[clue-tech] screen shots

[Jim Ockers]

Hi Jeff,

> I'm looking for gimp advice.
> 
> I would like to use clear screen shots in printed materials.  The issues that 
> I haven't figured out are:
> 
> 1.  How can I take a screen shot at a higher resolution?  For example, if my 
> screen is 92 DPI and I want to print at 300 DPI, how can I grab a screen 
> shot?  

The resolution of your monitor determines the possible resolution of the
screen shot.

My 19" monitor is running at a resolution of 1280x1024.  Let's pretend it
actually has a 19" diagonal and a 4:3 size ratio.  That means that the
sides are about 11.25" x 15" .  So the dpi of my monitor is 1280/15 = ~85
or 1024/11.25 = ~75 .  I bet it's 75x75, since the calculations are
approximate, and this is Windows anyway.

If you want 300dpi screenshots then you need to find a 19" monitor that
you can run at 4500x3375 resolution.  Unfortunately there is no such thing,
at least not for the amount of money you have to spend on monitors and
video cards.  (I bet the US military or NSA could afford it, and they 
probably have them already.)

I'm explaining all this so you can see why it's impossible to get a 300dpi
screen shot natively using the hardware that you have.

Your best bet is to take the screenshot and use a good interpolator to
increase the resolution to 300dpi.  Everyone does it, so it's OK!  (?)
You can also force XFree86 to have 100x100 dpi, I think the default is
75x75.  That will get you a small boost.

> 2.  If I take a screen shot and then scale it to a smaller size, how can I 
> keep it clear?  It seems that when I scale it, the *entire* resulting screen 
> shot is blurry.  I understand that things like text may blur, but I've seen 
> other brochures that appear to show screen shots.   The only thought I have 
> is that perhaps these 'screen shots' were actually created in an image 
> editing program and drawn to look like a screen shot.  This seems incredibly 
> stupid to me [since my background is programming], but I can see where a 
> marketing person [who wants everything to look crisp] would use this 
> technique.

Not sure about that.  I would think that a screen shot at 1600x1200 printed
at 300dpi would look fine in a brochure since the physical size of the
image would be 1600/300 = 5.3" x 1200/300 = 4" .  How small do you need to
scale the images?

You could change your desktop resolution to 640x480 then do the screen
capture; your resulting image at 300dpi would be 2.1x1.6" .

Hope this helps,
Jim

-- 
Jim Ockers, P.Eng. (ockers at ockers.net)
Contact info: please see http://www.ockers.net/
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