Image conversion changed btwn 6.14.1 and 7.12.0

[Quoth]

You can use a compromise size for all ebooks and a different size for POD, or even the same for them all.

I'd not use actual Adobe Photoshop now as it's too expensive. There are many good enough free tools. Not used Photoshop for years.

These are clearly what are required. And again these are based on the output that I was getting from Calibre 6.14.1 and which produce an output that looks good on the specified platforms.

No, they are not. As these are larger images a percent is needed. Kobo has not just 300 dpi, but 6" and 6.8" screens with lower DPI.

Apple has phones and tablets.

We distribute the same content (same file inc images) to Amazon, Apple, Barnes & Nobel, Google Playbooks, Kobo, Tolino etc.

I used to use Paint Shop Pro7 and still MS Word after Photoshop, then changed to The GIMP (go first to settings and make the GUI, toolbox and Icon theme sane) and LO Writer. This was still on XP. I used Win7 for a while and then changed to Linux Mint with Mate Desktop.

I had to export all my PSP7 files as Photoshop for The GIMP to read them.

There is nothing wrong with Calibre. It's brilliant for converting docx to epub2 and leaving the images exactly as they are. Then I do some CSS edit (with preview).
The css sections with auto all had pt on the Calibre conversion from docx.

.calibre1 {
  height: auto;
  width: 66.67%;
}
.calibre2 {
  height: 45pt;
  width: 70.3pt;
}
.calibre3 {
  text-decoration: none;
}
.calibre4 {
  height: 43.1pt;
  width: 43.1pt;
}
.calibre5 {
  display: block;
}
.calibre6 {
  height: auto;
  width: 75%;
}
.calibre7 {
  height: auto;
  width: 20%;
}
.calibre8 {
  font-style: italic;
}
.calibre9 {
  height: auto;
  width: 80%;
}
.calibre10 {
  height: auto;
  width: 50%;
}
.calibre11 {
  height: auto;
  width: 66.67%;
}
.text_ {
  color: #000080;
  text-decoration: underline solid;
}

Some small images are left as pt, because


Text and margins and padding can be in pt or em. By default 12 pt = 1em, though kepub may not use that for margins.

A px is not a pixel. A 1 px line is "the finest line to render without anti-aliasing" (may not be quite true).
Images should use px or % or auto, but pt may work well for small images. In this case 12pt = 16 px if the renderer doesn't scale images in pt. On some apps/ereaders the image is scalled with font if it's set in pt. It's never scaled if it's in px.

There is no pixel setting.

A body font is assumed to be 1em if not stated and the user can increase or decrease, but unlike zoom on PDF, everything reflows and margins, padding and line spacing change, assuming line spacing isn't set.
Never set line spacing for an ebook (that's for web pages and paper). The spacing is then set by font size and font metrics.

Never use cm, inch etc for anything, those are for paper.

Never use px for fonts, margins or padding. Use em, pt (12 pt = 1em) or % (100% = 1em).

Web pages don't work exactly the same. Calibre viewer and some other ereader apps are really web browsers using ebook-like rules, so sometimes behave differently to physical ereaders. Kindle AZW3 is much like epub2. The Kindle KFX and Kobo kepub handle text spacing and kerning a bit different and may allow image zoom.

We proof as epub2 and copy/paste wordprocessor content for epub into a new template for paper POD.

The epub3 can be similar to epub2, or be quite diifferent. Some of the epub3 features just mimic PDF and others mimic a multimedia framework.

I edit odt files with an extra docx only for Calibre. I used to interchange docx, but the others are all now using LO Writer instead of Word. Traditional publishers want docx. Self-publishing entirely uses epub2 (though other formats possible) for real ebooks (reflowable & no multimedia/interactive) and pdf for POD or fixed layout.

We don't deal with Apple (painful), Kobo, Barnes & Noble etc direct, but via Smashwords/Direct2Digital. Amazon and Google get separate uploads.

Amazon unfortunately has over 92% of English Language title sales world-wide and Google mysteriously tiny. We've had almost as many sales on non-Amazon (all combined) as Amazon and none on Google! So I suspect many are only uploading to Amazon.

[JSWolf]

Originally Posted by jdg-calibre

Would you then suggest that the images should be resized in a tool like Photoshop and the dimensions that I would want to resize them to be the same dimensions that I have found are needed/acceptable for each of the platforms I am targeting? That is to use the dimensions I mentioned in my last post for each of the images, e.g. :

Apple: 749x842 for Map of England
B&N: 576x648 for Map of England
Kobo: 512x576 for Map of England

These are clearly what are required. And again these are based on the output that I was getting from Calibre 6.14.1 and which produce an output that looks good on the specified platforms.

I certainly can do this, but I am wondering what is wrong with the output of the images from Calibre. What is wrong with the reduced images output from Calibre?

All of your specified resolutions are too small. You need a hi-res image to be of any use. Especially for an image you actually read. You need at least 1600 lines to be of any real use.

[theducks]

Note those opinions above are those of the poster.
Your clients are the ones that count. (even if they are wrong. Just get it in writing so you get paid)

Also note: Basic Physics is still the rule.
Smaller, means something was REMOVED. Once gone, it is gone. (from that copy. Always keep a HiRes master handy)

Thus, making it B I G G E R requires something be put IN those gaps or you get something like I just did. It takes a ton of computing to upscale with the best guess blend the fill.

