[REBOL] Re: Display device DPI
From: brett:codeconscious at: 22-Oct-2002 13:56
As far as I understand in general there are no real standards for a
meaningful DPI measure of display screens. For me pixels are the only
meaningful measure of an image on a screen. The simple act of adjusting the
vertical height on a monitor shows that DPI for a screen is a risky concept.
For paper though DPI makes a lot of sense. I was told in a web design course
that a DPI screens was 96dpi (if I remember correctly) but it basically
varied by OS and hardware and the 96dpi was basically to be treated as a
rule of thumb.
I don't know Abiword, I can imagine that a word processor would assume a
printer is the main output device, hence the need to specify sizes in
inches. How it renders a screen representation of the printable document on
screen would be specific to the processor I guess. However it does it, it
will likely be affected by your user's choice of display "Zoom" while
viewing the document as well.
> 4) Do other file formats (eg. PDF, Word, Open Office, etc) have similar
> issues (where the image dimensions are given in a unit of measure other
> than pixels, and a document is generated on one display device and viewed
> on another)?
I imagine so, if the printer is the main output device, then your screen is
only treated as a representation (estimate) of your final output, not the
final output itself.
> 5) Am I just approaching this from the wrong POV?
I'm not entirely clear what your goal is. If it is important that on screen
image is very accurate then you probably need a different application from a
word processor to render it properly. Alternatively maybe you can arrange it
so that your documents with images are always viewed at 100% and ensure that
your images do not need scaling in this situation (Ie prescale them).