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Old 03-01-2013, 05:52 AM   #333
dgvirtual
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Posts: 30
Karma: 2848
Join Date: Feb 2013
Location: Lithuania
Device: Kobo Glo
Quote:
Originally Posted by willus View Post
I've never used a Kobo Glo and don't have access to one. I'm not sure what you mean by "vertical fitting." Is this an option on the Glo? It sounds like the page is too tall--wrong aspect ratio. It seems like the dots per inch of the display is about 220 (25.4*768/90.3). Can you experiment with the -w, -h, and -odpi settings? E.g.

k2pdfopt -w 9cm -h 11.3cm -odpi 220 ...

Adjust the values above until you get something you like. Alternatively, you can use pixels for the width and height:

k2pdfopt -w 768 -h 1024 -odpi 220 ...

Let me know and I can add it as a device preset. See also my help page on the topic.
So I edited a picture on my Kobo Glo using the Sketch program included, and found out that the width of the screen is actually 758 px (that is how wide the pictures are). So, the actual dpi is 213. However, the picture does not take all of the screen vertically (a strip on top and a strip on the bottom are left for widgets, etc), so I had to experiment a little more - made jpg pictures of 758px horizontal, and different vertical sizes and tried them on on the screen, as images on Kobo Glo are displayed fullscreen. The result, surprisingly, was that the height is actually 1024px...

Then I measured more or less the bottom strip that is used for illumination widget and page count while reading pdf's, and made some pdf's that use different vertical dimensions.

The best result I got was with these settings:

k2pdfopt -w 758 -h 942 -odpi 213 book.pdf

On Kobo Glo (and Touch - I will do these counts on the Touch later as well) while reading pdf's there is the zoom widget in the bottom panel, but there are also " fit/stretch vertically" and "fit/stretch horizontally" buttons. When using the above mentioned dimensions, pressing any of those widgets does not change the display - that is why I judge that the above parameters make a perfect fit on screen.

Then there is the font size problem - I think that the 12pt Times New Roman in the original document is transformed to look readable on the document, but I do not know what the defaults for your -dev presets usually are. But you can perhaps try it yourself to see by making a document and viewing it on computer screen with a pdf width being 90,4 mm (this seems to be more of an exact measurement if you want to fit all the 658px into 213 dpi - hope I express myself clearly enough
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