"/>
        <title>Cover</title>
        <style type="text/css" title="override_css">
            @page {padding: 0pt; margin:0pt}
            body { text-align: center; padding:0pt; margin: 0pt; }
        </style>
    </head>
    <body>
        <div>
            <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="100%" height="100%" viewBox="0 0 600 800" preserveAspectRatio="xMidYMid meet">
                <image width="600" height="800" xlink:href="cover.jpeg"/>
            </svg>
        </div>
    </body>
</html>

Verified in ADE that the aspect ratio is preserved.

Here are the conversion options that were resolved:

Code:

Convert book 1 of 1 (Ulysses)
Resolved conversion options
calibre version: 0.7.42
{'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\\s+', 'i')) or @class = 'chapter']",
 'chapter_mark': u'pagebreak',
 'comments': None,
 'cover': '/var/folders/Rm/Rm6mzVkCH6GuTtIFsFdGnU+++TI/-Tmp-/calibre_0.7.42_tmp_aO8HwV/calibre_0.7.42_VEtwPB.jpeg',
 'debug_pipeline': None,
 'dehyphenate': True,
 'delete_blank_paragraphs': True,
 'disable_font_rescaling': False,
 'dont_split_on_page_breaks': 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 0x106fdb690>,
 'insert_blank_line': False,
 '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.SonyReaderOutput object at 0x106fdbe90>,
 'page_breaks_before': u"//*[name()='h1' or name()='h2']",
 'prefer_metadata_cover': False,
 'preserve_cover_aspect_ratio': True,
 'pretty_print': True,
 'pubdate': None,
 'publisher': None,
 'rating': None,
 'read_metadata_from_opf': '/var/folders/Rm/Rm6mzVkCH6GuTtIFsFdGnU+++TI/-Tmp-/calibre_0.7.42_tmp_aO8HwV/calibre_0.7.42_UFn_ZV.opf',
 'remove_first_image': False,
 'remove_paragraph_spacing': False,
 'remove_paragraph_spacing_indent_size': 1.5,
 'renumber_headings': True,
 '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}

Manichean was correct, btw, I didn't intend for you to switch over to the GUI, just use it for debugging.

JSWolf · 01-25-2011, 03:06 PM

I can see the bug right there. The aspect ratio is wrong because the resolution is set to 600x800. So you get your image set to fit as though it was a 600x800 resolution image. When I change 600 and 800 to the actual resolution of the cover image, then I get the correct aspect ratio.

Code:

<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="100%" height="100%" viewBox="0 0 600 800" preserveAspectRatio="xMidYMid meet">
                <image width="600" height="800" xlink:href="cover.jpeg"/>

kovidgoyal · 01-25-2011, 03:31 PM

No width and height are set to 600x800 only when preserve aspect ratio is set, which in turn sets the preserveAspectRatio property of the container <svg> element to xMidYMid meet which means that a compliant svg renderer has to render the image within the viewbox (which is also set to 600x800 while preserving the aspect ratio)

Use an epub viewer that properly implements the SVG spec, like calibre's epub viewer and you will see that the aspect ratio is indeed preserved.

JSWolf · 01-27-2011, 12:54 PM

Quote:

Originally Posted by kovidgoyal

No width and height are set to 600x800 only when preserve aspect ratio is set, which in turn sets the preserveAspectRatio property of the container <svg> element to xMidYMid meet which means that a compliant svg renderer has to render the image within the viewbox (which is also set to 600x800 while preserving the aspect ratio)

Use an epub viewer that properly implements the SVG spec, like calibre's epub viewer and you will see that the aspect ratio is indeed preserved.

So if I don't set things to preserve the aspect ratio, then it will actually work in ADE? The problem with Calibre's ePub renderer is that it's not on my 650 so I cannot use it. Needs to work with ADE.

kovidgoyal · 01-27-2011, 01:06 PM

Try it and see.

ldolse · 01-27-2011, 01:29 PM

My epub's covers all render fine with ADE - desktop and my Sony devices - of course it generally looks wonky on my desktop because the ADE window is generally set to a different aspect ratio than my reader, but they do render as configured. I prefer Calibre's default as that way there are no borders and the image fully fills the reader screen.

JSWolf · 01-27-2011, 06:13 PM

Quote:

Originally Posted by ldolse

My epub's covers all render fine with ADE - desktop and my Sony devices - of course it generally looks wonky on my desktop because the ADE window is generally set to a different aspect ratio than my reader, but they do render as configured. I prefer Calibre's default as that way there are no borders and the image fully fills the reader screen.

You just don't see that the aspect ratio is incorrect. But trust me, it is.

JSWolf · 01-27-2011, 06:22 PM

Quote:

Originally Posted by kovidgoyal

Try it and see.

I tried it and it made the image way too wide. Now, I found the solution.

Code:

<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="100%" height="100%" viewBox="0 0 600 800" preserveAspectRatio="xMidYMid meet">
                <image width="600" height="800" xlink:href="cover.jpeg"/>

If you change the 600 and 800 to the actual resolution of the image, then it works perfectly in ebook-viewer and in ADE. So fixing it to work in ADE does not break it in ebook-viewer.

kovidgoyal · 01-27-2011, 06:25 PM

I am unable to replicate this ADE on my machine is not changing the aspect ratio of cover images as long as preserveAspectRatio is set to xmidymid meet.

What version of ade/device are you seeing this on?

JSWolf · 01-28-2011, 09:15 AM

I'm seeing this on my 650 and on Windows ADE 1.7.2.1131

The first attachment (cover.jpg) is the cover being shown in the correct aspect ratio in ACDSee.

The second (cover2.png) is the cover as it comes out of Calibre with the aspect ratio is supposed to be preserved.

