Working with Images

[Stuart Rogers]

John Sgammato wrote:
> ...

> Note that with SnagIt you can opt to capture the image at other
> resolutions, so you need not change anything in FM. I capture images
> as 200dpi TIFFs, and then import them at 200dpi in my books. I go to
> print, PDF, and online help from a single set of screenshots.

John, your workflow is appropriate, but you're not quite correct on why.

You are not capturing the image "at other resolutions," or really at any 
resolution.  You are capturing a specific number of pixels.  At the time 
of capture, they are *displayed* at your screen resolution (pixels per 
inch, ppi; not dpi).  Put that captured image on another screen with 
different graphics card resolution, and the identical number of pixels 
will be displayed on that screen, with different physical dimensions 
because that screen positions the pixels closer or farther apart 
(different number of ppi).  None of that matters when it comes to 
putting the image in FM.

When you tell SnagIt or FM or Photoshop or any other program that an 
image is xxx dpi, you are simply giving it an instruction to pass along 
to the print device that it should place the dots 1/xxx inch apart.  If 
you tell SnagIt you want the image to be 200 dpi, it tells FM the same 
thing; when you import "at 200dpi", you're telling FM the same thing. 
FM renders an approximation of that on screen, as well as passing the 
instruction on to the print driver.  The image that you captured, unless 
manipulated by some sort of interpolation, can only contain the number 
of pixels that formed the original object on screen.  Telling SnagIt 
200dpi or 50dpi does not change the number of pixels or the size of the 
file; it only changes the distance between dots when printed (and the 
size of FM's on-screen approximation).

Best regards,

-- 
Stuart Rogers
Technical Communicator
Phoenix Geophysics Limited
Toronto, ON, Canada
+1 (416) 491-7340 x 325

srogers phoenix-geophysics com

If it makes things work more easily, why isn't it called lubrican?