[JSWolf]

Originally Posted by theducks

Note those opinions above are those of the poster.
Your clients are the ones that count. (even if they are wrong. Just get it in writing so you get paid)

Also note: Basic Physics is still the rule.
Smaller, means something was REMOVED. Once gone, it is gone. (from that copy. Always keep a HiRes master handy)

Thus, making it B I G G E R requires something be put IN those gaps or you get something like I just did. It takes a ton of computing to upscale with the best guess blend the fill.

They are not wrong ad they are not opinions. When you have maps, they need to be hi-res.

I've seen too many maps that are too small and unreadable.

[jdg-calibre]

If you would like to see what the maps look like on Apple devices, you can look at the sample for the upcoming book (or the sample for any book for that matter if you want to poke around) here:

https://geo.itunes.apple.com/us/book...17355119?mt=11

Or for the previous book on Kindle/Amazon look at the sample:

https://www.amazon.com/Water-Borne-B...dp/B0BTVZKDC8/

To me the maps in the samples, which are the same as in the complete books, look fine, especially on Kindle which is manipulating the images on their own from the docx which has the full images to use for scaling.

For the other platforms, Apple, Kobo and Barnes & Noble, the maps are what used to be generated from Calibre 6x and are what I would be using going forward with Calibre 7x and the setting for adjusting images.

I get what you are talking about, but we have never had someone complain about the quality of the images and as these are the only images (the maps) in all of the books it does not seem necessary to spend more time on the images.

Now if the books were more about the images I can understand how handling the images as you suggest would be more relevant.

Again I thank you for taking the time to clarify your process and recommendations.

Best regards,
Jonathan

Originally Posted by Quoth

You can use a compromise size for all ebooks and a different size for POD, or even the same for them all.

I'd not use actual Adobe Photoshop now as it's too expensive. There are many good enough free tools. Not used Photoshop for years.


No, they are not. As these are larger images a percent is needed. Kobo has not just 300 dpi, but 6" and 6.8" screens with lower DPI.

Apple has phones and tablets.

We distribute the same content (same file inc images) to Amazon, Apple, Barnes & Nobel, Google Playbooks, Kobo, Tolino etc.

I used to use Paint Shop Pro7 and still MS Word after Photoshop, then changed to The GIMP (go first to settings and make the GUI, toolbox and Icon theme sane) and LO Writer. This was still on XP. I used Win7 for a while and then changed to Linux Mint with Mate Desktop.

I had to export all my PSP7 files as Photoshop for The GIMP to read them.

There is nothing wrong with Calibre. It's brilliant for converting docx to epub2 and leaving the images exactly as they are. Then I do some CSS edit (with preview).
The css sections with auto all had pt on the Calibre conversion from docx.

.calibre1 {
  height: auto;
  width: 66.67%;
}
.calibre2 {
  height: 45pt;
  width: 70.3pt;
}
.calibre3 {
  text-decoration: none;
}
.calibre4 {
  height: 43.1pt;
  width: 43.1pt;
}
.calibre5 {
  display: block;
}
.calibre6 {
  height: auto;
  width: 75%;
}
.calibre7 {
  height: auto;
  width: 20%;
}
.calibre8 {
  font-style: italic;
}
.calibre9 {
  height: auto;
  width: 80%;
}
.calibre10 {
  height: auto;
  width: 50%;
}
.calibre11 {
  height: auto;
  width: 66.67%;
}
.text_ {
  color: #000080;
  text-decoration: underline solid;
}

Some small images are left as pt, because


Text and margins and padding can be in pt or em. By default 12 pt = 1em, though kepub may not use that for margins.

A px is not a pixel. A 1 px line is "the finest line to render without anti-aliasing" (may not be quite true).
Images should use px or % or auto, but pt may work well for small images. In this case 12pt = 16 px if the renderer doesn't scale images in pt. On some apps/ereaders the image is scalled with font if it's set in pt. It's never scaled if it's in px.

There is no pixel setting.

A body font is assumed to be 1em if not stated and the user can increase or decrease, but unlike zoom on PDF, everything reflows and margins, padding and line spacing change, assuming line spacing isn't set.
Never set line spacing for an ebook (that's for web pages and paper). The spacing is then set by font size and font metrics.

Never use cm, inch etc for anything, those are for paper.

Never use px for fonts, margins or padding. Use em, pt (12 pt = 1em) or % (100% = 1em).

Web pages don't work exactly the same. Calibre viewer and some other ereader apps are really web browsers using ebook-like rules, so sometimes behave differently to physical ereaders. Kindle AZW3 is much like epub2. The Kindle KFX and Kobo kepub handle text spacing and kerning a bit different and may allow image zoom.

We proof as epub2 and copy/paste wordprocessor content for epub into a new template for paper POD.

The epub3 can be similar to epub2, or be quite diifferent. Some of the epub3 features just mimic PDF and others mimic a multimedia framework.

I edit odt files with an extra docx only for Calibre. I used to interchange docx, but the others are all now using LO Writer instead of Word. Traditional publishers want docx. Self-publishing entirely uses epub2 (though other formats possible) for real ebooks (reflowable & no multimedia/interactive) and pdf for POD or fixed layout.

We don't deal with Apple (painful), Kobo, Barnes & Noble etc direct, but via Smashwords/Direct2Digital. Amazon and Google get separate uploads.

Amazon unfortunately has over 92% of English Language title sales world-wide and Google mysteriously tiny. We've had almost as many sales on non-Amazon (all combined) as Amazon and none on Google! So I suspect many are only uploading to Amazon.