degraded cover image in Nook for PC and ADE

SantafA · 03-17-2015, 04:07 AM

I'm stumped. Again : )

I have a jpeg, 1400px x 2000px, 150ppi, for my cover image. It's a good quality image and looks good when viewed in Photoshop and Windows Photo Viewer.

When I open my book in Nook for PC or ADE though, the cover looks like crap. The colors are muted and the text no longer looks strong and sharp - the small text looks shaky and jagged, and the big text no longer looks anti-aliased either. I suppose this must be caused by being displayed at a lower resolution. Though I don't really know.

I didn't use any program to insert the cover image into my book. I did it manually by creating a new xhtml page for just the cover image and writing the css. I didn't use any program that I think might compress the image. And I don't believe there is anything in my css that would compress it. Though maybe I am wrong.

The cover image actually looks fine when I open the book in Calibre.

Do Nook for PC and ADE compress images automatically? What am I missing?

Here's my code for the image:

XHTML

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>cover</title>
<link href="css/idGeneratedStyles.css" rel="stylesheet" type="text/css" />
</head>
<body class="cover">
<p class="cover"><img class="cover" alt="" src="cover-e-epub.jpg" /></p>
</body>
</html>

CSS

body.cover {
oeb-column-number: 1;
margin: 0;
padding: 0;
text-align: center;
}
p.cover {
height:99%;
width:100%;
text-align:center;
page-break-inside:avoid;
}
img.cover {
display:inline-block;
height:100%;
margin:0 auto;
}

The cover looked the same way actually when I put the image in using an SVG method though. That seems to rule out the problem being in the xhtml or css code. But again, I don't know.

Thank you everyone.

Jellby · 03-17-2015, 04:18 AM

First of all, don't use JPG for this kind of image, use PNG, it will be smaller and look nicer. (But do not convert the JPG to PNG!).

The resize in ADE is probably simple and crappy, and there's nothing you can do about it other than using a smaller image that will not be resized. About the colours, that might be due to some gamma or colour profile not being interpreted by ADE.

SantafA · 03-17-2015, 04:56 AM

Thanks for responding so fast, Jellby!

The sample is a small part of the cover, it has some smooth gradation elsewhere.

I'm still getting the same "resolution" problem using a png. I resized it to 980 x 1400 and still same problem. What you said makes sense though. I'll try messing around with it more tomorrow.

For the jpeg color I'm using Adobe RGB 1998, which is what Kindle recommends for mobis. I don't know what Nook or ADE recommend. Do you have a recommendation?

Jellby · 03-17-2015, 06:56 AM

Quote:

Originally Posted by SantafA

The sample is a small part of the cover, it has some smooth gradation elsewhere.

Still, if it has sharp, clean edges, PNG may be better suited. Try saving the original as both PNG and JPG. If the PNG is not much larger than the JPG, always prefer the PNG, since it's lossless.

Quote:

I'm still getting the same "resolution" problem using a png. I resized it to 980 x 1400 and still same problem. What you said makes sense though. I'll try messing around with it more tomorrow.

PNG or JPG should make no practical difference regarding resizing artifacts, and the only way to avoid them is to avoid resizing at all. Try with less than 800 height.

Quote:

For the jpeg color I'm using Adobe RGB 1998, which is what Kindle recommends for mobis. I don't know what Nook or ADE recommend. Do you have a recommendation?

I have no idea, but I would guess ADE simply ignores any kind of embedded color profile or gamma information. So try saving without that .

Toxaris · 03-17-2015, 07:53 AM

The downscaling algorithm in ADE is not that good. However, I usually have much better results when I put the cover in the SVG wrapper. Somehow it seems that the resize algorithm is better then. The SVG wrapper can be found all over. Sigil also uses that code when inserting a cover.

DomesticExtremis · 03-17-2015, 10:08 AM

Quote:

Originally Posted by SantafA

For the jpeg color I'm using Adobe RGB 1998, which is what Kindle recommends for mobis. I don't know what Nook or ADE recommend. Do you have a recommendation?

The 'standard' for web (html/css) and by implication for ePub is sRGB.
If your picture is encoded with something else then decoded using sRGB,
colour fidelity issues will almost certainly arise.

Try saving the image with sRGB profile and see if that helps.

DaleDe · 03-17-2015, 01:18 PM

Quote:

Originally Posted by DomesticExtremis

The 'standard' for web (html/css) and by implication for ePub is sRGB.
If your picture is encoded with something else then decoded using sRGB,
colour fidelity issues will almost certainly arise.

Try saving the image with sRGB profile and see if that helps.

Probably not - See http://kenrockwell.com/tech/adobe-rgb.htm

Dale

DomesticExtremis · 03-19-2015, 04:51 PM

Quote:

Originally Posted by DaleDe

Probably not - See http://kenrockwell.com/tech/adobe-rgb.htm

Dale

Then again (from your link):

Quote:

...
Adobe RGB theoretically can represent a wider range (gamut) of colors, however:

1.) Adobe RGB requires special software and painstaking workflow not to screw it up. Make one mistake anyplace and you get dull colors, or worse. You cannot use Adobe RGB on the internet or for email or conventional photo lab printing. If you do, the colors are duller.

