Re: Screenshots/PNG files in manuals

[Phil Holmes]

----- Original Message ----- 
From: "Phil Holmes" <address@hidden>
To: "Devel" <address@hidden>
Sent: Thursday, August 15, 2013 4:31 PM
Subject: Screenshots/PNG files in manuals


> As I said earlier, I'm working on the tutorial in the LM.  It uses 
> screenshots to show what users will see on the screen.  The versions on 
> the web are (as expected from a pixel-based system) fine.  However, the 
> versions in the PDF docs are badly scaled and look ugly.  It seems that 
> this is generally tackled for images by making them large and then 
> constraining the width in the tex version of the source (this is how it's 
> done in the essay). I'm wondering if there's a better way - is there a 
> recommended pixel-per-inch setting for image files that will end up in the 
> PDFs?  I've looked on the web and couldn't find anything, but am hoping 
> someone will know.
>
> --
> Phil Holmes

I resorted to generating a number of pixel-constrained grids at different 
PPI to try to work this out, and this is what I've found.

The main problem with screenshot-type images in the PDFs is that the viewer 
program scales them badly on screen, and as a result they look bad.  Printed 
output is far better.  However, if the resolution of a screenshot is left at 
its default, then the image in the PDF is far too big.  In my experiments, 
it appears that a setting of 120 pixels per inch gives a good compromise 
between having an image large enough to be legible, and allowing images of a 
reasonable pixel count.  With 120 PPI, the maximum image size is just over 
750 pixels.

I think a small section in the docs section of the CG with this information 
might be worth it?

--
Phil Holmes