The third (cover3.jpg) is showing the cover in ADE with the correct aspect ratio when I change the numbers from 600 800 to the size of the image.

As you can see, 800 600 gives an incorrect aspect ratio while using the images size gives me the correct aspect ratio.

01-23-2011, 06:27 PM	#1
JSWolf Resident Curmudgeon Posts: 73,877 Karma: 128597114 Join Date: Nov 2006 Location: Roslindale, Massachusetts Device: Kobo Libra 2, Kobo Aura H2O, PRS-650, PRS-T1, nook STR, PW3	Cover image bug with ePub for correct aspect When I convert something to ePub and add in a cover image, the cover comes out wrong. The aspect is wrong. The titlepage file has 600x800 resolution and that makes the cover the full width of the screen instead of aspect correct. Sure I can go in and change the resolution to the image's but I should not have to. I am using ebook-convert. Code: ebook-convert %1 .epub margin-top=0 --margin-bottom=0 --margin-left=0 --margin-right=0 --preserve-cover-aspect-ratio --cover=cover.jpg --language=en As you can see by the specified options, I am specifying to keep the aspect ratio and it's failing.

01-25-2011, 03:06 PM	#7
JSWolf Resident Curmudgeon Posts: 73,877 Karma: 128597114 Join Date: Nov 2006 Location: Roslindale, Massachusetts Device: Kobo Libra 2, Kobo Aura H2O, PRS-650, PRS-T1, nook STR, PW3	I can see the bug right there. The aspect ratio is wrong because the resolution is set to 600x800. So you get your image set to fit as though it was a 600x800 resolution image. When I change 600 and 800 to the actual resolution of the cover image, then I get the correct aspect ratio. Code: <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="100%" height="100%" viewBox="0 0 600 800" preserveAspectRatio="xMidYMid meet"> <image width="600" height="800" xlink:href="cover.jpeg"/> Last edited by JSWolf; 01-25-2011 at 03:10 PM.

01-28-2011, 09:15 AM	#15
JSWolf Resident Curmudgeon Posts: 73,877 Karma: 128597114 Join Date: Nov 2006 Location: Roslindale, Massachusetts Device: Kobo Libra 2, Kobo Aura H2O, PRS-650, PRS-T1, nook STR, PW3	I'm seeing this on my 650 and on Windows ADE 1.7.2.1131 The first attachment (cover.jpg) is the cover being shown in the correct aspect ratio in ACDSee. The second (cover2.png) is the cover as it comes out of Calibre with the aspect ratio is supposed to be preserved. The third (cover3.jpg) is showing the cover in ADE with the correct aspect ratio when I change the numbers from 600 800 to the size of the image. As you can see, 800 600 gives an incorrect aspect ratio while using the images size gives me the correct aspect ratio. Attached Thumbnails

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Auto-creation of cover image on .epub to .mobi conversion	december	Calibre	4	02-10-2012 05:31 PM
[Old Thread] Epub cover image does not display correctly	Amalthia	Calibre	30	06-20-2011 11:50 AM
Epub cover image issue	vipinpa	ePub	18	05-25-2010 12:28 AM
epub conversion - cover image	Nate the great	Calibre	15	09-14-2009 05:15 PM
Aspect ratio of Kindle cover art?	Skydog	Kindle Formats	7	06-02-2009 04:46 PM

01-23-2011, 11:01 PM	#2
ldolse Wizard Posts: 1,337 Karma: 123455 Join Date: Apr 2009 Location: Malaysia Device: PRS-650, iPhone	I don't know much about that variable and how that particular area of the code works, but I know that when I enable/disable 'preserve aspect ratio' from the GUI it works as expected. Maybe do a GUI conversion and see if there are extra arguments you need to pass to the command line? All the arguments that get passed are documented in the job details.

01-25-2011, 04:34 AM	#4
Manichean Wizard Posts: 3,130 Karma: 91256 Join Date: Feb 2008 Location: Germany Device: Cybook Gen3	I think what he's trying to say is that you should do a test case conversion in the GUI for the purpose of figuring out which arguments the GUI uses. There may be issues with the arguments you pass to ebook-convert, for example, I could see the margin=0- arguments fighting with the preserve-aspect-ratio argument and winning. If you converted via the GUI as a test, you'd be able to see, for example, if the margin arguments still get passed when you select to preserve aspect ratio.

01-25-2011, 03:31 PM	#8
kovidgoyal creator of calibre Posts: 43,835 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	No width and height are set to 600x800 only when preserve aspect ratio is set, which in turn sets the preserveAspectRatio property of the container <svg> element to xMidYMid meet which means that a compliant svg renderer has to render the image within the viewbox (which is also set to 600x800 while preserving the aspect ratio) Use an epub viewer that properly implements the SVG spec, like calibre's epub viewer and you will see that the aspect ratio is indeed preserved.

01-27-2011, 01:06 PM	#10
kovidgoyal creator of calibre Posts: 43,835 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	Try it and see.

01-27-2011, 01:29 PM	#11
ldolse Wizard Posts: 1,337 Karma: 123455 Join Date: Apr 2009 Location: Malaysia Device: PRS-650, iPhone	My epub's covers all render fine with ADE - desktop and my Sony devices - of course it generally looks wonky on my desktop because the ADE window is generally set to a different aspect ratio than my reader, but they do render as configured. I prefer Calibre's default as that way there are no borders and the image fully fills the reader screen.

01-27-2011, 06:25 PM	#14
kovidgoyal creator of calibre Posts: 43,835 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	I am unable to replicate this ADE on my machine is not changing the aspect ratio of cover images as long as preserveAspectRatio is set to xmidymid meet. What version of ade/device are you seeing this on?

Advert

Advert