Quote:
Originally Posted by jhowell
I tried with your image and it works as expected for me.
Did you look for the image in the HDImages folder?
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That prodded me to use KindleUnpack rather then Calibre's viewer to extract the files.
And you're right: in the unpacked files the map is named as a jpeg, but is actually a gif 6 bytes larger than the source. (Using IrfanView to get the specs.)
Quote:
Originally Posted by jhowell
I did a test using kindlegen(Windows) V2.9 build 1029-0897292 with an EPUB containing a 3MB 1800x2681 GIF image. The resulting MOBI has it converted to a 3MB JPEG, still at 1800x2861 resolution.
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-- I think you'll find that is also really a GIF.
So, sorry about that. I had the habit of using Calibre's ebook viewer to check out conversions, but it seems my assumption that it just unpacked and then viewed the file was wrong.
The reason I was checking this out is that the AZW was rather smaller than the epub, when it's usually the other way.
So I looked at the other unpacked AZW images, and found that while the gif was the same, for some jpegs compression had been changed.
e.g.
In the ePub -- 87 kB, quality 98
in the AZW -- 42 kB, quality 80.
The cover image though was the same spec, same size, quality still 98.
So, unless I've made another dumb assumption, it looks like Kindlegen does leave GIFs as-is, and (always?) cover images, but other jpegs may recompress.
And I found earlier that PNGs are converted to either GIFs or JPEGs, which is why I started to use GIFs rather than PNG for most diagrams and maps to keep them sharp.