PRS-T1 Scaling Images in epubs

mochaiso · 06-06-2012, 02:12 AM

Just thought I'd share this for other PRS-T1 users. I found that a few epubs I downloaded from www.archive.org had images in them that would not scale properly on my PRS-T1 screen. I found an old thread here which discussed the issue but seemed to end without a resolution. The main problem appears to be that Sony readers ignore image sizes specified in points rather than pixels. My solution was two fold using Calibre.

First, do an epub to epub conversion within Calibre, use the "Extra CSS" field in the conversion dialog and paste the following:

.img {min-width:300px; max-width:590px; min-height:300px; max-height:790px}

This is still not good enough because for some reason Calibre still wants to specify image sizes in points. Therefore, after the conversion is completed, "tweak" the book in Calibre, open the stylesheet.css file and use a text editor to find/replace all instances of "pt" to "px". Rebuild the book and sideload it to the reader, all the images should now scale down properly.

pholy · 06-07-2012, 03:34 PM

Quote:

use a text editor to find/replace all instances of "pt" to "px".

And any font sizes specified in points will now be incredibly tiny!

Better to do a search for img tags and change them by hand. Or at least do your search&replace individually and skip the font size changes.

dwig · 06-07-2012, 04:59 PM

Quote:

Originally Posted by mochaiso

...use a text editor to find/replace all instances of "pt" to "px". ...

whoa!!! That would cause some serious damage to most English text. The letter pair "pt" is quite common in English words.

AndrewH · 06-07-2012, 05:18 PM

Quote:

Originally Posted by dwig

whoa!!! That would cause some serious damage to most English text. The letter pair "pt" is quite common in English words.

Quite an apx descrpxion of the problem.

mochaiso · 06-08-2012, 12:33 AM

Hmm. I just converted a ~300 pg book this way and I'm about 1/2 way through with no problems in font size. This particular book had about 50 images in it, that's why I utilized the method described. Maybe you are misunderstanding, I am changing all instances of pt to px in the stylesheet.css file that was generated from specifying Extra CSS in Calibre. There were only images specified in that file under each .calibreXX section.

06-06-2012, 02:12 AM	#1
mochaiso Member Posts: 16 Karma: 14 Join Date: Apr 2012 Device: Sony PRS-T1	Scaling Images in epubs Just thought I'd share this for other PRS-T1 users. I found that a few epubs I downloaded from www.archive.org had images in them that would not scale properly on my PRS-T1 screen. I found an old thread here which discussed the issue but seemed to end without a resolution. The main problem appears to be that Sony readers ignore image sizes specified in points rather than pixels. My solution was two fold using Calibre. First, do an epub to epub conversion within Calibre, use the "Extra CSS" field in the conversion dialog and paste the following: .img {min-width:300px; max-width:590px; min-height:300px; max-height:790px} This is still not good enough because for some reason Calibre still wants to specify image sizes in points. Therefore, after the conversion is completed, "tweak" the book in Calibre, open the stylesheet.css file and use a text editor to find/replace all instances of "pt" to "px". Rebuild the book and sideload it to the reader, all the images should now scale down properly.

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06-08-2012, 12:33 AM	#5
mochaiso Member Posts: 16 Karma: 14 Join Date: Apr 2012 Device: Sony PRS-T1	Hmm. I just converted a ~300 pg book this way and I'm about 1/2 way through with no problems in font size. This particular book had about 50 images in it, that's why I utilized the method described. Maybe you are misunderstanding, I am changing all instances of pt to px in the stylesheet.css file that was generated from specifying Extra CSS in Calibre. There were only images specified in that file under each .calibreXX section.