2.) I've made Lightjet, Fuji Supergloss and inkjet prints of 100% saturated ramps in both color spaces. I saw the same color range in print with each colorspace. I saw no real gain of any wider gamut in practice, even with these special tests.
...

Hitch · 03-24-2015, 07:24 PM

Quote:

Originally Posted by SantafA

I'm stumped. Again : )

I have a jpeg, 1400px x 2000px, 150ppi, for my cover image. It's a good quality image and looks good when viewed in Photoshop and Windows Photo Viewer.

When I open my book in Nook for PC or ADE though, the cover looks like crap. The colors are muted and the text no longer looks strong and sharp - the small text looks shaky and jagged, and the big text no longer looks anti-aliased either. I suppose this must be caused by being displayed at a lower resolution. Though I don't really know.

I didn't use any program to insert the cover image into my book. I did it manually by creating a new xhtml page for just the cover image and writing the css. I didn't use any program that I think might compress the image. And I don't believe there is anything in my css that would compress it. Though maybe I am wrong.

The cover image actually looks fine when I open the book in Calibre.

Do Nook for PC and ADE compress images automatically? What am I missing?

Here's my code for the image:

XHTML

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>cover</title>
<link href="css/idGeneratedStyles.css" rel="stylesheet" type="text/css" />
</head>
<body class="cover">
<p class="cover"><img class="cover" alt="" src="cover-e-epub.jpg" /></p>
</body>
</html>

CSS

body.cover {
oeb-column-number: 1;
margin: 0;
padding: 0;
text-align: center;
}
p.cover {
height:99%;
width:100%;
text-align:center;
page-break-inside:avoid;
}
img.cover {
display:inline-block;
height:100%;
margin:0 auto;
}

The cover looked the same way actually when I put the image in using an SVG method though. That seems to rule out the problem being in the xhtml or css code. But again, I don't know.

Thank you everyone.

Did you anti-alias the fonts?

Hitch

03-17-2015, 04:07 AM	#1
SantafA Member Posts: 13 Karma: 10 Join Date: Mar 2015 Device: none	degraded cover image in Nook for PC and ADE I'm stumped. Again : ) I have a jpeg, 1400px x 2000px, 150ppi, for my cover image. It's a good quality image and looks good when viewed in Photoshop and Windows Photo Viewer. When I open my book in Nook for PC or ADE though, the cover looks like crap. The colors are muted and the text no longer looks strong and sharp - the small text looks shaky and jagged, and the big text no longer looks anti-aliased either. I suppose this must be caused by being displayed at a lower resolution. Though I don't really know. I didn't use any program to insert the cover image into my book. I did it manually by creating a new xhtml page for just the cover image and writing the css. I didn't use any program that I think might compress the image. And I don't believe there is anything in my css that would compress it. Though maybe I am wrong. The cover image actually looks fine when I open the book in Calibre. Do Nook for PC and ADE compress images automatically? What am I missing? Here's my code for the image: XHTML <?xml version="1.0" encoding="UTF-8" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>cover</title> <link href="css/idGeneratedStyles.css" rel="stylesheet" type="text/css" /> </head> <body class="cover"> <p class="cover"><img class="cover" alt="" src="cover-e-epub.jpg" /></p> </body> </html> CSS body.cover { oeb-column-number: 1; margin: 0; padding: 0; text-align: center; } p.cover { height:99%; width:100%; text-align:center; page-break-inside:avoid; } img.cover { display:inline-block; height:100%; margin:0 auto; } The cover looked the same way actually when I put the image in using an SVG method though. That seems to rule out the problem being in the xhtml or css code. But again, I don't know. Thank you everyone. Attached Thumbnails Last edited by SantafA; 03-17-2015 at 01:07 PM.

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03-17-2015, 04:18 AM	#2
Jellby frumious Bandersnatch Posts: 7,515 Karma: 18512745 Join Date: Jan 2008 Location: Spaniard in Sweden Device: Cybook Orizon, Kobo Aura	First of all, don't use JPG for this kind of image, use PNG, it will be smaller and look nicer. (But do not convert the JPG to PNG!). The resize in ADE is probably simple and crappy, and there's nothing you can do about it other than using a smaller image that will not be resized. About the colours, that might be due to some gamma or colour profile not being interpreted by ADE.

03-17-2015, 04:56 AM	#3
SantafA Member Posts: 13 Karma: 10 Join Date: Mar 2015 Device: none	Thanks for responding so fast, Jellby! The sample is a small part of the cover, it has some smooth gradation elsewhere. I'm still getting the same "resolution" problem using a png. I resized it to 980 x 1400 and still same problem. What you said makes sense though. I'll try messing around with it more tomorrow. For the jpeg color I'm using Adobe RGB 1998, which is what Kindle recommends for mobis. I don't know what Nook or ADE recommend. Do you have a recommendation?

03-17-2015, 07:53 AM	#5
Toxaris Wizard Posts: 4,520 Karma: 121692313 Join Date: Oct 2009 Location: Heemskerk, NL Device: PRS-T1, Kobo Touch, Kobo Aura	The downscaling algorithm in ADE is not that good. However, I usually have much better results when I put the cover in the SVG wrapper. Somehow it seems that the resize algorithm is better then. The SVG wrapper can be found all over. Sigil also uses that code when inserting a cover.