Conversion to ePub produces small cover size in Nook library

[CJinPHL]

The ePub file resulting from converting my book from XHTML looks and works fine when viewed in Calibre or Adobe Digital Editions. But when I import the ePub to Nook for PC and view it there, the library view shows a shrunk-down size for the cover, about 1/4 of the size of other books in the library.

When I view the same cover within the book itself, this problem doesn't occur. Any ideas how I can fix this?

[Sirtel]

What is the resolution of the cover image in Calibre?

[davidfor]

It will be the code in the page displaying the image. Odds are, the cover image is smaller and the code is simply putting it in the page without resizing it. The calibre viewer will show the cover page full size as it does not use the code. If it determines that the cover page is just the code to display the image, it simple displays the image.

If you change to cover page to use an SVG wrapper and have it fill the page, it should work better. There are options in the conversion or Polish to do this.

[jhowell]

Originally Posted by CJinPHL

When I view the same cover within the book itself, this problem doesn't occur. Any ideas how I can fix this?

Do you mean the thumbnail image in the library listing, not when you open the book?

Just asking to clarify the problem. I don’t know how the Nook app works.

[JSWolf]

Originally Posted by CJinPHL

The ePub file resulting from converting my book from XHTML looks and works fine when viewed in Calibre or Adobe Digital Editions. But when I import the ePub to Nook for PC and view it there, the library view shows a shrunk-down size for the cover, about 1/4 of the size of other books in the library.

When I view the same cover within the book itself, this problem doesn't occur. Any ideas how I can fix this?

Set the device in the output profile to Tablet. That way images will not be resized.

[CJinPHL]

Originally Posted by Sirtel

What is the resolution of the cover image in Calibre?

Image is 1200 x 1600, 96 dpi

[CJinPHL]

Originally Posted by davidfor

It will be the code in the page displaying the image. Odds are, the cover image is smaller and the code is simply putting it in the page without resizing it. The calibre viewer will show the cover page full size as it does not use the code. If it determines that the cover page is just the code to display the image, it simple displays the image.

If you change to cover page to use an SVG wrapper and have it fill the page, it should work better. There are options in the conversion or Polish to do this.

I don't know much about how Calibre works, but I looked at the file generated by Calibre called titlepage.xhtml. It has an SVG wrapper, but I see it is resizing my file to 563 x 751.

<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 0 563 751" preserveAspectRatio="xMidYMid meet">
<image width="563" height="751" xlink:href="cover.jpeg"/>

I'm going to try editing this code in Calibre to see if that will solve it.

[CJinPHL]

Originally Posted by davidfor

It will be the code in the page displaying the image. Odds are, the cover image is smaller and the code is simply putting it in the page without resizing it. The calibre viewer will show the cover page full size as it does not use the code. If it determines that the cover page is just the code to display the image, it simple displays the image.

If you change to cover page to use an SVG wrapper and have it fill the page, it should work better. There are options in the conversion or Polish to do this.

I don't know much about how Calibre works, but I do see some code created by Calibre in a file called titlepage.xhtml. The SVG wrapper there uses a different file size than the original file size I uploaded. But just editing the code in that file doesn't solve the problem, so it must be happening somewhere else.

[CJinPHL]

Originally Posted by jhowell

Do you mean the thumbnail image in the library listing, not when you open the book?

Just asking to clarify the problem. I don’t know how the Nook app works.

That's exactly what I mean. The cover shows as a small square inside a white box. The white box is the size of other thumbnails in the Nook library.

[DNSB]

Originally Posted by CJinPHL

I don't know much about how Calibre works, but I do see some code created by Calibre in a file called titlepage.xhtml. The SVG wrapper there uses a different file size than the original file size I uploaded. But just editing the code in that file doesn't solve the problem, so it must be happening somewhere else.

Have you tried the suggestion of setting the output profile to tablet to prevent image resizing? Preferences => Conversion => Common Options => Page Setup => Output Profile => Tablet. I also set the Input profile to Default profile.

Your image size in the SVG wrapper suggests you have set an approximately 600x800 device as the Output profile (Generic eInk for example).

[CJinPHL]

Originally Posted by DNSB

Have you tried the suggestion of setting the output profile to tablet to prevent image resizing? Preferences => Conversion => Common Options => Page Setup => Output Profile => Tablet. I also set the Input profile to Default profile.

Your image size in the SVG wrapper suggests you have set an approximately 600x800 device as the Output profile (Generic eInk for example).

This may be a bug in the Nook Windows app when ePub books from sources other than B&N are imported. I tried the solution of setting the Calibre output profile to tablet (also suggested by JSWolf), and now the Calibre-generated SVG wrapper does show the original image size.

However, when viewed in the Nook app, the cover thumbnail still has the same problem as before. (Note that I'm viewing the book in the Nook Windows app, not Nook for PC which I stated previously.)

My guess is that the number of people who will experience this glitch is miniscule, so I'm going to ignore it and go on with my life. Thanks to all for your help!

[davidfor]

Originally Posted by CJinPHL

I don't know much about how Calibre works, but I looked at the file generated by Calibre called titlepage.xhtml. It has an SVG wrapper, but I see it is resizing my file to 563 x 751.

<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 0 563 751" preserveAspectRatio="xMidYMid meet">
<image width="563" height="751" xlink:href="cover.jpeg"/>

I'm going to try editing this code in Calibre to see if that will solve it.

That is the expected code for centring the cover image. Calibre will update the metadata and the cover image when the book is sent to the device. But, it doesn't update the cover page if the image is not the same size as the previous one. So, you might have a much bigger image that is being downscaled.

You can fix this easily in the editor. Again, calibre will update the cover image and metadata when you open the editor (there is an option in the editor to turn this off). You can have calibre regenerate this page . Click the "Tools" in the menu and then "Add cover". You will be prompted to choose the image for the cover and there is an option about whether to preserve the aspect ratio of the cover (the above does not). When you click OK, calibre will replace the existing titlepage.xhtml with a new version with sizing for the current cover image.

If you have a lot of these cases, you can use the Polish books tool to update the covers in a batch. Or if you do the conversion after updating the cover in the library, it will use that when building the epub and it should all be correct.