Re: [boost] Which DPI size for equations in HTML docs?

From: Kevin Lynch (krlynch_at_[hidden])
Date: 2008-03-04 14:52:14

John Maddock wrote:
> By way of experiment I've generated the same equation at various DPI sizes 
> here: http://tinyurl.com/23d74q
> 
> I'd be interested in feedback on which is the best size to use in HTML docs 
> (PDF's get rather better looking SVG versions rendered).
> 
> Thanks! John. 
> 
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The issue you will have, of course, is that you aren't really going to 
render image files at a given "DPI value".  Raster images are measured 
in pixels; it's the final rendering device that has a certain "DPI" 
value.  So people with different resolution screens are going to have 
extremely different feelings on what is "correct" or "best" or even just 
"minimal" "DPI value" for the images.  A "72dpi image" may be good 
enough on an 800x600 display, if it really has a width of (say) 80 
pixels (10% of display width), but the same 80 pixels will be much too 
small on a 1600x1200 display (only 5% of display width); conversely for 
your "150dpi" images, sans scaling.

So, I would suggest rendering the images with a large number of pixels 
(perhaps your 150dpi images), and then relying on the relative scaling 
attributes in the <img> tags (or css, whichever) to make them the 
"right" size.  Most browsers do a pretty good job of downscaling images 
when explicitly requested.  Then everyone can be happy.

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